clinical trial

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Related to Controlled trials: Randomized clinical trial


 [tri´al, trīl]
a test or experiment.
clinical trial an experiment performed on human beings in order to evaluate the comparative efficacy of two or more therapies. See also single blind, double blind, and triple blind.

clinical trial

a controlled experiment involving a defined set of human subjects, having a clinical event as an outcome measure, and intended to yield scientifically valid information about the efficacy or safety of a drug, vaccine, diagnostic test, surgical procedure, or other form of medical intervention.

Four phases of clinical trial are distinguished. Phase I trials usually involve fewer than 100 healthy volunteers who are exposed to a new drug or procedure. Such studies seek to establish optimal dosage and route of administration and to detect adverse reactions. Phase II trials generally involve 200-500 volunteers randomly assigned to control and study groups. These are pilot efficacy studies, with emphasis on immunogenicity in the case of vaccines, and on relative efficacy and safety in the case of drugs, procedures, and devices. Phase III trials, often multicenter, involve thousands of volunteers, randomly assigned to control and study groups. The aim is to generate statistically relevant data. Phase IV trials are conducted after a national drug registration authority (in the U.S., the Food and Drug Administration) has approved an agent for distribution or sale. They may explore specific pharmacologic effects, adverse reactions, or long-term effects.

clinical trial

A research study using consenting human subjects that tests the effectiveness and safety of a treatment, a diagnostic tool, or a prophylactic intervention.

clinical trial

A research study involving human subjects designed to answer specific questions about the safety and efficacy of a biomedical intervention (drug, treatment, device), or new ways of using a known drug, treatment or device.

clinical trial

Clinical medical trial, clinical research trial Research A controlled study involving human subjects, designed to evaluate prospectively the safety and effectiveness of new drugs or devices or behavioral interventions. See Drug discovery, IND, Phase I, II, and III studies.

clin·i·cal trial

(klini-kăl trīăl)
A controlled experiment involving a defined set of human subjects, having a clinical event as an outcome measure, and intended to yield scientifically valid information about the efficacy or safety of a drug, vaccine, diagnostic test, surgical procedure, or other form of medical intervention.

clinical trial

a scientifically controlled study under specific conditions, to test, for example, the effectiveness of a drug/ treatment.

Clinical trial

All new drugs undergo clinical trials before approval. Clinical trials are carefully conducted tests in which effectiveness and side effects are studied, with the placebo effect eliminated.

trial, randomized controlled (RCT) 

An experimental design used for testing the effectiveness of a new medication or a new therapeutic procedure. Individuals are assigned randomly to a treatment group (experimental therapy) and a control group (placebo or standard therapy) and the outcomes are compared. The trial is strengthened by 'blinding' or masking (single-blind, double-blind or triple-blind study) and cross-over design. RCT is the most accepted scientific method of determining the benefit of a drug or a therapeutic procedure. It represents the best evidence available, which is integrated into the final decision about the management of a condition by healthcare practitioners in what is called evidence-based healthcare. Syn. randomized clinical trial. See sampling; significance; study.

clinical trial,

n a trial based upon the scientific method in which a control group and a test group are compared over time in order to study a single, differing factor.
References in periodicals archive ?
CBT produces relief for youth with depression in about 6 months, but the rate of change in actual practice is slower than in randomized controlled trials, he said.
Of the two meta-analyses that reported funding sources of the included randomized, controlled trials, one listed funding sources in a table footnote, and the other in the "Characteristics of Studies" table that followed the main document and references, according to the researchers.
A 1995 metaanalysis of all nine randomized controlled trials found that the monitored patients had higher rates of C-section, forceps, or vacuum use for fetal distress; higher overall C-section rates; and fewer neonatal deaths due to hypoxia.
the ENDEAVOR II randomized, controlled trial comparing the performance of the Endeavor drug-eluting stent to the Medtronic Driver[R] bare metal stent
The article states that "two randomized controlled trials have suggested that statins slow cognitive decline in mild to moderate Alzheimer's disease", and "large-scale randomized controlled trials of simvastatin and atorvastatin for mild to moderate Alzheimer's disease are underway, which may provide more conclusive results than earlier studies.
Effect of probiotics on inducing remission and maintaining therapy in ulcerative colitis, Crohn's disease and pouchitis: Meta-analysis of randomized controlled trials, Inflamm Bowel Dis.
Five case-control studies, eight cohort studies, and two randomized controlled trials with a total of nearly 14,000 CRC cases in 841,000 diabetes patients were included in the meta-analysis.
The authors of this recent paper compared the safety and efficacy of antibiotic treatment versus appendicectomy for the primary treatment of uncomplicated acute appendicitis using a meta-analysis of randomised controlled trials.
A mecta-analysis of randomized controlled trials was performed to determine the benefit of aspirin in preventing the onset of both cardiovascular disease (CVD) and nonvascular events.
Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials.
It will take larger-scale, controlled trials to determine whether this expensive, potentially risky procedure is superior to other approved treatment options.
The researchers identified 146 prospective cohort studies that looked back on the habits of a particular group of individuals, and 43 randomised controlled trials wherein participants were randomly assigned to a dietary intervention or a control group.

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