Incidence rate Health Dictionary

The number of cases of disease, infection or some other event having their onset during a prescribed period of time. It is often expressed as a rate (for example, the incidence of cardiovascular disease per 1000 population aged 65-74 years during a specified year). Incidence is a measure of morbidity or other events that occur within a specified period of time. See also “prevalence”.... incidence

In 2003, 695,500 live births were registered in the United Kingdom; 38 per cent occurred outside marriage. Overall, total fertility is falling slowly. The number of births per 1,000 women aged over 40 years has been rising, and in 1999 was 8.9 per cent. In Great Britain in 2003, 193,817 legal abortions were performed under the Abortion Act 1967.... birth rate

The proportion of deaths in a specified population. The death rate is calculated by dividing the number of deaths in a population in a year by the midyear resident population. Death rates are often expressed as the number of deaths per 100 000 persons. The rate may be restricted to deaths in specific age, race, sex, or geographic groups or deaths from specific causes of death (specific rate), or it may be related to the entire population (crude rate).... death rate

See “death rate”.... mortality rate

The number of fatal cases of specific disease, divided by total number of known cases and it is usually expressed as percent. Case fatality is one index of disease severity and is of more interest in acute than in chronic disease.... case fatality rate

See ESR.... erythrocyte sedimentation rate

The number of live births that occur in a year for every 1,000 women of childbearing age (this is usually taken as 15–44 years of age). The fertility rate in the UK (all ages) was 54.9 in 2002 (UK Health Statistics, 2001 edition, The Stationery O?ce).... fertility 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

See ESR.... sedimentation rate

The ratio of the number of new cases of the disease and the amount of population-time of follow-up (e.g. person-year) of the disease-free population.... average incidence density

The proportion of number of newly detected cases that developed during follow-up by the number of disease-free subjects at the start of follow-up.... cumulative incidence

Each of the two KIDNEYS ?lters a large volume of blood – 25 per cent of cardiac output, or around 1,300 ml – through its two million glomeruli (see GLOMERULUS) every minute. The glomeruli ?lter out cell, protein, and fat-free ?uid which, after reabsorption of certain chemicals, is excreted as urine. The rate of this ultra?ltration process, which in health is remarkably constant, is called the glomerular ?ltration rate (GFR). Each day nearly 180 litres of water plus some small molecular-weight constituents of blood are ?ltrated. The GFR is thus an indicator of kidney function. The most widely used measurement is CREATININE clearance and this is assessed by measuring the amount of creatinine in a 24-hour sample of urine and the amount of creatinine in the plasma; a formula is applied that gives the GFR.... glomerular filtration rate (gfr)

The reporting and tracking of adverse incidents by care providers.... incidence monitoring and reporting

The number of deaths of infants under one year of age. The IMR in any given year is calculated as the number of deaths in the ?rst year of life in proportion to every 1,000 registered live births in that year. Along with PERINATAL MORTALITY, it is accepted as one of the most important criteria for assessing the health of the community and the standard of the social conditions of a country.

The improvement in the infant mortality rate has occurred mainly in the period from the second month of life. There has been much less improvement in the neonatal mortality rate – that is, the number of infants dying during the ?rst four weeks of life, expressed as a proportion of every 1,000 live births. During the ?rst week of life the main causes of death are asphyxia, prematurity, birth injuries and congenital abnormalities. After the ?rst week the main cause of death is infection.

Social conditions also play an important role in infant mortality. In England and Wales the infant mortality rate in 1930–32 was: Social Class I (professional), 32·7; Social Class III (skilled workers), 57·6; Social Class V (unskilled workers), 77·1. Many factors come into play in producing these social variations, but overcrowding is undoubtedly one of the most important.

1838–9 146 1950–52 30 1851–60 154 1960–62 22 1900–02 142 1970–72 18 1910–12 110 1980–82 12 1920–22 82 1990–92 7 1930–32 67 1996 6·2 1940–42 59 1999 5.8 2000 5.6

It is thus evident that for a reduction of the infant mortality rate to the minimum ?gure, the following conditions must be met. Mothers and potential mothers must be housed adequately in healthy surroundings, particularly with regard to safe water supplies and sewage disposal. The pregnant and nursing mother must be ensured an adequate diet. E?ective antenatal supervision must be available to every mother, as well as skilled supervision during labour (see PREGNANCY AND LABOUR). The newborn infant must be adequately nursed and fed and mothers encouraged to breast feed. Environmental and public-health measures must be taken to ensure adequate housing, a clean milk supply and full availability of medical care including such protective measures as IMMUNISATION against diphtheria, measles, poliomyelitis and whooping-cough. (See also PERINATAL MORTALITY.)... infant mortality rate (imr)

A measure of the use of facilities, most often inpatient health facility use, determined by dividing the number of patient days by the number of bed days (or places) available, on average, per unit of time, multiplied by 100.... occupancy rate

The proportion of female mosquitoes that have laid eggs at least once. Use for age-grading a mosquito population.... parous rate

quotient using as the numerator, the number of persons sick or portraying a certain condition, in a stated population, at a particular time, regardless of when that illness or condition began, and as the denominator, the number of persons in the population in which they occurred.... prevalence rate

A measure of the relative contribution to total mortality by a specific cause and these are expressed as number of deaths assigned to the state cause in a calendar year per 1000 total deaths in that year.... proportional mortality rate (pmr)

Review by a government or private agency of a hospital’s or health service’s budget and financial data, performed for the purpose of determining if the rates are reasonable of the rates and evaluating proposed rate increases.... rate review

A method of paying health care providers in which the government establishes payment rates for all payers for various categories of health service.... rate setting

The proportion of a hospital’s patients (or a subset, such as those with asthma) who are readmitted to the hospital following discharge with the same diagnosis. It is used as a performance measure where a higher rate indicates lower quality of care.... readmission rate

The number of completed or returned survey instruments (questionnaires, interviews, etc) divided by the total number of persons who would have been surveyed if all had participated. Usually expressed as a percentage.... response rate

Health status is usually obtained from survey data by asking the respondent if his/her health is excellent, very good, good, fair or poor (or similar questions).... self-rated health status / perceived health status

The proportion of female mosquitoes that have sporozoites in the salivary gland.... sporozoite rate

the number of people from a specified population with a specified disease or condition admitted to hospitals in a given geographical area over a specified time period.... admission rate

the total number of events (e.g. cases of lung cancer) expressed as a rate per 1000 population. When factors such as age structure or sex of populations can significantly affect the rates (as in *mortality or *morbidity rates) it is more meaningful to compare age/sex specific rates using one or more age groups of a designated sex (e.g. lung cancer in males aged 55–64 years). More complex calculations, which take account of the age and sex structure of a population as a whole, can produce *standardized rates and *standardized mortality ratios (SMR).... crude rate

(GFR) the rate at which substances are filtered from the blood of the glomeruli into the Bowman’s capsules of the *nephrons. It is calculated by measuring the *clearance of specific substances (e.g. creatinine) and is an index of renal function. See eGFR.... glomerular filtration rate

see pulse.... heart rate

see case fatality rate.... hospital fatality rate

see infant mortality rate.... neonatal mortality rate

(PEFR) the maximum rate at which a person can forcibly expel air from the lungs at any time, expressed usually in litres per minute (occasionally in litres per second). A low value can help diagnose asthma in the correct clinical context, and differences between the morning and evening values can also be a feature of poor control of asthma. There is a place for PEFR in the monitoring of acute exacerbations of chronic pulmonary obstructive disease (COPD) but not in the diagnosis of COPD.... peak expiratory flow rate

(PNM) the total number of babies born dead after 24 weeks gestation (*stillbirths) and of live-born babies that die in the first week of life, regardless of gestational age at birth (early neonatal deaths), per 1000 live births and stillbirths. See infant mortality rate. See also confidential enquiries.... perinatal mortality rate

see fertility rate.... reproduction rate

(RR) breathing rate: the number of breaths per minute. Normally between 6 and 12, it increases after exercise and in cases of *respiratory distress and decreases after head injury and opioid overdosage.... respiratory rate

(IMR) the number of deaths of children under one year of age per 1000 live births in a given year. Included in the IMR are the neonatal mortality rate (calculated from deaths occurring in the first four weeks of life) and postneonatal mortality rate (from deaths occurring from four weeks). Neonatal deaths are further subdivided into early (first week) and late (second, third, and fourth weeks). In prosperous countries neonatal deaths account for about two-thirds of infant mortalities, the majority being in the first week (in the UK the major cause is prematurity and related problems). The IMR is usually regarded more as a measure of social affluence than a measure of the quality of antenatal and/or obstetric care; the latter is more truly reflected in the *perinatal mortality rate.... infant mortality rate

the number of deaths due to complications of pregnancy, childbirth, and the puerperium per 100,000 live births (see also stillbirth). In 1952 concern about maternal mortality resulted in Britain in the setting up of a triennial *confidential enquiry into every such death to identify any shortfall in resources or care. The first triennial report was published in 1985. Since 2014 reports have been produced annually by MBRRACE-UK (Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries Across the UK). Levels of *maternal deaths are currently low: a report published in 2017 (covering 2013–15) counted 202 obstetric-related deaths (8.76 per 100,000 live births). Thromboembolism was the commonest direct cause of death (30 deaths, 1.13 per 100,000 live births), while heart disease was the commonest indirect cause of death (54 deaths, 2.34 per 100,000 live births).... maternal mortality rate

rates used to summarize the *morbidity or *mortality experience of a population. Age-specific rates and population structures from a study population and a reference or *standard population are used to produce a weighted average. Standardized rates can be used to compare the health experience of populations with different structures. Direct standardization requires application of age-specific rates from a study population to a reference population structure (e.g. the European standard population) to produce a (directly) standardized rate. Indirect standardization requires application of age-specific rates from a standard population (e.g. England and Wales) to a study population structure to produce an expected morbidity or mortality rate. Compare crude rate.... standardized rates