Anaes SAQs · Measurement & monitoring physics
Study design and the hierarchy of evidence
Primary - hierarchy of evidence pyramid; case-control (retrospective, odds ratio), cohort (prospective, relative risk), cross-sectional (prevalence, no causality); RCT is the gold standard for therapy because randomisation distributes known and unknown confounders equally; allocation concealment, blinding and intention-to-treat analysis minimise selection, performance, detection and attrition bias; systematic reviews and meta-analyses (PRISMA) pool the evidence; GRADE rates quality high, moderate, low or very low.
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Describe the hierarchy of evidence in clinical research. For each level, give the study design, its principal measure of effect, and its main source of bias. Explain why the randomised controlled trial is the gold standard for evaluating therapy, and outline the features of trial design that minimise bias. Outline how the GRADE framework rates the quality of evidence.[1]
References4ShowHide
- [1]Grimes DA, et al. An overview of clinical research: the lay of the land. Lancet, 2002.PMID 11809203
- [2]Schulz KF, et al. CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMJ, 2010.PMID 20332509
- [3]Moher D, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med, 2009.PMID 19621072
- [4]Guyatt GH, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ, 2008.PMID 18436948