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Frank Harrell's avatar

Sanjay this is well written and points out the continuing serious error made by NEJM and most other journals: use phrases like "did not improve" in the conclusion. That is inappropriate as you so well discussed. More honest phrases would include "the money was spent" or "at the current sample size there is insufficient evidence amassed to counter the supposition of no difference in outcomes between strategies." A Bayesian analysis would give an accurate and succinct result: "The probability of clinical similarity of outcomes for the two strategies is 0.25." [One could compute the actual probability. 0.25 is a rough guess.]

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Harold Lehmann's avatar

Pragmatic trials should be preceded by an EHR query, and not rely on priors from the literature, alone. An argument could be made that a retrospective in silico simulated trial should precede a prospective (more expensive) trial. However, I am not sure if funders are enthusiastic about "delaying" a prospective study in this way. And then the prior should be skeptical (as per Spiegelhalter). Of course, a more explicit Bayesian design is not a bad idea.

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