ContextThere is substantial debate about whether the results of nonrandomized studies are
consistent with the results of randomized controlled trials on the same topic. ObjectivesTo …

Evidence-based health care is becoming increasingly popular and, at least in some settings,
is being used to assist in the creation of health care policy. 1 Meta-analyses are a key …

OBJECTIVES: To consider methods and related evidence for evaluating bias in non-
randomised intervention studies. DATA SOURCES: Systematic reviews and methodological …

When little or no data directly comparing two treatments are available, investigators often
rely on indirect comparisons from studies testing the treatments against a control or placebo …

OBJECTIVE: To assess whether nominally statistically significant effects in meta-analyses of
clinical trials are true and whether their magnitude is inflated. STUDY DESIGN AND …

Worldwide, hundreds of thousands of premature deaths a year could be avoided by seeking
large-scale randomized evidence about various widely practicable treatments for the …

Context.—The extent of concordance between meta-analyses and large trials on the same
topic has been investigated with different protocols. Inconsistent conclusions created …

Evidence from randomized controlled clinical trials is widely accepted as the only sound
basis for assessing the efficacy of new medical treatments. Statistical methods play a key …

The Magic of Randomization Nonrandomized observational analyses have been promoted
as alternatives to randomized clinical trials. However, randomization ensures balance …

Randomized clinical trials have become the accepted scientific standard for evaluating
therapeutic efficacy. Contradictory results from multiple randomized clinical trials on the …