SURPASS — 11 things I got wrong before I got it right
SURPASS — 11 things I got wrong before I got it right. It is the sort of thing everyone half-believes and nobody writes down. A confidence interval is the range of effects compatible with the data. Two trials with overlapping intervals have not disagreed, whatever their point estimates look like next to each other.…
intention to treat versus completers changes the number substantially
Careful with that mean. The distribution around it was wide enough that it describes very few individual participants.
Right — trial participants get structured support. Comparing yourself to a trial mean is comparing across two different interventions.
phase 2 finds a dose, phase 3 measures the effect
Do you have the publication or the press release?
Small fix — that was the cardiovascular outcomes trial, so weight was a secondary endpoint and the population was different.
Relative risk reduction without the baseline rate is uninterpretable. A large relative reduction on a small absolute risk is a small absolute benefit.
Correction: SURMOUNT is the obesity programme and SURPASS is the diabetes one. The figure you quoted belongs to the other one.
Intention-to-treat analyses everybody randomised regardless of what they did afterwards. Completer analyses only those who finished. The second is systematically more flattering and both are legitimate if labelled.