reading SURMOUNT threads from 2024 and half of it aged badly
reading SURMOUNT threads from 2024 and half of it aged badly. Making the case below, and I expect to lose some of it in the comments.
Quoted a figure here confidently, got asked whether it was ITT, went and checked, and it was not. Learned something.
Spent an evening with the appendix tables and found the subgroup detail that the entire thread had been speculating about.
Discontinuation rates are a tolerability result. A trial with a strong efficacy number and heavy discontinuation is telling you two things and people only quote one.
Corrections welcome, especially the pedantic ones. Pedantry is how this board earns its reputation.
best — the order this archive was captured in
How to read one of these papers in fifteen minutes, in the order that actually helps.
Start with the registered protocol and check the primary endpoint against what is reported. Then the methods: who was included, what the comparator was, how long the randomised phase ran. Then the discontinuation numbers, which are a tolerability result and are usually in a supplementary table.
Only then the efficacy figure, and read the interval rather than the point estimate. Finish with the limitations section, which is where the authors say what they actually think.
Fifteen minutes, and you will know more than any thread summarising it.
Not convinced. Cross-trial comparison between two programmes with different populations and designs is not a comparison.
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Agreed on comparators. "Superior" means nothing until you know superior to what and at what dose.
open-label extensions are not the same evidence as the randomised phase
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.
Started keeping the trial identifiers straight in a note file because I kept mixing up two programmes in the same sentence.
The press release said that; the publication says something more hedged. Worth reading both.
discontinuation rate is a result, not a footnote
SELECT was cardiovascular outcomes, not weight
Right — trial participants get structured support. Comparing yourself to a trial mean is comparing across two different interventions.
Disagree — that figure is from the diabetes programme and you are quoting it as an obesity endpoint.
Went looking for the registered protocol to see whether the endpoint had changed. It had not, which was reassuring and worth checking.
Read a press release and the publication three months apart. The hedging in the second one was substantial.
Why comparing across trials almost never works, with the specific failure modes.
Different populations: an obesity programme and a diabetes programme enrol different people with different baseline characteristics. Different endpoints: body weight change, glycaemic control and cardiovascular events are not convertible. Different durations: 68 weeks and 72 weeks are not the same, and the curves have not flattened by either.
Different analysis populations: one paper reports intention-to-treat, another emphasises completers. Different support: some trial designs include structured lifestyle contact that no member of this board receives.
Stack those and the "X beats Y" tables that circulate here are comparing five things at once and attributing the difference to the molecule.
the appendix is where the interesting tables live
STEP is semaglutide obesity, SURMOUNT is tirzepatide obesity, they are not interchangeable
Yes — the interval is the finding. A point estimate with a wide interval is a hypothesis in a nice font.
check who the comparator was before you compare anything
a press release is not a publication
That is a relative risk reduction. Quoting it without the absolute numbers overstates the case considerably.
Agreed. Half the arguments on this site are two people quoting different trials at each other without noticing.
Compared myself to a trial mean for about six months before realising the trial arm had dietitian contact every fortnight.
Added the trial identifier to the title so this thread is findable in two years.
Small fix — that was the cardiovascular outcomes trial, so weight was a secondary endpoint and the population was different.
a mean is not a promise
a mean is not a promise
Disagreeing with this line: that is a relative reduction and the absolute numbers are considerably less dramatic.
This. Intention-to-treat versus completer analysis routinely moves the headline by several points.
Argued for a week about a result and then read the limitations section, which conceded most of my opponent’s point.
How long was the randomised phase before any extension?
- 1How to read one of these papers in fifteen minutes, in the order that…8 comments in this branch · started by u/first_hundred
- 2Compared myself to a trial mean for about six months before realising the…8 comments in this branch · started by u/ewan_tulloch