SURPASS — 7 things I got wrong before I got it right
Posting this as a discussion rather than a claim: SURPASS — 7 things I got wrong before I got it right.
Compared myself to a trial mean for about six months before realising the trial arm had dietitian contact every fortnight.
Read a press release and the publication three months apart. The hedging in the second one was substantial.
Quoted a figure here confidently, got asked whether it was ITT, went and checked, and it was not. Learned something.
Screenshot none of this. Read the whole thread, including the parts where I am told I am wrong.
best — the order this archive was captured in
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.
The press release said that; the publication says something more hedged. Worth reading both.
The press release said that; the publication says something more hedged.
Agreed. And the interval, not the point estimate, is what the trial actually established.
Agreed.
enzo_ferrari is right about the programme names. They are different populations with different endpoints.
Spent an evening with the appendix tables and found the subgroup detail that the entire thread had been speculating about.
Small fix — that was the cardiovascular outcomes trial, so weight was a secondary endpoint and the population was different.
That is the 68-week readout, not the 72-week one. Different trial, different duration.
Cosigning on discontinuation. It is a result about tolerability and it gets buried every time.
SELECT was cardiovascular outcomes, not weight
Press-release posts get their own flair here. Nothing wrong with them, they are just a different kind of claim.
Correction: SURMOUNT is the obesity programme and SURPASS is the diabetes one. The figure you quoted belongs to the other one.
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.
discontinuation rate is a result, not a footnote
Started keeping the trial identifiers straight in a note file because I kept mixing up two programmes in the same sentence.
Relative risk reduction without the baseline rate is uninterpretable. A large relative reduction on a small absolute risk is a small absolute benefit.
Open-label extensions lose their randomisation. Anybody still enrolled at week 104 is a selected group and the numbers describe that group.
Same. A press release is a claim about a result; the publication is the result.
- 1The press release said that; the publication says something more hedged.…8 comments in this branch · started by u/rulebook_rachael