Journal club: indirect comparison between two programmes, defended and attacked — one year on posts 31–51

Posting my indirect comparison numbers with the method attached so they can be discounted properly. Uncontrolled, unblinded, and collected by someone who wanted a particular answer.

A session that ends with a list of what remains unresolved is more useful than one that ends with a verdict. The unresolved list is what feeds the next reading.

If the premise is wrong, everything after it is decoration.

What I want from this indirect comparison thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.

Post #31 and I disagree about the size of the effect, not about the direction.

Indirect comparison is a good example of a question where the honest answer is boring and the interesting answers are unsupported. I would go with boring.

I have been on both sides of the indirect comparison argument in this category within eighteen months, which should tell you how strong the evidence for either side is.

Thank you — that answers what I came here to find out.

The figures usually contain the finding and the text usually contains the interpretation. Separating them for the first twenty minutes is a discipline worth keeping.

I had written a reply contradicting post #35 and deleted it. Here is what survived.

The summary that goes to the digest should say what the paper establishes, what it does not, and one thing the group could not settle. Three paragraphs, no more.

Confirming post #39 from a second method, which matters more than confirming it from a second person.

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.

That is the practical version. The rigorous version is longer and says the same thing.

STEP 1 (N Engl J Med 2021): The pivotal obesity trial for semaglutide and the reference point for most subsequent comparison. Mean weight reduction was substantially larger than anything previously achieved pharmacologically.

Having read the whole indirect comparison thread before replying: the question in the first post has not actually been answered yet, and three of us have answered a nearby one instead.

Post #40 is right about the mechanism and I think understates the practical bit.

Where the group cannot agree, record the disagreement rather than resolving it by seniority. The recorded disagreement is more honest and more useful later.

Coming back to post #42, because the follow-up matters more than the original answer.

Small methodological point on indirect comparison: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to anyone.