Clinical Trial: From 4 Different Sources
An investigation concerned with the administration of a medicinal product(s) on the supposition that it (they) may have a positive effect upon patients. The work is carried out under the supervision of a doctor(s) or suitably qualified staff to ascertain beneficial or harmful effects and to report.
Studies which test drug safety and efficacy prior to registration. 1. Phase I: a study in human volunteers to establish safety of a pharmaceutical agent. 2. Phase II: the first investigation of a new drug in patients to determine the preliminary evidence of efficacy and to confirm safety. 3. Phase III: trials designed to determine long term safety, efficacy and cost-effectiveness of a new drug in large numbers of patients.
A controlled research study of the safety and effectiveness of drugs, devices or techniques that occurs in four phases, starting with the enrolment of a small number of people, to the later stages in which thousands of people are involved prior to approval by the licensing authorities (for example, the Food and Drug Administration).
see intervention study.
A framework through which health organizations are accountable for continuously improving the quality of their services and safeguarding high standards of care.... clinical governance
A scienti?c study in which di?erent patients receive a di?erent drug, the same drug at a different dose, or a placebo – with neither the investigators assessing the outcome nor the subjects being treated knowing which of these the latter are receiving. The aim is to remove any hint of bias due to the investigators’ or patients’ preferences or preconceptions. The results are analysed after all the data have been collected and the code has been broken. Trials should have a separate supervising committee, the members of which know the code but do not take part in the study. Their job is to check the results at intervals so they can stop the trial if one arm of treatment is clearly better than another. Otherwise, it would be unethical to continue. (See INTERVENTION STUDY.)... double blind trial
A MEDICAL AUDIT carried out by health professionals.... clinical audit
Clinical means literally ‘belonging to a bed’, but the word is used to denote anything associated with the practical study or observation of sick people – as in clinical medicine, clinical thermometers.... clinical
Professional specialized or therapeutic care that requires ongoing assessment, planning, intervention and evaluation by health care professionals.... clinical care
A diagnosis (e.g. myocardial infarct) or a patient state that may be associated with more than one diagnosis (such as paraplegia) or that may be as yet undiagnosed (such as low back pain).... clinical condition
Services provided to patients (history-taking, physical examination, preventive care, tests, procedures, drugs, advice) or information on clinical condition or on patient state used as a patient outcome.... clinical event
Systematically developed statements which assist clinicians and patients to decide on appropriate treatments for speci?c conditions. The guidelines are attractive to health managers and patients because they are potentially able to reduce variation in clinical practice. This helps to ensure that patients receive the right treatment of an acceptable standard. In England and Wales, the NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE (NICE) is developing national guidelines with advice from health-care professionals and patients to improve clinical e?ectiveness of NHS care. Some doctors have reservations about guidelines because (1) health-care managers might use them primarily to contain costs; (2) in?exibility would discourage clinical innovations; (3) they could encourage litigation by patients. (See also HEALTH CARE COMMISSION; MEDICAL LITIGATION.)... clinical guidelines
An information system that collects, stores and transmits information that is used to support clinical applications (e.g. transmission of laboratory test results, radiology results, prescription drug orders). Electronic medical records are one method by which clinical information systems can be created.... clinical information system
Clinical information, excluding information about treatment and intervention. Clinical information that does not record an intervention is by nature a clinical observation. The observer may be the patient or related person (information about symptoms, family history, occupation or lifestyle) or a health care professional (information about physical signs, measurements, properties observed or diagnoses). While information about the nature of a planned or performed treatment is excluded by the definition, clinical observations may be recorded on the results of a treatment, on progress during the course of a treatment, or on the result of a treatment.... clinical observation
A multidisciplinary set of daily prescriptions and outcome targets for managing the overall care of a specific type of patient, e.g. from pre-admission to post-discharge for patients receiving inpatient care. Clinical pathways are often intended to maintain or improve quality of care and decrease costs for patients in particular diagnosis-related groups.... clinical pathway
An instrument that estimates the extent to which a health care provider delivers clinical services that are appropriate for each patient’s condition; provides them safely, competently and in an appropriate time-frame; and achieves desired outcomes in terms of those aspects of patient health and patient satisfaction that can be affected by clinical services.... clinical performance measure
A systematically developed statement to assist practitioner and patient decisions about appropriate health care for one or more specific clinical circumstances.... clinical practice guideline
A conclusion that an intervention has an effect that is of practical meaning to older persons and health care providers. Even though an intervention is found to have a statistically significant effect, this effect may not be clinically significant. In a trial with a large number of participants, a small difference between treatment and control groups may be statistically significant, but clinically unimportant. In a trial with few participants, an important clinical difference may be observed that does not achieve statistical significance. (A larger trial may be needed to confirm that this is a statistically significant difference).... clinical significance
The physical manifestations of an illness elicited by a doctor when examining a patient – for example, a rash, lump, swelling, fever or altered physical function such as re?exes.... clinical signs
The experiences of a patient as communicated to a doctor, for example, pain, weakness, cough. They may or may not be accompanied by con?rmatory CLINICAL SIGNS.... clinical symptoms
A trial in which each of the groups involved will receive each of the treatments, but in a randomized order: that is, they will start in one arm of the trial, but will deliberately ‘cross over’ to the other arm(s) in turn.... crossover trial
A method of comparing the results between two or more groups of patients intentionally subjected to di?erent methods of treatment – or sometimes of prevention. Those subjects entering the trial have to give their informed permission. They are allocated to their respective groups using random numbers, with one group (controls) receiving no active treatment, instead receiving either PLACEBO or a traditional treatment. Preferably, neither the subject nor the assessor should know which ‘regimen’ is allocated to which subject: this is known as a double-blind trial.... randomised controlled trial
Initially driven by anxiety about the possibility of medical negligence cases, clinical risk management has evolved into the study of IATROGENIC DISEASE. The ?rst priority of risk managers is to ensure that all therapies in medicine are as safe as possible. Allied to this is a recognition that errors may occur even when error-prevention strategies are in place. Lastly, any accidents that occur are analysed, allowing a broader understanding of their cause. Risk management is generally centred on single adverse events. The threat of litigation is taken as an opportunity to expose unsafe conditions of practice and to put pressure on those with the authority to implement change. These might include senior clinicians, hospital management, the purchasing authorities, and even the Secretary of State for Health. Attention is focused on organisational factors rather than on the individuals involved in a speci?c case.... clinical risk management
See “blinding”.... single-blind trial
See “blinding”.... triple-blind trial
Environmental medicine. Treatment of allergies by natural medicines. The science that endeavours to bridge physics and chemistry; including such disciplines as homoeopathy, acupuncture, herbalism, etc. ... clinical ecology
A test on human volunteers of the effectiveness and safety of a drug. A trial can also involve systematic comparison of alternative forms of medical or surgical treatment for a particular disorder. Patients involved in clinical trials have to give their consent, and the trials are approved and supervised by an ethics committee.... trial, clinical
(See EVIDENCE-BASED MEDICINE.) Clinical trials aim to evaluate the relative effects of di?erent health-care interventions. They are based on the idea that there must a fair comparison of the alternatives in order to know which is better. Threats to a fair comparison include the play of chance and bias, both of which can cause people to draw the wrong conclusions about how e?ective a treatment or procedure is.
An appreciation of the need to account for chance and bias has led to development of methods where new treatments are compared to either a PLACEBO or to the standard treatment (or both) in a controlled, randomised clinical trial. ‘Controlled’ means that there is a comparison group of patients not receiving the test intervention, and ‘randomised’ implies that patients have been assigned to one or other treatment group entirely by chance and not because of their doctor’s preference. If possible, trials are ‘double-blind’ – that is, neither the patient nor the investigator knows who is receiving which intervention until after the trial is over. All such trials must follow proper ethical standards with the procedure fully explained to patients and their consent obtained.
The conduct, e?ectiveness and duplication of clinical trials have long been subjects of debate. Apart from occasional discoveries of deliberately fraudulent research (see RESEARCH FRAUD AND MISCONDUCT), the structure of some trials are unsatisfactory, statistical analyses are sometimes disputed and major problems have been the – usually unwitting – duplication of trials and non-publication of some trials, restricting access to their ?ndings. Duplication occurs because no formal international mechanism exists to enable research workers to discover whether a clinical trial they are planning is already underway elsewhere or has been completed but never published, perhaps because the results were negative, or no journal was willing to publish it, or the authors or funding authorities decided not to submit it for publication.
In the mid 1980s a proposal was made for an international register of clinical trials. In 1991 the NHS launched a research and development initiative and, liaising with the COCHRANE COLLABORATION, set out to collect systematically data from published randomised clinical trials. In 1994 the NHS set up a Centre for Reviews and Dissemination which, among other responsibilities, maintains a database of research reviews to provide NHS sta? with relevant information.
These e?orts are hampered by availability of information about trials in progress and unpublished completed trials. With a view to improving accessibility of relevant information, the publishers of Current Science, in 1998, launched an online metaregister of ongoing randomised controlled trials.
Subsequently, in October 1999, the editors of the British Medical Journal and the Lancet argued that the case for an international register of all clinical trials prior to their launch was unanswerable. ‘The public’, they said, ‘has the right to know what research is being funded. Researchers and research funders don’t want to waste resources repeating trials already underway.’ Given the widening recognition of the importance to patients and doctors of the practice of EVIDENCE-BASED MEDICINE, the easy availability of information on planned, ongoing and completed clinical trials is vital. The register was ?nally set up in 2005.... clinical trials
see intervention study.... blind trial
(CCGs) self-governing bodies set up by the Health and Social Care Act 2012, following the abolition of *primary care trusts and *strategic health authorities, to commission most NHS services in England. CCGs are formed of all GP practices within a given geographical area, and all GP practices must belong to a clinical commissioning group. All CCGs have their own constitution and governing body, which (in addition to GPs) must include at least one registered nurse and at least one secondary care specialist doctor. There are currently 195 CCGs in England.... clinical commissioning groups
consideration of the moral issues attendant upon, and questions arising from, clinical practice, as distinct from research. In North America, it is common for hospitals to employ a clinical ethicist or provide a formal clinical ethics consultation service. In the UK, clinical *ethics committees are increasingly common in the NHS.... clinical ethics
see community health.... clinical medical officer
the branch of medicine dealing with the study of actual patients and the diagnosis and treatment of disease at the bedside, as opposed to the study of disease by *pathology or other laboratory work.... clinical medicine
see intervention study.... controlled trial
see intervention study.... cross-over trial
(NCAS) see Practitioner Performance Advice.... national clinical assessment service
see intervention study.... randomized controlled trial
(CGI) rating scales commonly used by clinicians to measure symptom severity and treatment response in treatment studies of patients with psychiatric illnesses. Many researchers consider them to be a good tool to measure the clinical utility or relevance of a given treatment. The Clinical Global Impression–Severity scale (CGI-S) is used to rate the severity of the patient’s symptoms relative to the clinician’s past experience with patients who have the same diagnosis. Scores range from 1 (normal) to 7 (extremely ill). The Clinical Global Impression–Improvement scale (CGI-I) measures change in the patient’s presentation from baseline. Scores range from 1 (very much improved) to 7 (very much worse). A score of 4 indicates no change.... clinical global impression
(OSCE) a type of examination used increasingly in the health sciences (medicine, dentistry, nursing, physiotherapy, pharmacy) to assess clinical skills in examination, communication, medical procedures, and interpretation of results. The examination usually takes the form of a circuit of stations around which each candidate moves after a specified time interval (5–10 minutes) at each station. Stations are a mixture of interactive and noninteractive tasks. Some have an examiner and a simulated patient, either an actor for assessment of communication or history-taking skills or a manikin of a specific part of the body (e.g. to demonstrate how to use an auriscope). Other stations have investigation results with a list of questions that are to be completed on computer-marked examination papers. Each station has a different examiner and the stations are standardized with specific marking criteria, thus enabling fairer comparison with peers.... objective structured clinical examination
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