Appraising a trial for a shared decision — OSCE

Station brief (8–10 minutes)

Help the parents decide whether to start the preventive therapy by appraising the trial honestly and applying it to their child. Address the online '50 percent' figure, the trial's validity, the magnitude and precision of the effect, and its applicability to a four-year-old. Do not invent jurisdiction-specific thresholds or specific survival statistics. [1]

Tasks for the candidate

1. Frame the clinical question in PICO terms and describe how you would judge the trial's validity before its results. [2]
2. Reframe the '50 percent' figure with the absolute baseline, the absolute risk reduction, and the confidence interval. [1] [5]
3. Assess the applicability of adult-trial evidence to a four-year-old and rate the certainty with GRADE. [6] [3]
4. Integrate the evidence with the family's values through shared decision-making, and arrange follow-up. [4] [6]

Expected performance

Must hit. PICO question stated; validity scored with RoB 2 before results, naming randomisation, allocation concealment, blinding, attrition and selective reporting; absolute baseline and absolute risk reduction given alongside the relative figure; confidence interval read for precision and null-crossing; applicability to a four-year-old weighed and certainty rated with GRADE; decision integrated with values; written summary and follow-up arranged. [2] [6]

Merit. Acknowledges the online figure without dismissing the parent; places the single trial in the totality of the evidence; names the indirectness explicitly and downgrades certainty; uses teach-back and a decision aid for the preference-sensitive choice. [3] [4]

Fail. Quotes the 50 percent relative figure alone; reads results before validity; ignores a null-crossing confidence interval; applies adult evidence to a child without weighing applicability; gives no certainty rating, no shared decision, and no follow-up. [5] [6]

Sample candidate structure

“Thank you both for coming in. First, let me be clear about the question we are trying to answer: in a preschool child like yours, does this daily preventive therapy, compared with not taking it, reduce the chance of a serious complication. Before I trust the number you read, I need to check whether the study was fair — was it randomised, were families and assessors blinded, and did everyone stay in the trial. … The '50 percent' you saw is a relative figure, and on its own it looks bigger than it is. Let me show you the absolute numbers: out of 100 children like yours, about this many would have the complication without the medicine, and this many fewer with it. The study was done in adults, and its confidence interval crosses the line of no effect in children, so I would rate the certainty down and be honest that the benefit to a four-year-old is less sure. Let's weigh that together against the side effects and what matters most to your family, and we will check how it goes.” [1] [5] [6]