Paeds Cases · professional-practice-and-evidence
Appraising design and bias at the bedside — OSCE
OSCE on identifying study design, assessing bias, and judging applicability of evidence to a child and family.
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Study tools
Target exams
MRCPCH ClinicalRACP DCERCPSC Pediatrics
Prompt
Parents of a 7-year-old with a chronic illness have read online that a new therapy dramatically improves outcomes, based on a randomised trial reporting a large benefit; the trial's methods are vague about allocation, 25 percent of participants were lost to follow-up, and the trial was conducted in adults; the parents want to know whether their child should start it.
Station brief (8–10 minutes)
Help the parents decide whether to start the new therapy by appraising the trial's design honestly and judging its applicability to their seven-year-old. Address the vague allocation and the 25 percent loss to follow-up as sources of bias, weigh the fact that the trial was conducted in adults, and integrate the evidence with the family's values. Do not invent jurisdiction-specific thresholds or specific outcome statistics. [1]
References5ShowHide
- [1]Sackett DL, Rosenberg WM, Gray JA, Haynes RB, Richardson WS Evidence based medicine: what it is and what it isn't BMJ, 1996.PMID 8555924
- [2]Grimes DA, Schulz KF An overview of clinical research: the lay of the land Lancet, 2002.PMID 11809203
- [3]Schulz KF, Chalmers I, Hayes RJ, Altman DG Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials JAMA, 1995.PMID 7823387
- [4]Rothwell PM External validity of randomised controlled trials: to whom do the results of this trial apply? Lancet, 2005.PMID 15639683
- [5]Sterne JAC, Savović J, Page MJ, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials BMJ, 2019.PMID 31462531