SURPASS — 6 things I got wrong before I got it right
SURPASS — 6 things I got wrong before I got it right. It is the sort of thing everyone half-believes and nobody writes down.
Spent an evening with the appendix tables and found the subgroup detail that the entire thread had been speculating about.
Quoted a figure here confidently, got asked whether it was ITT, went and checked, and it was not. Learned something.
Read a press release and the publication three months apart. The hedging in the second one was substantial.
If two or three other people have done the same thing we might actually learn something. Alone it is an anecdote.
best — the order this archive was captured in
The registered protocol is public. Comparing the registered primary endpoint with the reported one is a two-minute check and it is how outcome switching gets caught.
Cardiovascular outcome trials are powered for events, not for weight, and are typically run in a different population with different inclusion criteria. Reading a weight number out of one is reading a secondary endpoint.
Compared myself to a trial mean for about six months before realising the trial arm had dietitian contact every fortnight.
Left up and flaired Trial Data. The publication is linked rather than the coverage, which is what we ask for.
Agreed. Half the arguments on this site are two people quoting different trials at each other without noticing.
Argued for a week about a result and then read the limitations section, which conceded most of my opponent’s point.
That is a relative risk reduction. Quoting it without the absolute numbers overstates the case considerably.
registry entry, protocol, publication — three different documents
Correcting myself upthread: I gave the completer figure and labelled it intention-to-treat.
Small fix — that was the cardiovascular outcomes trial, so weight was a secondary endpoint and the population was different.
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.
Push back: an open-label extension tells you about the people who stayed. That is a different question.
How long was the randomised phase before any extension?
STEP is semaglutide obesity, SURMOUNT is tirzepatide obesity, they are not interchangeable
Yes. The appendix tables are where the subgroup and the adverse event detail actually live.
the confidence interval is the finding, the point estimate is the headline
Is that intention-to-treat or completers?
a press release is not a publication
Careful with that mean. The distribution around it was wide enough that it describes very few individual participants.
Not convinced. Cross-trial comparison between two programmes with different populations and designs is not a comparison.
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.
Do you have the publication or the press release?
- 1That is a relative risk reduction. Quoting it without the absolute numbers…7 comments in this branch · started by u/arne_ilunga