Journal club: SURMOUNT-1, read without the press release posts 91–120
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
This follows post #90 rather than contradicting it.
An hour is enough for one paper read properly and not enough for two read partly. The temptation is always to add the second.
That matches what I have seen, for whatever a single anecdote is worth.
The baseline characteristics table is the single most useful page for the questions that get asked here, because it tells you who the result applies to.
The general answer and the answer for your case may diverge here.
My understanding of SURMOUNT-1 is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
On post #96 — agreed on the reasoning, with one qualification.
People arriving without having read it should be welcome and should say so, because a question from someone who has not read it frequently exposes an assumption everyone else made.
Answering the question post #96 raises rather than the one it answers.
SURMOUNT-1 has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
Taking post #100 at face value and following it one step further.
The most common failure mode is spending fifty minutes on the effect size and ten on the population. Reversing that ratio would improve most sessions.
Post #98 and I disagree about the size of the effect, not about the direction.
Two questions I would want answered before drawing anything from the SURMOUNT-1 data above: how were the cases selected, and what happened to the ones that dropped out.
On SURMOUNT-1 the community has more anecdote than the confidence in this thread implies, and I include my own contribution in that.
Assigning the statistics to somebody who will read the analysis plan rather than the results section is worth doing in advance. It is the part that gets skipped by default.
The honest answer is that it depends, and here is what it depends on.
SURMOUNT-1 (N Engl J Med 2022): Tirzepatide obesity trial. The largest mean weight reduction for a pharmacological intervention at publication. Read the categorical thresholds carefully — they can exaggerate separation.
That has held every time I have looked, which is not the same as always.
Reading order that works for these sessions: registry entry, methods, baseline table, primary result, then abstract last. Reading the abstract first anchors everything that follows.
That holds for the case as described. Change the assumptions and it may not.
I have been on both sides of the SURMOUNT-1 argument in this category within eighteen months, which should tell you how strong the evidence for either side is.
Where the group cannot agree, record the disagreement rather than resolving it by seniority. The recorded disagreement is more honest and more useful later.
The evidence for this is thinner than the way I have phrased it suggests.
Where I part company with post #109, and it is a narrow parting.
If you are new and reading this thread for the answer to SURMOUNT-1: the answer is conditional, the conditions are in the third reply, and the rest of the thread is worth skipping.
Collapsed as off-topic by two members at trust level 3 or above
Post #109 is the version of this I will quote in future. One addition.
I have three months of notes on SURMOUNT-1 and the honest summary is that the trend is real and the week-to-week numbers are noise. I nearly drew the opposite conclusion from the first fortnight.
SELECT (N Engl J Med 2023): Semaglutide cardiovascular outcomes without diabetes. The first outcome trial in people without diabetes, which decoupled the cardiovascular argument from glucose control. Read the absolute numbers, not just the relative reduction.
The claim is narrower than it sounds, and deliberately so.
The reason SURMOUNT-1 is hard to answer is that the obvious measurement and the relevant quantity are not the same thing, and substituting one for the other is silent.
Post #113 put the caveat in the right place and I want to underline it.
Worth stating the null on SURMOUNT-1 before we explain it: the observation may be nothing. That possibility deserves a sentence and usually does not get one.
Nothing to add on the substance. Thank you for taking the question at face value.
An hour is enough for one paper read properly and not enough for two read partly. The temptation is always to add the second.
Adding it in case it saves somebody the afternoon it cost me.
Session format: read the paper before posting. The discussion is much better when everyone has. Start with the estimand and population, then methods, then results, then limitations. That order makes critique coherent.
The general case is well covered; this is the awkward specific one.