Epidemiology Health Dictionary

Epidemiology: From 5 Different Sources


The branch of medicine concerned with the occurrence and distribution of disease, including infectious diseases and noninfectious diseases such as cancer.

In epidemiological studies, the members of a population are counted and described in terms of such variables as race, sex, age, social class, occupation, and marital status. Then the incidence and prevalence of the disease of interest are determined. These observations may be repeated at regular intervals in order to detect changes over time. The result is a statistical record that may reveal links between particular variables and distribution of disease.

In comparative epidemiological studies, two or more groups are chosen. For example, in a study of the link between smoking and lung cancer, one group may consist of smokers and the other of nonsmokers; the proportion with cancer in each group is calculated.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
The study of the various factors influencing the occurrence, distribution, prevention and control of disease, injury and other health-related events in a defined population. Epidemiology utilizes biology, clinical medicine, and statistics in an effort to understand the etiology (causes) and course of illness and/or disease. The ultimate goal of the epidemiologist is, not merely to identify underlying causes of a disease, but to apply findings to disease prevention and health promotion.
Health Source: Community Health
Author: Health Dictionary
The study of disease as it affects groups of people. Originating in the study of epidemics of diseases like CHOLERA, PLAGUE and SMALLPOX, epidemiology is an important discipline which contributes to the control not only of infectious diseases but also of conditions such as heart disease and cancer. Their distributions in populations can provide important pointers to possible causes. The relation between the environment and disease is an essential part of epidemiology. (See ENVIRONMENT AND HEALTH; PUBLIC HEALTH.)
Health Source: Dictionary of Tropical Medicine
Author: Health Dictionary
A science concerned with describing the pattern of occurrence of disease in a population and determining the factors which influence disease prevalence and distribution with the ultimate objective of providing the basis of control of prevention.
Health Source: Medical Dictionary
Author: Health Dictionary
n. the study of the distribution of diseases and determinants of disease in populations. Originally restricted to the study of epidemic infectious diseases, such as smallpox and cholera, it now covers all forms of disease that relate to the environment and ways of life. It thus includes the study of the links between smoking and cancer, and diet and coronary disease, as well as *communicable diseases.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Community Physician

A doctor who works in the specialty that encompasses PREVENTIVE MEDICINE, EPIDEMIOLOGY and PUBLIC HEALTH.... community physician

Data Protection Act 1998

This legislation puts into e?ect the UK European Directive 95/46/EC on the processing of personal data, whether paper or computer records. The Act is based on eight principles, the ?rst of which stipulates that ‘personal data shall be processed fairly and lawfully’. Unfortunately this phrase is open to di?erent interpretations. Clari?cation is required to determine how the common-law duty of con?dentiality affects the health services in the context of using data obtained from patients for research work, especially epidemiological studies (see EPIDEMIOLOGY). Health authorities, trusts and primary care groups in the NHS have appointed ‘Caldicott guardians’ – named after a review of information that identi?es patients. A prime responsibility of the guardians is to agree and review internal protocols for the protection and use of identi?able information obtained from patients. The uncertainties over the interpretation of the legislation require clari?cation, but some experts have suggested a workable solution: to protect patients’ rights, researchers should ensure that data are fully anonymised whenever possible; they should also agree their project design with those responsible for data protection well in advance of its planned starting date. (See ETHICS.)... data protection act 1998

Death Rate

The death (mortality rate) is the number of deaths per 100,000 – or sometimes 10,000 or 1,000 – of the population per year. In 2001 the population of the UK was 59.8 million, of whom 9 million were over 65 and 4.2 million over 75. Females comprised 30.33 million and males 29.47. In 2003 – the latest year for which ?gures are available – the death rate was 7.2 per 1,000 population; in 1980 the ?gure was

11.8. The total mortality comprises individual deaths from di?erent causes: for example, accidents, cancer, coronary artery disease, strokes and suicides. Mortality is often calculated for speci?c groups in epidemiological (see EPIDEMIOLOGY) studies of particular diseases. Infant mortality measures the deaths of babies born alive who die during the ?rst year of life: infant deaths per 1,000 live births were steady at around 5 from 2003–2005.... death rate

Death, Causes Of

The ?nal cause of death is usually the failure of the vital centres in the brain that control the beating of the heart and the act of breathing. The important practical question, however, is what disease, injury or other agent has led to this failure. Sometimes the cause may be obvious – for example, pneumonia, coronary thrombosis, or brain damage in a road accident. Often, however, the cause can be uncertain, in which case a POST-MORTEM EXAMINATION is necessary.

The two most common causes of death in the UK are diseases of the circulatory system (including strokes and heart disease) and cancer.

Overall annual death rates among women in the UK at the start of the 21st century were

7.98 per 1,000 population, and among men,

5.58 per 1,000. Comparable ?gures at the start of the 20th century were 16.3 for women and

18.4 for men. The death rates in 1900 among infants up to the age of four were 47.9 per 1,000 females and 57 per 1,000 males. By 2003 these numbers had fallen to 5.0 and 5.8 respectively. All these ?gures give a crude indication of how the health of Britain’s population has improved in the past century.

Death rates and ?gures on the causes of deaths are essential statistics in the study of EPIDEMIOLOGY which, along with information on the incidence of illnesses and injuries, provides a temporal and geographical map of changing health patterns in communities. Such information is valuable in planning preventive health measures (see PUBLIC HEALTH) and in identifying the natural history of diseases – knowledge that often contributes to the development of preventive measures and treatments for those diseases.... death, causes of

Environmental Health Officer

A local-authority health o?cial specially quali?ed in aspects of environmental health such as clean air, food hygiene, housing, pollution, sanitation and water supplies. He or she is responsible for running the authority’s environmental health department and, when epidemiological advice is needed, the relevant public-health physician acts in a consultative capacity (see EPIDEMIOLOGY; PUBLIC HEALTH).... environmental health officer

Fish

See also Shellfish, Squid.

Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: Low to moderate Saturated fat: Low to moderate Cholesterol: Moderate Carbohydrates: Low Fiber: None Sodium: Low (fresh fish) High (some canned or salted fish) Major vitamin contribution: Vitamin A, vitamin D Major mineral contribution: Iodine, selenium, phosphorus, potassium, iron, calcium

About the Nutrients in This Food Like meat, poultry, milk, and eggs, fish are an excellent source of high- quality proteins with sufficient amount of all the essential amino acids. While some fish have as much or more fat per serving than some meats, the fat content of fish is always lower in saturated fat and higher in unsaturated fats. For example, 100 g/3.5 ounce cooked pink salmon (a fatty fish) has 4.4 g total fat, but only 0.7 g saturated fat, 1.2 g monounsaturated fat, and 1.7 g polyunsaturated fat; 100 g/3.5 ounce lean top sirloin has four grams fat but twice as much saturated fat (1.5 g), plus 1.6 g monounsatu- rated fat and only 0.2 g polyunsaturated fat. Omega-3 Fatty Acid Content of Various Fish (Continued) Fish  Grams/ounce Rainbow trout  0.30 Lake whitefish  0.25 Source: “Food for t he Heart,” American Health, April 1985. Fish oils are one of the few natural food sources of vitamin D. Salmon also has vita- min A derived from carotenoid pigments in the plants eaten by the fish. The soft bones in some canned salmon and sardines are an excellent source of calcium. CAUTION: do not eat the bones in r aw or cook ed fish. the only bones consider ed edible ar e those in the canned products.

The Most Nutritious Way to Serve This Food Cooked, to kill parasites and potentially pathological microorganisms living in raw fish. Broiled, to liquify fat and eliminate the fat-soluble environmental contaminants found in some freshwater fish. With the soft, mashed, calcium-rich bones (in canned salmon and canned sardines).

Diets That May Restrict or Exclude This Food Low-purine (antigout) diet Low-sodium diet (canned, salted, or smoked fish)

Buying This Food Look for: Fresh-smelling whole fish with shiny skin; reddish pink, moist gills; and clear, bulging eyes. The flesh should spring back when you press it lightly. Choose fish fillets that look moist, not dry. Choose tightly sealed, solidly frozen packages of frozen fish. In 1998, the FDA /National Center for Toxicological Research released for testing an inexpensive indicator called “Fresh Tag.” The indicator, to be packed with seafood, changes color if the product spoils. Avoid: Fresh whole fish whose eyes have sunk into the head (a clear sign of aging); fillets that look dry; and packages of frozen fish that are stained (whatever leaked on the package may have seeped through onto the fish) or are coated with ice crystals (the package may have defrosted and been refrozen).

Storing This Food Remove fish from plastic wrap as soon as you get it home. Plastic keeps out air, encouraging the growth of bacteria that make the fish smell bad. If the fish smells bad when you open the package, throw it out. Refrigerate all fresh and smoked fish immediately. Fish spoils quickly because it has a high proportion of polyunsaturated fatty acids (which pick up oxygen much more easily than saturated or monounsaturated fatty acids). Refrigeration also slows the action of microorgan- isms on the surface of the fish that convert proteins and other substances to mucopolysac- charides, leaving a slimy film on the fish. Keep fish frozen until you are ready to use it. Store canned fish in a cool cabinet or in a refrigerator (but not the freezer). The cooler the temperature, the longer the shelf life.

Preparing This Food Fresh fish. Rub the fish with lemon juice, then rinse it under cold running water. The lemon juice (an acid) will convert the nitrogen compounds that make fish smell “fishy” to compounds that break apart easily and can be rinsed off the fish with cool running water. R insing your hands in lemon juice and water will get rid of the fishy smell after you have been preparing fresh fish. Frozen fish. Defrost plain frozen fish in the refrigerator or under cold running water. Pre- pared frozen fish dishes should not be thawed before you cook them since defrosting will make the sauce or coating soggy. Salted dried fish. Salted dried fish should be soaked to remove the salt. How long you have to soak the fish depends on how much salt was added in processing. A reasonable average for salt cod, mackerel, haddock (finnan haddie), or herring is three to six hours, with two or three changes of water. When you are done, clean all utensils thoroughly with hot soap and hot water. Wash your cutting board, wood or plastic, with hot water, soap, and a bleach-and-water solution. For ultimate safety in preventing the transfer of microorganisms from the raw fish to other foods, keep one cutting board exclusively for raw fish, meats, and poultry, and a second one for everything else. Finally, don’t forget to wash your hands.

What Happens When You Cook This Food Heat changes the structure of proteins. It denatures the protein molecules so that they break apart into smaller fragments or change shape or clump together. These changes force moisture out of the tissues so that the fish turns opaque. The longer you cook fish, the more moisture it will lose. Cooked fish flakes because the connective tissue in fish “melts” at a relatively low temperature. Heating fish thoroughly destroys parasites and microorganisms that live in raw fish, making the fish safer to eat.

How Other Kinds of Processing Affect This Food Marinating. Like heat, acids coagulate the proteins in fish, squeezing out moisture. Fish marinated in citrus juices and other acids such as vinegar or wine has a firm texture and looks cooked, but the acid bath may not inactivate parasites in the fish. Canning. Fish is naturally low in sodium, but can ned fish often contains enough added salt to make it a high-sodium food. A 3.5-ounce ser ving of baked, fresh red salmon, for example, has 55 mg sodium, while an equal ser ving of regular can ned salmon has 443 mg. If the fish is can ned in oil it is also much higher in calories than fresh fish. Freezing. When fish is frozen, ice cr ystals form in the flesh and tear its cells so that mois- ture leaks out when the fish is defrosted. Commercial flash-freezing offers some protec- tion by freezing the fish so fast that the ice cr ystals stay small and do less damage, but all defrosted fish tastes drier and less palatable than fresh fish. Freezing slows but does not stop the oxidation of fats that causes fish to deteriorate. Curing. Fish can be cured (preser ved) by smoking, dr ying, salting, or pickling, all of which coagulate the muscle tissue and prevent microorganisms from growing. Each method has its own particular drawbacks. Smoking adds potentially carcinogenic chemicals. Dr ying reduces the water content, concentrates the solids and nutrients, increases the calories per ounce, and raises the amount of sodium.

Medical Uses and/or Benefits Protection against cardiovascular disease. The most important fats in fish are the poly- unsaturated acids k nown as omega-3s. These fatt y acids appear to work their way into heart cells where they seem to help stabilize the heart muscle and prevent potentially fatal arrhythmia (irregular heartbeat). A mong 85,000 women in the long-run n ing Nurses’ Health Study, those who ate fatt y fish at least five times a week were nearly 50 percent less likely to die from heart disease than those who ate fish less frequently. Similar results appeared in men in the equally long-run n ing Physicians’ Health Study. Some studies suggest that people may get similar benefits from omega-3 capsules. Researchers at the Consorzio Mario Negri Sud in Santa Maria Imbaro ( Italy) say that men given a one-gram fish oil capsule once a day have a risk of sudden death 42 percent lower than men given placebos ( “look-alike” pills with no fish oil). However, most nutrition scientists recom- mend food over supplements. Omega-3 Content of Various Food Fish Fish* (3 oz.)  Omega-3 (grams) Salmon, Atlantic  1.8 Anchovy, canned* 1.7 Mackerel, Pacific 1.6 Salmon, pink, canned* 1.4 Sardine, Pacific, canned* 1.4 Trout, rainbow  1.0 Tuna, white, canned* 0.7 Mussels  0.7 * cooked, wit hout sauce * drained Source: Nat ional Fisheries Inst itute; USDA Nut rient Data Laborator y. Nat ional Nut ri- ent Database for Standard Reference. Available online. UR L : http://w w w.nal.usda. gov/fnic/foodcomp/search /.

Adverse Effects Associated with This Food Allergic reaction. According to the Merck Manual, fish is one of the 12 foods most likely to trigger classic food allergy symptoms: hives, swelling of the lips and eyes, and upset stom- ach. The others are berries (blackberries, blueberries, raspberries, strawberries), chocolate, corn, eggs, legumes (green peas, lima beans, peanuts, soybeans), milk, nuts, peaches, pork, shellfish, and wheat (see wheat cer ea ls). NOTE : Canned tuna products may contain sulfites in vegetable proteins used to enhance the tuna’s flavor. People sensitive to sulfites may suf- fer serious allergic reactions, including potentially fatal anaphylactic shock, if they eat tuna containing sulfites. In 1997, tuna manufacturers agreed to put warning labels on products with sulfites. Environmental contaminants. Some fish are contaminated with methylmercury, a compound produced by bacteria that chemically alters naturally occurring mercury (a metal found in rock and soil) or mercury released into water through industrial pollution. The methylmer- cury is absorbed by small fish, which are eaten by larger fish, which are then eaten by human beings. The larger the fish and the longer it lives the more methylmercury it absorbs. The measurement used to describe the amount of methylmercury in fish is ppm (parts per mil- lion). Newly-popular tilapia, a small fish, has an average 0.01 ppm, while shark, a big fish, may have up to 4.54 ppm, 450 times as much. That is a relatively small amount of methylmercur y; it will soon make its way harmlessly out of the body. But even small amounts may be hazardous during pregnancy because methylmercur y targets the developing fetal ner vous system. Repeated studies have shown that women who eat lots of high-mercur y fish while pregnant are more likely to deliver babies with developmental problems. As a result, the FDA and the Environ men- tal Protection Agency have now warned that women who may become pregnant, who are pregnant, or who are nursing should avoid shark, swordfish, king mackerel, and tilefish, the fish most likely to contain large amounts of methylmercur y. The same prohibition applies to ver y young children; although there are no studies of newborns and babies, the young brain continues to develop after birth and the logic is that the prohibition during pregnancy should extend into early life. That does not mean no fish at all should be eaten during pregnancy. In fact, a 2003 report in the Journal of Epidemiology and Community Health of data from an 11,585-woman study at the University of Bristol (England) shows that women who don’t eat any fish while pregnant are nearly 40 percent more likely to deliver low birth-weight infants than are women who eat about an ounce of fish a day, the equivalent of 1/3 of a small can of tuna. One theory is that omega-3 fatty acids in the fish may increase the flow of nutrient-rich blood through the placenta to the fetus. University of Southern California researchers say that omega-3s may also protect some children from asthma. Their study found that children born to asthmatic mothers who ate oily fish such as salmon at least once a month while pregnant were less likely to develop asthma before age five than children whose asthmatic pregnant mothers never ate oily fish. The following table lists the estimated levels of mercury in common food fish. For the complete list of mercury levels in fish, click onto www.cfsan.fda.gov/~frf/sea-mehg.html. Mercury Levels in Common Food Fish Low levels (0.01– 0.12 ppm* average) Anchovies, butterfish, catfish, clams, cod, crab (blue, king, snow), crawfish, croaker (Atlantic), flounder, haddock, hake, herring, lobster (spiny/Atlantic) mackerel, mul- let, ocean perch, oysters, pollock, salmon (canned/fresh frozen), sardines, scallops, shad (American), shrimp, sole, squid, tilapia, trout (freshwater), tuna (canned, light), whitefish, whiting Mid levels (0.14 – 0.54 ppm* average) Bass (salt water), bluefish, carp, croaker ( Pacific), freshwater perch, grouper, halibut, lobster (Northern A merican), mackerel (Spanish), marlin, monkfish, orange roughy, skate, snapper, tilefish (Atlantic), tuna (can ned albacore, fresh/frozen), weakfish/ sea trout High levels (0.73 –1.45 ppm* average) King mackerel, shark, swordfish, tilefish * ppm = parts per million, i.e. parts of mercur y to 1,000,000 parts fish Source: U.S. Food and Drug Administ rat ion, Center for Food Safet y and Applied Nut rit ion, “Mercur y Levels in Commercial Fish and Shellfish.” Available online. UR L : w w w.cfsan.fda. gov/~frf/sea-mehg.ht ml. Parasitical, viral, and bacterial infections. Like raw meat, raw fish may carry various pathogens, including fish tapeworm and flukes in freshwater fish and Salmonella or other microorganisms left on the fish by infected foodhandlers. Cooking the fish destroys these organisms. Scombroid poisoning. Bacterial decomposition that occurs after fish is caught produces a his- taminelike toxin in the flesh of mackerel, tuna, bonito, and albacore. This toxin may trigger a number of symptoms, including a flushed face immediately after you eat it. The other signs of scombroid poisoning—nausea, vomiting, stomach pain, and hives—show up a few minutes later. The symptoms usually last 24 hours or less.

Food/Drug Interactions Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyramine, a substance found in many fermented or aged foods. Tyramine constricts blood vessels and increases blood pressure. If you eat a food such as pickled herring, which is high in tyramine, while you are taking an M AO inhibitor, your body may not be able to eliminate the tyramine and the result may be a hypertensive crisis.... fish

Index

In epidemiology and related sciences, this word usually means a rating scale, e.g. a set of numbers derived from a series of observations of specified variables.... index

Occupational Health, Medicine And Diseases

Occupational health The e?ect of work on human health, and the impact of workers’ health on their work. Although the term encompasses the identi?cation and treatment of speci?c occupational diseases, occupational health is also an applied and multidisciplinary subject concerned with the prevention of occupational ill-health caused by chemical, biological, physical and psychosocial factors, and the promotion of a healthy and productive workforce.

Occupational health includes both mental and physical health. It is about compliance with health-and-safety-at-work legislation (and common law duties) and about best practice in providing work environments that reduce risks to health and safety to lowest practicable levels. It includes workers’ ?tness to work, as well as the management of the work environment to accommodate people with disabilities, and procedures to facilitate the return to work of those absent with long-term illness. Occupational health incorporates several professional groups, including occupational physicians, occupational health nurses, occupational hygienists, ergonomists, disability managers, workplace counsellors, health-and-safety practitioners, and workplace physiotherapists.

In the UK, two key statutes provide a framework for occupational health: the Health and Safety at Work, etc. Act 1974 (HSW Act); and the Disability Discrimination Act 1995 (DDA). The HSW Act states that employers have a duty to protect the health, safety and welfare of their employees and to conduct their business in a way that does not expose others to risks to their health and safety. Employees and self-employed people also have duties under the Act. Modern health-and-safety legislation focuses on assessing and controlling risk rather than prescribing speci?c actions in di?erent industrial settings. Various regulations made under the HSW Act, such as the Control of Substances Hazardous to Health Regulations, the Manual Handling Operations Regulations and the Noise at Work Regulations, set out duties with regard to di?erent risks, but apply to all employers and follow the general principles of risk assessment and control. Risks should be controlled principally by removing or reducing the hazard at source (for example, by substituting chemicals with safer alternatives, replacing noisy machinery, or automating tasks to avoid heavy lifting). Personal protective equipment, such as gloves and ear defenders, should be seen as a last line of defence after other control measures have been put in place.

The employment provisions of the DDA require employers to avoid discriminatory practice towards disabled people and to make reasonable adjustments to working arrangements where a disabled person is placed at a substantial disadvantage to a non-disabled person. Although the DDA does not require employers to provide access to rehabilitation services – even for those injured or made ill at work – occupational-health practitioners may become involved in programmes to help people get back to work after injury or long-term illness, and many businesses see the retention of valuable sta? as an attractive alternative to medical retirement or dismissal on health grounds.

Although a major part of occupational-health practice is concerned with statutory compliance, the workplace is also an important venue for health promotion. Many working people rarely see their general practitioner and, even when they do, there is little time to discuss wider health issues. Occupational-health advisers can ?ll in this gap by providing, for example, workplace initiatives on stopping smoking, cardiovascular health, diet and self-examination for breast and testicular cancers. Such initiatives are encouraged because of the perceived bene?ts to sta?, to the employing organisation and to the wider public-health agenda. Occupational psychologists recognise the need for the working population to achieve a ‘work-life balance’ and the promotion of this is an increasing part of occupational health strategies.

The law requires employers to consult with their sta? on health-and-safety matters. However, there is also a growing understanding that successful occupational-health management involves workers directly in the identi?cation of risks and in developing solutions in the workplace. Trade unions play an active role in promoting occupational health through local and national campaigns and by training and advising elected workplace safety representatives.

Occupational medicine The branch of medicine that deals with the control, prevention, diagnosis, treatment and management of ill-health and injuries caused or made worse by work, and with ensuring that workers are ?t for the work they do.

Occupational medicine includes: statutory surveillance of workers’ exposure to hazardous agents; advice to employers and employees on eliminating or reducing risks to health and safety at work; diagnosis and treatment/management of occupational illness; advice on adapting the working environment to suit the worker, particularly those with disabilities or long-term health problems; and advice on the return to work and, if necessary, rehabilitation of workers absent through illness. Occupational physicians may play a wider role in monitoring the health of workplace populations and in advising employers on controlling health hazards where ill-health trends are observed. They may also conduct epidemiological research (see EPIDEMIOLOGY) on workplace diseases.

Because of the occupational physician’s dual role as adviser to both employer and employee, he or she is required to be particularly diligent with regards to the individual worker’s medical CONFIDENTIALITY. Occupational physicians need to recognise in any given situation the context they are working in, and to make sure that all parties are aware of this.

Occupational medicine is a medical discipline and thus is only part of the broader ?eld of occupational health. Although there are some speci?c clinical duties associated with occupational medicine, such as diagnosis of occupational disease and medical screening, occupational physicians are frequently part of a multidisciplinary team that might include, for example, occupational-health nurses, healthand-safety advisers, ergonomists, counsellors and hygienists. Occupational physicians are medical practitioners with a post-registration quali?cation in occupational medicine. They will have completed a period of supervised in-post training. In the UK, the Faculty of Occupational Medicine of the Royal College of Physicians has three categories of membership, depending on quali?cations and experience: associateship (AFOM); membership (MFOM); and fellowship (FFOM).

Occupational diseases Occupational diseases are illnesses that are caused or made worse by work. In their widest sense, they include physical and mental ill-health conditions.

In diagnosing an occupational disease, the clinician will need to examine not just the signs and symptoms of ill-health, but also the occupational history of the patient. This is important not only in discovering the cause, or causes, of the disease (work may be one of a number of factors), but also in making recommendations on how the work should be modi?ed to prevent a recurrence – or, if necessary, in deciding whether or not the worker is able to return to that type of work. The occupational history will help in deciding whether or not other workers are also at risk of developing the condition. It will include information on:

the nature of the work.

how the tasks are performed in practice.

the likelihood of exposure to hazardous agents (physical, chemical, biological and psychosocial).

what control measures are in place and the extent to which these are adhered to.

previous occupational and non-occupational exposures.

whether or not others have reported similar symptoms in relation to the work. Some conditions – certain skin conditions,

for example – may show a close relationship to work, with symptoms appearing directly only after exposure to particular agents or possibly disappearing at weekends or with time away from work. Others, however, may be chronic and can have serious long-term implications for a person’s future health and employment.

Statistical information on the prevalence of occupational disease in the UK comes from a variety of sources, including o?cial ?gures from the Industrial Injuries Scheme (see below) and statutory reporting of occupational disease (also below). Neither of these o?cial schemes provides a representative picture, because the former is restricted to certain prescribed conditions and occupations, and the latter suffers from gross under-reporting. More useful are data from the various schemes that make up the Occupational Diseases Intelligence Network (ODIN) and from the Labour Force Survey (LFS). ODIN data is generated by the systematic reporting of work-related conditions by clinicians and includes several schemes. Under one scheme, more than 80 per cent of all reported diseases by occupational-health physicians fall into just six of the 42 clinical disease categories: upper-limb disorders; anxiety, depression and stress disorders; contact DERMATITIS; lower-back problems; hearing loss (see DEAFNESS); and ASTHMA. Information from the LFS yields a similar pattern in terms of disease frequency. Its most recent survey found that over 2 million people believed that, in the previous 12 months, they had suffered from an illness caused or made worse by work and that

19.5 million working days were lost as a result. The ten most frequently reported disease categories were:

stress and mental ill-health (see MENTAL ILLNESS): 515,000 cases.

back injuries: 508,000.

upper-limb and neck disorders: 375,000.

lower respiratory disease: 202,000.

deafness, TINNITUS or other ear conditions: 170,000.

lower-limb musculoskeletal conditions: 100,000.

skin disease: 66,000.

headache or ‘eyestrain’: 50,000.

traumatic injury (includes wounds and fractures from violent attacks at work): 34,000.

vibration white ?nger (hand-arm vibration syndrome): 36,000. A person who develops a chronic occu

pational disease may be able to sue his or her employer for damages if it can be shown that the employer was negligent in failing to take reasonable care of its employees, or had failed to provide a system of work that would have prevented harmful exposure to a known health hazard. There have been numerous successful claims (either awarded in court, or settled out of court) for damages for back and other musculoskeletal injuries, hand-arm vibration syndrome, noise-induced deafness, asthma, dermatitis, MESOTHELIOMA and ASBESTOSIS. Employers’ liability (workers’ compensation) insurers are predicting that the biggest future rise in damages claims will be for stress-related illness. In a recent study, funded by the Health and Safety Executive, about 20 per cent of all workers – more than 5 million people in the UK – claimed to be ‘very’ or ‘extremely’ stressed at work – a statistic that is likely to have a major impact on the long-term health of the working population.

While victims of occupational disease have the right to sue their employers for damages, many countries also operate a system of no-fault compensation for the victims of prescribed occupational diseases. In the UK, more than 60 diseases are prescribed under the Industrial Injuries Scheme and a person will automatically be entitled to state compensation for disability connected to one of these conditions, provided that he or she works in one of the occupations for which they are prescribed. The following short list gives an indication of the types of diseases and occupations prescribed under the scheme:

CARPAL TUNNEL SYNDROME connected to the use of hand-held vibrating tools.

hearing loss from (amongst others) use of pneumatic percussive tools and chainsaws, working in the vicinity of textile manufacturing or woodworking machines, and work in ships’ engine rooms.

LEPTOSPIROSIS – infection with Leptospira (various listed occupations).

viral HEPATITIS from contact with human blood, blood products or other sources of viral hepatitis.

LEAD POISONING, from any occupation causing exposure to fumes, dust and vapour from lead or lead products.

asthma caused by exposure to, among other listed substances, isocyanates, curing agents, solder ?ux fumes and insects reared for research.

mesothelioma from exposure to asbestos.

In the UK, employers and the self-employed have a duty to report all occupational injuries (if the employee is o? work for three days or more as a result), diseases or dangerous incidents to the relevant enforcing authority (the Health and Safety Executive or local-authority environmental-health department) under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR). Despite this statutory duty, comparatively few diseases are reported so that ?gures generated from RIDDOR reports do not give a useful indication of the scale of occupational diseases in the UK. The statutory reporting of injuries is much better, presumably because of the clear and acute relationship between a workplace accident and the resultant injury. More than 160,000 injuries are reported under RIDDOR every year compared with just 2,500 or so occupational diseases, a gross underestimate of the true ?gure.

There are no precise ?gures for the number of people who die prematurely because of work-related ill-health, and it would be impossible to gauge the exact contribution that work has on, for example, cardiovascular disease and cancers where the causes are multifactorial. The toll would, however, dwarf the number of deaths caused by accidents at work. Around 250 people are killed by accidents at work in the UK each year – mesothelioma, from exposure to asbestos at work, alone kills more than 1,300 people annually.

The following is a sample list of occupational diseases, with brief descriptions of their aetiologies.

Inhaled materials

PNEUMOCONIOSIS covers a group of diseases which cause ?brotic lung disease following the inhalation of dust. Around 250–300 new cases receive bene?t each year – mostly due to coal dust with or without silica contamination. SILICOSIS is the more severe disease. The contraction in the size of the coal-mining industry as well as improved dust suppression in the mines have diminished the importance of this disease, whereas asbestos-related diseases now exceed 1,000 per year. Asbestos ?bres cause a restrictive lung disease but also are responsible for certain malignant conditions such as pleural and peritoneal mesothelioma and lung cancer. The lung-cancer risk is exacerbated by cigarette-smoking.

Even though the use of asbestos is virtually banned in the UK, many workers remain at risk of exposure because of the vast quantities present in buildings (much of which is not listed in building plans). Carpenters, electricians, plumbers, builders and demolition workers are all liable to exposure from work that disturbs existing asbestos. OCCUPATIONAL ASTHMA is of increasing importance – not only because of the recognition of new allergic agents (see ALLERGY), but also in the number of reported cases. The following eight substances are most frequently linked to occupational asthma (key occupations in brackets): isocyanates (spray painters, electrical processors); ?our and grain (bakers and farmers); wood dust (wood workers); glutaraldehyde (nurses, darkroom technicians); solder/colophony (welders, electronic assembly workers); laboratory animals (technicians, scientists); resins and glues (metal and electrical workers, construction, chemical processors); and latex (nurses, auxiliaries, laboratory technicians).

The disease develops after a short, symptomless period of exposure; symptoms are temporally related to work exposures and relieved by absences from work. Removal of the worker from exposure does not necessarily lead to complete cessation of symptoms. For many agents, there is no relationship with a previous history of ATOPY. Occupational asthma accounts for about 10 per cent of all asthma cases. DERMATITIS The risk of dermatitis caused by an allergic or irritant reaction to substances used or handled at work is present in a wide variety of jobs. About three-quarters of cases are irritant contact dermatitis due to such agents as acids, alkalis and solvents. Allergic contact dermatitis is a more speci?c response by susceptible individuals to a range of allergens (see ALLERGEN). The main occupational contact allergens include chromates, nickel, epoxy resins, rubber additives, germicidal agents, dyes, topical anaesthetics and antibiotics as well as certain plants and woods. Latex gloves are a particular cause of occupational dermatitis among health-care and laboratory sta? and have resulted in many workers being forced to leave their profession through ill-health. (See also SKIN, DISEASES OF.)

Musculoskeletal disorders Musculoskeletal injuries are by far the most common conditions related to work (see LFS ?gures, above) and the biggest cause of disability. Although not all work-related, musculoskeletal disorders account for 36.5 per cent of all disabilities among working-age people (compared with less than 4 per cent for sight and hearing impairment). Back pain (all causes – see BACKACHE) has been estimated to cause more than 50 million days lost every year in sickness absence and costs the UK economy up to £5 billion annually as a result of incapacity or disability. Back pain is a particular problem in the health-care sector because of the risk of injury from lifting and moving patients. While the emphasis should be on preventing injuries from occurring, it is now well established that the best way to manage most lower-back injuries is to encourage the patient to continue as normally as possible and to remain at work, or to return as soon as possible even if the patient has some residual back pain. Those who remain o? work on long-term sick leave are far less likely ever to return to work.

Aside from back injuries, there are a whole range of conditions affecting the upper limbs, neck and lower limbs. Some have clear aetiologies and clinical signs, while others are less well de?ned and have multiple causation. Some conditions, such as carpal tunnel syndrome, are prescribed diseases in certain occupations; however, they are not always caused by work (pregnant and older women are more likely to report carpal tunnel syndrome irrespective of work) and clinicians need to be careful when assigning work as the cause without ?rst considering the evidence. Other conditions may be revealed or made worse by work – such as OSTEOARTHRITIS in the hand. Much attention has focused on injuries caused by repeated movement, excessive force, and awkward postures and these include tenosynovitis (in?ammation of a tendon) and epicondylitis. The greatest controversy surrounds upper-limb disorders that do not present obvious tissue or nerve damage but nevertheless give signi?cant pain and discomfort to the individual. These are sometimes referred to as ‘repetitive strain injury’ or ‘di?use RSI’. The diagnosis of such conditions is controversial, making it di?cult for sufferers to pursue claims for compensation through the courts. Psychosocial factors, such as high demands of the job, lack of control and poor social support at work, have been implicated in the development of many upper-limb disorders, and in prevention and management it is important to deal with the psychological as well as the physical risk factors. Occupations known to be at particular risk of work-related upper-limb disorders include poultry processors, packers, electronic assembly workers, data processors, supermarket check-out operators and telephonists. These jobs often contain a number of the relevant exposures of dynamic load, static load, a full or excessive range of movements and awkward postures. (See UPPER LIMB DISORDERS.)

Physical agents A number of physical agents cause occupational ill-health of which the most important is occupational deafness. Workplace noise exposures in excess of 85 decibels for a working day are likely to cause damage to hearing which is initially restricted to the vital frequencies associated with speech – around 3–4 kHz. Protection from such noise is imperative as hearing aids do nothing to ameliorate the neural damage once it has occurred.

Hand-arm vibration syndrome is a disorder of the vascular and/or neural endings in the hands leading to episodic blanching (‘white ?nger’) and numbness which is exacerbated by low temperature. The condition, which is caused by vibrating tools such as chain saws and pneumatic hammers, is akin to RAYNAUD’S DISEASE and can be disabling.

Decompression sickness is caused by a rapid change in ambient pressure and is a disease associated with deep-sea divers, tunnel workers and high-?ying aviators. Apart from the direct effects of pressure change such as ruptured tympanic membrane or sinus pain, the more serious damage is indirectly due to nitrogen bubbles appearing in the blood and blocking small vessels. Central and peripheral nervous-system damage and bone necrosis are the most dangerous sequelae.

Radiation Non-ionising radiation from lasers or microwaves can cause severe localised heating leading to tissue damage of which cataracts (see under EYE, DISORDERS OF) are a particular variety. Ionising radiation from radioactive sources can cause similar acute tissue damage to the eyes as well as cell damage to rapidly dividing cells in the gut and bone marrow. Longer-term effects include genetic damage and various malignant disorders of which LEUKAEMIA and aplastic ANAEMIA are notable. Particular radioactive isotopes may destroy or induce malignant change in target organs, for example, 131I (thyroid), 90Sr (bone). Outdoor workers may also be at risk of sunburn and skin cancers. OTHER OCCUPATIONAL CANCERS Occupation is directly responsible for about 5 per cent of all cancers and contributes to a further 5 per cent. Apart from the cancers caused by asbestos and ionising radiation, a number of other occupational exposures can cause human cancer. The International Agency for Research on Cancer regularly reviews the evidence for carcinogenicity of compounds and industrial processes, and its published list of carcinogens is widely accepted as the current state of knowledge. More than 50 agents and processes are listed as class 1 carcinogens. Important occupational carcinogens include asbestos (mesothelioma, lung cancer); polynuclear aromatic hydrocarbons such as mineral oils, soots, tars (skin and lung cancer); the aromatic amines in dyestu?s (bladder cancer); certain hexavalent chromates, arsenic and nickel re?ning (lung cancer); wood and leather dust (nasal sinus cancer); benzene (leukaemia); and vinyl chloride monomer (angiosarcoma of the liver). It has been estimated that elimination of all known occupational carcinogens, if possible, would lead to an annual saving of 5,000 premature deaths in Britain.

Infections Two broad categories of job carry an occupational risk. These are workers in contact with animals (farmers, veterinary surgeons and slaughtermen) and those in contact with human sources of infection (health-care sta? and sewage workers).

Occupational infections include various zoonoses (pathogens transmissible from animals to humans), such as ANTHRAX, Borrelia burgdorferi (LYME DISEASE), bovine TUBERCULOSIS, BRUCELLOSIS, Chlamydia psittaci, leptospirosis, ORF virus, Q fever, RINGWORM and Streptococcus suis. Human pathogens that may be transmissible at work include tuberculosis, and blood-borne pathogens such as viral hepatitis (B and C) and HIV (see AIDS/HIV). Health-care workers at risk of exposure to infected blood and body ?uids should be immunised against hapatitis B.

Poisoning The incidence of occupational poisonings has diminished with the substitution of noxious chemicals with safer alternatives, and with the advent of improved containment. However, poisonings owing to accidents at work are still reported, sometimes with fatal consequences. Workers involved in the application of pesticides are particularly at risk if safe procedures are not followed or if equipment is faulty. Exposure to organophosphate pesticides, for example, can lead to breathing diffculties, vomiting, diarrhoea and abdominal cramps, and to other neurological effects including confusion and dizziness. Severe poisonings can lead to death. Exposure can be through ingestion, inhalation and dermal (skin) contact.

Stress and mental health Stress is an adverse reaction to excessive pressures or demands and, in occupational-health terms, is di?erent from the motivational impact often associated with challenging work (some refer to this as ‘positive stress’). Stress at work is often linked to increasing demands on workers, although coping can often prevent the development of stress. The causes of occupational stress are multivariate and encompass job characteristics (e.g. long or unsocial working hours, high work demands, imbalance between e?ort and reward, poorly managed organisational change, lack of control over work, poor social support at work, fear of redundancy and bullying), as well as individual factors (such as personality type, personal circumstances, coping strategies, and availability of psychosocial support outside work). Stress may in?uence behaviours such as smoking, alcohol consumption, sleep and diet, which may in turn affect people’s health. Stress may also have direct effects on the immune system (see IMMUNITY) and lead to a decline in health. Stress may also alter the course and response to treatment of conditions such as cardiovascular disease. As well as these general effects of stress, speci?c types of disorder may be observed.

Exposure to extremely traumatic incidents at work – such as dealing with a major accident involving multiple loss of life and serious injury

(e.g. paramedics at the scene of an explosion or rail crash) – may result in a chronic condition known as post-traumatic stress disorder (PTSD). PTSD is an abnormal psychological reaction to a traumatic event and is characterised by extreme psychological discomfort, such as anxiety or panic when reminded of the causative event; sufferers may be plagued with uncontrollable memories and can feel as if they are going through the trauma again. PTSD is a clinically de?ned condition in terms of its symptoms and causes and should not be used to include normal short-term reactions to trauma.... occupational health, medicine and diseases

Occurrence

In epidemiology, a general term describing the frequency of a disease or other attribute or event in a population, without distinguishing between incidence and prevalence.... occurrence

Public Health

Individuals with health problems go to their doctor, are diagnosed and prescribed treatment. Public-health doctors use epidemiological studies (see EPIDEMIOLOGY, and below) to diagnose the causes of health problems in populations and to plan services to treat the health and disease problems identi?ed. Their concern is often focused particularly on those who are disadvantaged or marginalised, and on the delivery of safe, e?ective and accessible health care: however, to achieve their goal of better health and well-being for everybody, they must also in?uence decision-makers across the whole community.

Central to an understanding of public health is recognition that public-health practitioners are concerned not just with individuals, but also with whole populations – and that improving health care plays only a part of public-health improvement. The health of populations (public health) is also dependent on many factors such as the social, economic and physical environment in which the people live and the nutrition and health care available to them.

For thousands of years, a fundamental feature of civilisations has been to seek to improve the health of the population and protect it from disease. This has led to the development of legal frameworks which di?er widely from country to country, depending on their social and political development. All are concerned to stop the spread of infectious diseases, and to maintain the safety of urban food and water supplies and waste disposal. Most are also associated with housing standards, some form of poverty relief, and basic health care. Some trading standards are often covered, at least in relation to the sale and distribution of poisons and drugs, and to controls on industrial and transport safety – for example, in relation to drinking and driving and car design. Although these varied functions protect the public health and were often originally developed to improve it, most are managerially and professionally separated from today’s public-health departments. So public-health professionals in the NHS, armed with evidence of the cause of a disease problem, must frequently act as advocates for health across many agencies where they play no formal management part. They must also seek to build alliances and add a health perspective to the policies of other services wherever possible.

Epidemiology is the principal diagnostic method of public health. It is de?ned as the study of the distribution and determinants of health-related states in speci?ed populations, and the application of this study to the control of health problems. Public-health practitioners also draw on many other skills, such as those of statisticians, sociologists, anthropologists, economists and policy analysts in identifying and trying to resolve the health problems of the societies they serve. Treatments proposed are likely to extend well beyond the clinic or hospital and may include recommendations for measures to resolve poverty, improve sanitation or housing, control pollution, change lifestyles such as smoking, improve nutrition, or change health services. At times of acute EPIDEMIC, public-health doctors have considerable legal powers granted to enable them to prevent infection from spreading. At other times their work may be more concerned with monitoring, reporting, planning and managing services, and advocating policy changes to politicians so that health is promoted.

The term ‘the public health’ can relate to the state of health of the population, and be represented by measures such as MORTALITY indices

(e.g. perinatal or infant mortality and standardised mortality rates), life expectancy, or measures of MORBIDITY (illness). These can be compared across areas and even countries. Sometimes people refer to a pubic health-care system; this is a publicly funded service, the primary aim of which is to improve health by the use of population-based measures. They may include or be separate from private health-care services for which individuals pay. The structure of these systems varies from country to country, re?ecting di?erent social composition and political priorities. There are, however, some general elements that can be identi?ed:

Surveillance The collection, collation and analysis of data to provide useful information about the distribution and causes of health and disease and related factors in populations. These activities form the basis of epidemiology, which is the diagnostic backbone of public-health practice.

Intervention The design, advocacy and implementation of policies to improve health. This may be through the provison of PREVENTIVE MEDICINE, environmental measures, in?uencing the behaviour of individuals, or the provision of appropriate services to limit disability and handicap. It will lead to advocacy for health, promoting change in many areas of policy including, for example, taxation and improved housing and employment opportunities.

Evaluation Assessment of the ?rst two steps to assess their impact in terms of e?ectiveness, e?ciency, acceptability, accessibility, value for money or other indicators of quality. This enables the programme to be reviewed and changed as necessary.

The practice of public health The situation in the United Kingdom will be described as, even though systems vary, it will give a general impression of the type of work covered. HISTORY Initially, public-health practice related to food, the urban environment and the control of infectious diseases. Early examples include rules in the Bible about avoiding certain foods. These were probably based on practical experience, had gradually been adopted as sensible behaviour, become part of culture and ?nally been incorporated into religious laws. Other examples are the regulations about quarantine for PLAGUE and LEPROSY in the Middle Ages, vaccination against SMALLPOX introduced by William Jenner, and Lind’s use of citrus fruits to prevent SCURVY at sea in the 18th century.

It was during the 19th century, in response to the health problems arising from the rapid growth of urban life, that the foundations of a public-health system were created. The ‘sanitary’ concept was fundamental to these developments. This suggested that overcrowding in insanitary conditions was the cause of most disease epidemics and that improved sanitation measures such as sewerage and clean water supplies would prevent them. Action to introduce such measures were often initiated only after epidemics spread out of the slums and into wealthier and more powerful families. Other problems such as the stench of the River Thames outside the Houses of Parliament also led to a demand for e?ective sanitary control measures. Successive public-health laws were passed by Parliament, initially about sanitation and housing, and then, as scienti?c knowledge grew, about bacterial infections.

In the middle of the 19th century the ?rst medical o?cers of health were appointed with responsibility to report regularly and advise local government about the measures needed to control disease and improve health. Their scope and responsibility widened as society changed and took on a wider welfare role. After more than a century they changed as part of the reforms of the NHS and local government in the 1960s and became more narrowly focused within the health-care system and its management. Increased recognition of the multifactorial causes, costs and limitations of treatment of conditions such as cancer and heart disease, and the emergence of new problems such as AIDS/HIV and BOVINE SPONGIFORM ENCEPHALOPATHY (BSE) have again showed the importance of prevention and a broader approach to health. With it has come recognition that, while disease may be the justi?cation for action, a narrow diseasetreatment-based approach is not always the most e?ective or economic solution. The role of the director of public health (the successor to the medical o?cer of health) is again being expanded, and in 1997 – for the ?rst time in the UK – a government Minister for Public Health was appointed. This reffects not only a greater priority for public health, but also a concern that the health effects of policy should be considered across all parts of government.

(See also ENVIRONMENT AND HEALTH.)... public health

Rate

A measure of the frequency of a phenomenon. In epidemiology, demography and vital statistics, a rate is an expression of the frequency with which an event occurs in a defined population. Rates are usually expressed using a standard denominator such as 1000 or 100 000 persons. Rates may also be expressed as percentages. The use of rates rather than raw numbers is essential for comparison of experience between populations at different times or in different places, or among different classes of persons.... rate

Retrospective Study

The opposite of a PROSPECTIVE STUDY, involving a historical review of the characteristics of a collection of people to assess MORBIDITY, often by obtaining and analysing their casenotes. The procedure is commonly used in studying the EPIDEMIOLOGY of disease.... retrospective study

Specificity

An epidemiological term (see EPIDEMIOLOGY) describing the extent to which a SCREENING TEST for the presence of the precursors of disease – for example, pre-malignant cells in the cervix – throws up false positives. A speci?c test has few false positives.... specificity

Measles

Measles, formerly known as morbilli, is an acute infectious disease occurring mostly in children and caused by an RNA paramyxovirus.

Epidemiology There has been a dramatic fall in the number of sufferers from 1986, when more than 80,000 cases were reported. This is due to the introduction in 1988 of the measles, mumps and rubella vaccine (MMR VACCINE – see also IMMUNISATION); 1990, when the proportion of children immunised reached 90 per cent, was the ?rst year in which no deaths from measles were reported. Even so, fears of side-effects of the vaccine against measles – including scienti?cally unproven and discredited claims of a link with AUTISM – mean that some children in the UK are not being immunised, and since 2002 local outbreaks of measles have been reported in a few areas of the UK. Side-effects are, however, rare and the government is campaigning to raise the rate of immunisation, with GPs being set targets for their practices.

There are few diseases as infectious as measles, and its rapid spread in epidemics is no doubt due to the fact that this viral infection is most potent in the earlier stages. Hence the dif?culty of timely isolation, and the readiness with which the disease is spread, which is mostly by infected droplets. In developing countries measles results in the death of more than a million children annually.

Symptoms The incubation period, during which the child is well, lasts 7–21 days. Initial symptoms are CATARRH, conjunctivitis (see EYE, DISORDERS OF), fever and a feeling of wretchedness. Then Koplik spots – a classic sign of measles – appear on the roof of the mouth and lining of the cheeks. The macular body rash, typical of measles, appears 3–5 days later. Common complications include otitis media (see under EAR, DISEASES OF) and PNEUMONIA. Measles ENCEPHALITIS can cause permanent brain damage. A rare event is a gradual dementing disease (see DEMENTIA) called subacute sclerosing panenecephalitis (SSPE).

Treatment Isolation of the patient and treatment of any secondary bacterial infection, such as pneumonia or otitis, with antibiotics. Children usually run a high temperature which can be relieved with cool sponging and antipyretic drugs. Calamine lotion may alleviate any itching.... measles

Research

In medicine, the collation and assessment of existing facts and knowledge, and the critical systematic investigation of the normal and abnormal functioning of the body, along with the EPIDEMIOLOGY of diseases and disorders affecting it – the aim being to increase the sum of knowledge in respect of the prevention, diagnosis and treatment of disease.

Ethics of research Although Britain has had legislation governing aspects of research on animals since the 19th century, there is no over-arching statute regulating research on humans and human material. Such activity is covered in law by the vaguely de?ned common-law concept of consent, and by piecemeal legislation such as the DATA PROTECTION ACT 1998 and the HUMAN FERTILISATION & EMBRYOLOGY ACT 1990. Nevertheless, extensive and very detailed ethical guidance on aspects of research has been published by a wide range of national and international organisations (see ETHICS COMMITTEES). Several basic principles feature in all statements about research ethics: these include the importance of ensuring that research is independently and rigorously scrutinised by appropriately constituted ethics committees; verifying that any risk to the research subject is reasonable in relation to the anticipated bene?t; and ensuring that all e?orts are made to minimise possible harm. The research subject’s willingness to tolerate some risk does not relieve researchers of the responsibility of making sure that all risks are kept to a minimum. Above all, a key feature of ethical research has involved seeking informed consent from research participants. This rule, initially applied to actual involvement by human subjects in research, has gradually been extended to include seeking informed consent from patients or from their relatives to the use of data and to the use of human organs and tissue in research, including after POST-MORTEM EXAMINATION. (See also EVIDENCE-BASED MEDICINE.)... research

Cancer – Testicles

Rare, but increasing in most countries. Three main types: teratomas, seminomas and lymphomas. The latter affect older men.

Symptoms. A hard usually painless mass in the scrotum can give rise to gynaecomastia – abnormal enlargement of the male breasts.

Of possible value. Alternatives: – Abundant herb teas – Cornsilk, Red Clover, Violet leaves.

Decoction. Echinacea 2; Kava Kava 1; Sarsaparilla 1. Mix. Half an ounce (15g) to 1 pint (500ml) water simmered gently 20 minutes. Cup thrice daily.

Formula. Sarsaparilla 2; Kava Kava l; Pulsatilla half; Thuja quarter. Mix. Dose: Powders: 500mg (two 00 capsules or one-third teaspoon). Liquid extracts: 1 teaspoon. Tinctures: 2 teaspoons. Thrice daily. Vinchristine.

Diet. See: DIET – CANCER. Researchers from Cambridge University found that an extra pint of milk a day during adolescence was associated with 2 and a half times increased risk of testicular cancer. (Journal of Epidemiology and Community Health, Oct. 1993)

Treatment by or in liaison with a general medical practitioner. ... cancer – testicles

Virology

The study of viruses and the epidemiology and treatment of diseases caused by viruses.

In a more restricted sense, virology also refers to the isolation and identification of viruses to diagnose specific viral infections.

Depending on the type of virus, this may involve growing viruses in cultures of human or animal cells, staining or microscopic examination of specimens containing viruses, or immunoassay techniques.... virology

Public Health Ethics

the ethics of population (as opposed to individual) health, including issues related to epidemiology, disease prevention, health promotion, *justice, and *equality. Public health ethics is commonly concerned with the tensions between individual *autonomy and *communitarianism and/or *utilitarianism.... public health ethics

Public Health Medicine

the specialty concerned with preventing disease and improving health in populations as distinct from individuals. Formerly known as community medicine or social medicine, it includes *epidemiology, *health promotion, *health service planning, *health protection, and evaluation. See also public health consultant.... public health medicine

Rheumatoid Arthritis

A chronic in?ammation of the synovial lining (see SYNOVIAL MEMBRANE) of several joints, tendon sheaths or bursae which is not due to SEPSIS or a reaction to URIC ACID crystals. It is distinguished from other patterns of in?ammatory arthritis by the symmetrical involvement of a large number of peripheral joints; by the common blood-?nding of rheumatoid factor antibody; by the presence of bony erosions around joints; and, in a few, by the presence of subcutaneous nodules with necrobiotic (decaying) centres.

Causes There is a major immunogenetic predisposition to rheumatoid arthritis in people carrying the HLA-DR4 antigen (see HLA SYSTEM). Other minor immunogenetic factors have also been implicated. In addition, there is a degree of familial clustering which suggests other unidenti?ed genetic factors. Genetic factors cannot alone explain aetiology, and environmental and chance factors must be important, but these have yet to be identi?ed.

Epidemiology Rheumatoid arthritis more commonly occurs in women from the age of 30 onwards, the sex ratio being approximately 4:1. Typical rheumatoid arthritis may occur in adolescence, but in childhood chronic SYNOVITIS usually takes one of a number of di?erent patterns, classi?ed under juvenile chronic arthritis.

Pathology The primary lesion is an in?ammation of the synovial membrane of joints. The synovial ?uid becomes diluted with in?ammatory exudate: if this persists for months it leads to progressive destruction of articular CARTILAGE and BONE. Cartilage is replaced by in?ammatory tissue known as pannus; a similar tissue invades bone to form erosions. Synovitis also affects tendon sheaths, and may lead to adhesion ?brosis or attrition and rupture of tendons. Subcutaneous and other bursae may be involved. Necrobiotic nodules also occur at sites outside synovium, including the subcutaneous tissues, the lungs, the pericardium and the pleura.

Clinical features Rheumatoid arthritis varies from the very mild to the severely disabling. Many mild cases probably go undiagnosed. At least 50 per cent of patients continue to lead a reasonably normal life; around 25 per cent are signi?cantly disabled in terms of work and leisure activities; and a minority become markedly disabled and are limited in their independence. There is often an early acute phase, followed by substantial remission, but in other patients gradual step-wise deterioration may occur, with progressive involvement of an increasing number of joints.

The diagnosis of rheumatoid arthritis is largely based on clinical symptoms and signs. Approximately 70 per cent of patients have rheumatoid factor ANTIBODIES in the SERUM but, because of the large number of false positives and false negatives, this test has very little value in clinical practice. It may be a useful pointer to a worse prognosis in early cases if the level is high. X-RAYS may help in diagnosing early cases and are particularly helpful when considering surgery or possible complications such as pathological fracture. Patients commonly develop ANAEMIA, which may be partly due to gastrointestinal blood loss from antiin?ammatory drug treatment (see below).

Treatment involves physical, pharmacological, and surgical measures, together with psychological and social support tailored to the individual patient’s needs. Regular activity should be maintained. Resting of certain joints such as the wrist with splints may be helpful at night or to assist prolonged manual activities. Sound footwear is important. Early use of antirheumatic drugs reduces long-term disability. Drug treatment includes simple ANALGESICS, NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), and slow-acting drugs including GOLD SALTS (in the form of SODIUM AUROTHIOMALATE), PENICILLAMINE, SULFASALAZINE, METHOTREXATE and AZATHIOPRINE.

The non-steroidal agents are largely e?ective in reducing pain and early-morning sti?ness, and have no e?ect on the chronic in?ammatory process. It is important, especially in the elderly, to explain to patients the adverse effects of NSAIDs, the dosage of which can be cut by prescribing paracetamol at the same time. Combinations of anti-rheumatic drugs seem better than single agents. The slow-acting drugs take approximately three months to act but have a more global e?ect on chronic in?ammation, with a greater reduction in swelling and an associated fall in erythrocyte sedimentation rate (ESR) and rise in the level of HAEMOGLOBIN. Local CORTICOSTEROIDS are useful, given into individual joints. Systemic corticosteroids carry serious problems if continued long term, but may be useful under special circumstances. Much research is currently going on into the use of tumour necrosis factor antagonists such as INFLIXIMAB and etanercept, but their precise role remains uncertain.... rheumatoid arthritis

Vector

In infectious disease epidemiology, an insect or any living carrier that transports an infectious agent from an infected individual or its wastes to a susceptible individual or its food or immediate surroundings.... vector

Cancer - Breast

Commonest form of cancer in women. Overall mortality remains about 50 per cent at five years. Appears to run in families. Strikes hard unmarried women. Married women who have no children. Those who do not nurse their babies, or who are infertile and have no child before thirty. Eight out of ten chest lumps are benign.

Symptoms. A small lump comes to light while washing, a discharge from the nipple, change in nipple size and colour, irregular contour of the breast surface. Though tissue change is likely to be a cyst, speedy diagnosis and treatment are necessary. Some hospital physicians and surgeons are known to view favourably supportive herbal aids, and do not always think in terms of radical mastectomy. Dr Finlay Ellingwood, Chicago physician (1916) cured a case by injection of one dram Echinacea root extract twice a week into the surrounding tissues.

The condition is believed to be due to a number of causes including suppression of ovulation and oestrogen secretion in pregnant and lactating women. A high fat diet is suspected of interference with the production of oestrogen. Some women are constitutionally disposed to the condition which may be triggered by trauma or emotional shock. Increase in incidence in older women has been linked with excessive sugar consumption. “Consumption overwhelms the pancreas which has to ‘push it out’ to all parts of the body (when broken down by the digestive process) whether they need it or not. The vital organs are rationed according to their requirements of nutrients from the diet. What is left over has to ‘go into store elsewhere’. And the breast is forced to take its share and store it. If it gets too much, for too long, it may rebel!” (Stephen Seely, Department of Bacteriology and Virology, Manchester)

“Women who nurse their babies less than one month are at an increased risk for breast cancer. The longer a woman breast-feeds – no matter what her age – the more the risk decreases. (Marion Tompson, co-founder, The La Leche League, in the American Journal of Epidemiology)

Lactation reduces the risk of pre-menopausal breast cancer. (Newcomb P.A. et al New England Journal of Medicine, 330 1994)

There is currently no treatment to cure metastatic breast cancer. In spite of chemotherapy, surgery and radiotherapy survival rate has not diminished. Herbs not only have a palliative effect but, through their action on hormone function offer a positive contribution towards overcoming the condition. Their activity has been widely recorded in medical literature. Unlike cytotoxic drugs, few have been known to cause alopecia, nausea, vomiting or inflammation of the stomach.

Treatment by a general medical practitioner or oncologist.

Special investigations. Low radiation X-ray mammography to confirm diagnosis. Test for detection of oestrogen receptor protein.

Treatment. Surgery may be necessary. Some patients may opt out from strong personal conviction, choosing a rigid self-disciplined approach – the Gentle Way. Every effort is made to build up the body’s natural defences (immune system).

An older generation of herbalists believed tissue change could follow a bruise on the breast, which should not be neglected but immediately painted with Tincture Arnica or Tincture Bellis perennis.

Vincristine, an alkaloid from Vinca rosea (Catharanthus roseus) is used by the medical profession as an anti-neoplastic and anti-mitotic agent to inhibit cell division.

Of possible therapeutic value. Blue Flag root, Burdock root, Chaparral, Clivers, Comfrey root, Echinacea, Figwort, Gotu Kola, Marshmallow root, Mistletoe, Myrrh, Prickly Ash bark, Red Clover, Thuja, Wild Violet, Yellow Dock.

Tea. Equal parts: Red Clover, Clivers, Gotu Kola, Wild Violet. 1 heaped teaspoon to each cup boiling water; infuse 5-15 minutes. 3 or more cups daily.

Decoctions. Echinacea, Blue Flag root, Queen’s Delight, Yellow Dock.

Tablets/capsules. Blue Flag root, Echinacea, Poke root, Mistletoe.

Formula. Echinacea 2; Gotu Kola 1; Poke root 1; Mistletoe 1; Vinca rosea 1. Mix. Dose: Powders: 500mg (two 00 capsules or one-third teaspoon). Liquid extracts: 1 teaspoon. Tinctures: 2 teaspoons. Thrice daily and at bedtime. According to progress of the disease, increase dosage as tolerated.

Maria Treben’s tea. Parts: Marigold (3), Yarrow 1; Nettles 1. Mix. 2 teaspoons to each cup boiling water. 1 cup as many times daily as tolerated.

William Boericke, M.D. recommends Houseleek. E.H. Ruddock M.D. favours Figwort.

Topical. Treatments believed to be of therapeutic value or for use as a soothing application.

(1) Cold poultice: Comfrey root.

(2) Poultice of fresh Marshmallow root pulped in juicer.

(3) Injection of Extract Greater Celandine (Chelidonium), locally, gained a reputation in the Eclectic school.

(4) The action of Blood root (Sanguinaria) is well known as a paint or injection.

(5) Ragwort poultice: 2oz Ragwort boiled in half a pint potato water for 15 minutes. See: POULTICE.

(6) Popular Russian traditional remedy: Badiaga (Spongilla fluviatilis), fresh water sponge gathered in the autumn; dried plant rubbed to a powder. Poultice.

(7) Maria Treben’s Poultice: Carefully washed fresh Plantain leaves, pulped, and applied direct to the lesion.

(8) If lymph glands are affected, apply Plantain poultice to glands.

(9) Dr Brandini’s treatment. Dr Brandini, Florence, used 4 grains Citric Acid (prepared from lemons) in 1oz (30ml) water for ulcerated cancer of the breast considered incurable. “The woman’s torments were so distressing that neither she nor other patients could get any rest. Applying lint soaked in the solution, relief was instantaneous. Repeated, it was successful.”

(10) Circuta leaves. Simmered till soft and mixed with Slippery Elm bark powder as a poultice morning and night.

(11) Decoction. Simmer gently Yellow Dock roots, fine cut or powdered, 1oz to 1 pint, 20 minutes. Saturate lint or suitable material and apply.

(12) Yellow Dock ointment. Half ounce Lobelia seed, half ounce Yellow Dock root powder. Baste into an ointment base. See: OINTMENT BASE.

(13) Infusion, for use as a wash. Equal parts: Horsetail, Red Clover, Raspberry leaves. 1oz to 1 pint boiling water infuse 15 minutes.

(14) Dr Christopher’s Ointment. Half an ounce White Oak, half an ounce Garden Sage, half an ounce Tormentil, half an ounce Horsetail, half an ounce Lemon Balm. Method: Boil gently half an hour in quart water, strain. Reduce to half a pint by simmering. Add half a pound honey. Bring to boil. Skim off scum. Allow cool. Apply: twice daily on sores.

(15) Dr Finlay Ellingwood. Poke root juice. “Fresh juice from the stems, leaves and roots applied directly to diseased tissue. Exercises a selective action; induces liquefaction and promotes removal, sometimes healing the open wound and encouraging scar formation. Masses of such tissue have been known to be destroyed in a few weeks with only a scar, with no other application but the fresh juice. Produces pain at first, but is otherwise harmless.”

(16) Lesion painted with Mandrake resin. (American Podophyllum)

(17) Dust affected parts with Comfrey powder. Mucilage from Comfrey powder or crushed root with the aid of a little milk. See: COMFREY.

(18) Dr Samuel Thomson’s Cancer Plaster. “Take heads of Red Clover and fill a kettle. Boil in water for one hour. Remove and fill kettle with fresh flower heads. Boil as before in the same liquor. Strain and press heads to express all the liquor. Simmer over a low fire till of the consistency of tar. It must not burn. Spread over a piece of suitable material.”

(19) Wipe affected area with cut Houseleek. (Dr Wm Boericke)

(20) Chinese Herbalism. Take 1-2 Liang pulverised liao-ko-wang (Wickstroemia indica), mix with cold boiled water or rice wine for local compress. Also good for mastitis.

(21) Italian women once used an old traditional remedy – Fenugreek tea.

(22) A clinical trial of Vitamin D provided encouraging results. Patients with locally advanced breast cancer were given a highly active Vitamin D analogue cream to rub on their tumours. “It was effective in one third of the tumours,” said Professor Charles Coombes, clinical oncologist, Charing Cross Hospital, London.

Diet. “A diet rich in cereal products (high in dietary fibre) and green leafy vegetables (antioxidants) would appear to offer women some protection against breast cancer due to the relation between fibre and oestrogen metabolism. Meat-free diet. In a study of 75 adolescent girls, vegetarians were found to have higher levels of a hormone that women suffering from breast cancer often lack. (Cancer Research) Supplements. Daily. Chromium. Selenium (600mcg). Zinc chelate (100mg morning and evening). Beta carotene. “Low levels of Selenium and Vitamins A and E are shown in breast cancer cases.” (British Journal of Cancer 49: 321-324, 1984).

Vitamins A and D inhibit virus penetration in healthy cell walls. Multivitamin combinations should not include Vitamin B12, production of which in the body is much increased in cancerous conditions. Vitamins B-complex and C especially required.

Note: A link between sugar consumption and breast cancer has been reported by some authorities who suggest that countries at the top of the mortality table are the highest also in sugar consumption; the operative factor believed to be insulin.

Screening. Breast screening should be annual from the age of forty.

General. Mothers are encouraged to breast-feed children for the protection it offers against mammary malignancy. (Am.J. Obstet. Gyn. 15/9/1984. 150.)

Avoidance of stress situations by singing, playing an instrument. Adopt relaxation techniques, spiritual healing and purposeful meditation to arouse the immune system; intensive visualisation. Avoid the carcinogens: smoking, alcohol.

Information. Breast Cancer Care. Free Help Line. UK Telephone: 0500 245345. ... cancer - breast

Gall-stones

Any obstruction to the free flow of bile causes stagnation within the gallbladder. Deposits of bile pigments form (bile sand). Under chemical change, these small masses become encrusted with cholesterol and converted into gall-stones. Common in overweight middle-aged women, “fair, fat and forty”. Fifteen per cent of the world’s population are affected. Pain may be mistaken for heart disorder.

Stones are of two main types: cholesterol and bile pigment. Cholesterol stones are composed of about 70 per cent cholesterol. Bile pigment stones are brittle and hard and brown or black. Stones cause gall duct obstruction, inflammation of the gall bladder and biliary colic.

Biliary colic can be one of the most excruciatingly painful conditions known.

Symptoms: extreme tenderness in upper right abdomen, dyspepsia, flatulence, vomiting, sweating, thirst, constipation. Prolonged obstruction leads to jaundice. Pain should be evaluated by a competent authority: doctor or hospital. Large stones will require surgery.

Alternatives. Combinations should include a remedy for increasing the flow of bile (cholagogue); to disperse wind (carminative); and for painful spasm.

BHP (1983) – Barberry, Greater Celandine, Balmony, Wahoo, Boldo, Chiretta, Dandelion.

Indicated: Cholagogues, Bitters to meet reduced secretion of bile. To prevent infection – Echinacea. Preventative measure for those with tendency to form stone – 2 Blue Flag root tablets/capsules, or half a teaspoon Glauber salts in morning tea, or 420mg Silymarin (Milk Thistle), daily.

Teas. Boldo, Black Horehound, Horsetail, Parsley Piert, Milk Thistle, Strawberry leaves, Wood Betony. Dr Hooper’s case: “An Indian Army officer suffered much from gall-stones and was advised to take Dandelion tea every day. Soon the symptoms left him and he remained free from them for over 20 years.” (John Clarke, MD)

Decoction. 1oz each: Milk Thistle, Centuary, Dandelion root, in 3 pints water. Bring to boil. Simmer down to 2 pints. Strain. One cup 3 times daily an hour before meals.

Tablets/capsules. Cramp bark (acute spasm). Wild Yam (spasmolytic and bile liquifier).

Powders. Equal parts: Cramp bark, Wahoo, Dandelion. Dose: 750mg (three 00 capsules or half a teaspoon) every 2 hours for acute cases.

Study. Silymarin 420mg daily on patients with a history of gall-stones. Results showed reduced biliary cholesterol concentrations and considerably reduced bile saturation index. (Nassuato, G. et al, Journal of Hepatology 1991, 12)

Captain Frank Roberts. Advises Olive oil and Lemon treatment (see below) followed by his prescription: Liquid Extract Fringe Tree 1oz (30ml); Liquid Extract Wahoo 1oz; Liquid Extract Kava- Kava 1oz; Liquid Extract Black root 1oz; Honey 2oz. Dose: teaspoon after meals – minimum 3 meals daily – in wineglass tepid water.

Liquid Extract Barberry: 20-60 drops in water every 2 hours.

Finlay Ellingwood MD. Liquid Extract Fringe Tree bark 10ml; Liquid Extract Greater Celandine 10ml; Tincture Gelsemium 5ml. Dose: 10 drops in water half hourly for acute cases.

Alfred Vogel. Suggests Madder root, Clivers and Knotgrass have solvent properties.

Juices believed to have solvent properties: Celery, Parsley, Beet, Carrot, Radish, Lemon, Watercress, Tomato.

Olive oil and Lemon treatment. Set aside a day for the operation. Take breakfast. No meals for the rest of the day. About 6pm commence by drinking 1 or 2 ounces of the oil. Follow with half-1 cup fresh Lemon juice direct from the fruit in a little warm water. Dilute no more than necessary. Alternate drinks of Olive oil and Lemon juice throughout the evening until one pint or more Olive oil, and juice of 8-9 Lemons been consumed. Drink at intervals of 10 minutes to half an hour. Following 3 days pass stools into a chamber and wash well in search for stones and ‘bile sand’.

Practitioner. For spasm on passing stone: Tincture Belladonna: 20 drops in 100ml water: 1 teaspoon hourly.

Compresses: hot wet. Castor oil packs, or hot water packs over painful area.

Enema. Strong Catmint tea – 2 pints.

Diet. Commence with 3 day juice-fast: no solid food. Turmeric used at table as a condiment. Avoid cheese, sugar. Vegetarian diet. Studies show those who eat meat are twice as likely to develop stone. Less saturated fat and more fibre. Vegetable margarine instead of butter. Dandelion coffee or juices in place of caffeine beverages. High vegetable protein; high carbohydrate; high fibre. Oats. Artichokes, honey, molasses, unrefined cereals. Vegetable oil in cooking.

Supplements. Daily. Vitamin C, 2-3g. Vitamin E, 500iu. Choline 1g.

Note: Subjects with a sensitive skin who enjoyed sunbathing are at a raised risk of having gallstones. (Journal of Epidemiology and Community Health)

Gall-stones may form if weight is lost rapidly when on a low calorie diet. ... gall-stones

Infertility

Failure of two people to bring about a pregnancy after one year of normal sexual intercourse. Where the cause is known accurate and effective treatment is possible. For instance, where it is likely to be caused by candida, focus on that condition with anti-fungals.

Causes (female). Absence of menses, dry vaginal entrance, tension, stress, tiredness, deformed or retroverted womb, cervical polyps, inflammation of the cervix or ovaries, fibroids, cystic ovaries, diabetes, drugs, steroids, psychogenic factors. Women who use intra-uterine devices may become infertile from tubal infection. The Pill affects fertility. Vitamin E deficiency. Professor Richard Morisset (World Health Organisation) asserts STD’s account for more than 50 per cent infertility in women. Alcohol is a factor.

Causes (male). Inadequate seman, testicular or prostate infection, orchitis (from past mumps), kidney failure, chronic lung disease from smoking, thyroid deficiency, liver and other infections, calcium or Vitamin E deficiency. Low sperm count is found in regular drinkers of alcohol. 30 per cent cases of infertility are found to be due to the male.

“Women who drink more than one cup of coffee a day may find it harder to become pregnant.” (American study reported in The Guardian, 28.12.88)

“Vegetarian women have lower levels of oestrogen. The amount of fibre women eat is believed to affect oestrogen levels in their blood.” (Dr Elwyn Hughes, University of Wales Institute of Science and Technology)

“Drinking more than four cups of coffee a day and smoking more than 20 cigarettes could be a dangerous combination for male fertility.” (Research study, North Carolina, USA)

Women whose mothers smoked when they were pregnant are only 50 per cent as fertile as women who were not exposed (when in the uterus) to a mother’s tobacco smoke. (C. Weinberg, “Reduced Fecundity in Women with Prenatal exposure to cigarette smoking.” American Journal of Epidemiology 1989; 129 p1072)

Margarine has been implicated in low sperm counts.

Alternatives. Endocrine balancers.

Female. Tea. Equal parts: herbs – Motherwort, Agnus Castus and Oats. Mix. 2 teaspoons to each cup boiling water; infuse 15 minutes. Dose, 1 cup 2-3 times daily.

Tablets: Agnus Castus, dosage as on bottle.

Liquid Extracts: equal parts Agnus Castus and Helonias: 1 teaspoon in water 2-3 times daily.

Maria Treben: 25 drops fresh Mistletoe juice in water, on empty stomach, night and morning.

External: Castor oil abdominal packs twice weekly.

Male. Ginseng, Gotu Kola, or the traditional combination of Damiana, Saw Palmetto and Kola. Tablets, liquid extracts, powders or tinctures. Tinctures (practitioner): Capsicum Fort BPC 5ml; Saw Palmetto (1:5) 10ml; Damiana (1:5) 50ml; Prickly Ash (1:5) 10ml. Aqua to 100ml. 1 teaspoon in water, thrice daily. (Arthur Hyde FNIMH)

An orange a day helps keep sperm OK. (Important role of Vitamin C – New Scientist 1992 NO.1812 p20)

Fasting. Mrs A. Rylin, Sweden, had been trying to conceive for 2 years. Conventional medicine proved ineffective until both she and her husband decided to fast for ten days. Within a month she conceived. Other successes reported.

Diet. (For both partners) Vitamin A foods. Wholefoods, oatmeal products (breakfast oats, etc). Regular raw food days. No alcohol. The key mineral for infertility is zinc, a deficiency of which may be made up with bran which is not only high in zinc but in soluble fibre. Not to eat any green peas, which are mildly contraceptive.

Supplements. Daily. Vitamin C (1 gram). Vitamin E (500iu). One B-complex tablet, including B6. The calcium ion is the key regulator of human sperm function – Calcium Lactate 300mg (2 tablets thrice daily at meals). Zinc – 2 tablets or capsules at night. Folic acid, 400mcg. Dolomite. Iron.

Notes. Consider Vitamin B12 and Iron deficiency when evaluating anaemia in infertile couples.

20 percent of men suffer infertility and produce high levels of superoxide radicals in their semen. Vitamin E, an antioxidant, is believed to mop up their superoxide radicals.

Observe sign of zinc deficiency: white flecks on nails. ... infertility

Occupational Medicine

A branch of medicine dealing with the effects of various occupations on health, and with an individual’s capacity for particular types of work. It includes prevention of occupational disease and injury and the promotion of health in the working population. Epidemiology is used to analyse patterns of sickness absence, injury, illness, and death. Clinical techniques are used to monitor the health of a particular workforce. Assessment of psychological stress and hazards of new technology are part of the remit. Occupational health risks are reduced by dust control, appropriate waste disposal, use of safe work stations and practices, limiting exposure to harmful substances, and screening for early evidence of occupational disorders.... occupational medicine

Screening Test

a test carried out on a large number of apparently healthy people to separate those who may have a specified disease and could benefit from further testing from those who probably do not. Examples include newborn blood spot screening, cervical screening, and breast screening. The appropriateness of screening depends on the severity and *epidemiology of the disease and the efficacy and availability of treatment. Other factors to be taken into account are the safety, acceptability, cost, *sensitivity, and specificity of the test. No screening test is perfect, and all screening is associated with *false positives and *false negatives. See also genetic screening; UK National Screening.... screening test



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