Accepted answer
Because two papers on STEP 3 are usually reporting two different estimands from the same randomisation. The treatment-policy estimand asks what happened to everyone assigned, including those who stopped; the trial-product estimand asks what happens if you keep taking it. The second is always the larger number, and both are legitimate answers to different questions. Then there is the analysis population — randomised, treated, or completers — and the handling of missing data, where a last-observation-carried-forward and a multiple imputation can differ by a point or more. Neither paper is wrong. Read the statistical methods section and you will find both figures defined in it.
Start with what the trial was powered for. Everything else in the publication is secondary, exploratory, or a subgroup, and those three words mean three different things.
Confidence intervals matter more than point estimates when two trials disagree. Two studies reporting fifteen and twenty per cent whose intervals overlap heavily have not disagreed about anything.
Open-label extensions are not the same evidence as the randomised phase. Once everyone knows what they are taking, the reported outcomes acquire a bias that no analysis fully removes.
The cardiovascular outcome programme in this class runs to several large randomised trials — LEADER for liraglutide, SUSTAIN-6 and SELECT for semaglutide, REWIND for dulaglutide — and they are the reason the class is discussed as more than a weight intervention.
The caveat is that trial evidence is about licensed product administered under supervision. None of it transfers automatically to research-grade material of unverified content.
Read the protocol and the statistical analysis plan if the result matters to you. Both are usually published alongside.
4Adding a vote because this deserves more of them. – rota_site 3 months ago add a comment