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Role of meta‐analysis of clinical trials for Alzheimer's disease
Author(s) -
López Arrieta Jesús M.
Publication year - 2002
Publication title -
drug development research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.582
H-Index - 60
eISSN - 1098-2299
pISSN - 0272-4391
DOI - 10.1002/ddr.10092
Subject(s) - dementia , meta analysis , clinical trial , psychological intervention , randomized controlled trial , disease , systematic review , medicine , medline , data extraction , psychology , psychiatry , pathology , political science , law
Alzheimer's disease (AD) is a growing worldwide medical, social, and economic problem. In all countries, both prevalence and incidence of this disorder increase with age. The task of translating scientific clinical research into effective interventions for dementia has proved to be a difficult challenge. Data about the effects of therapeutic interventions come from several sources of evidence, ranging from studies with little potential for systematic bias and minimal random error, such as well‐designed randomized controlled trials, through controlled but nonrandomized cohort and case‐control studies, all the way to opinions based on laboratory evidence or theory. Although clinical trials are widespread in AD, there is increasing recognition that the results of studies do not necessarily apply to the type of patients that are seen by clinicians because of differences in patient characteristics, comorbidities, cotherapies, severity of disease, compliance, local circumstances, and patients preferences, which may differ sufficiently from those in the trial situation to attenuate or change the benefit‐to‐risk ratio. There are several methods to address those issues, like pragmatic trials and n‐of‐1 trials. When data from randomized clinical trials do not provide clear answers from sufficiently similar studies in the magnitude of effect sizes, lack of statistical significance, or identification of subgroups, systematic reviews and meta‐analysis may help to provide a better summary of the data. A major difference between a traditional review and a systematic is the systematic nature in which studies are chosen and appraised. Traditional reviews are written by experts in the field who use differing and often subjective criteria to decide what studies to include and what weight to give them, and hence the conclusions are often very diverse, depending on the reviewer. Publication and selection bias is a major concern of traditional reviews. Systematic reviews and meta‐analysis are being increasingly used in dementia, propelled by the Cochrane Dementia and Cognitive Improvement Group, to make decisions about treatment, management, and care and to guide future research. This narrative review describes the rationale for randomized clinical trials and systematic reviews in dementia, particularly AD. Drug Dev. Res. 56:401–411, 2002. © 2002 Wiley‐Liss, Inc.