Numbers first: REDEFINE-1 · hair thinning.
This is presented as though it settles something, and I am not convinced it does.
I have two documents that appear to disagree, which is what prompted this.
What is the correct interpretation, and what is the common misreading?
The REDEFINE-1 placebo arm is the only thing that makes its treatment arm interpretable, and it is the row nobody quotes. Symptoms reported under placebo in these programmes are not rare, because the population is being asked about them weekly and would have had some of them regardless. The attributable figure is the treated rate minus the placebo rate, and that difference is routinely a fraction of the headline. Two cautions on the subtraction: the arms must have been assessed the same way, and a discontinuation for an event removes that participant from later time points in both arms, which flatters whichever arm loses more people.
Answer first: read the primary endpoint, the comparator and the population before you read the effect size. Almost every argument on this site about a trial is really an argument about one of those three.
Trial populations are selected. Exclusion criteria in this class routinely remove people with significant renal impairment, prior pancreatitis and unstable psychiatric illness, which is exactly the population the results are then quoted for.
The part that matters: duration decides what can be seen. A 68-week trial can measure weight and glycaemia; it cannot measure anything whose event rate is one per cent per year without enrolling tens of thousands.
The cardiovascular outcome programme in this class runs to several large randomised trials — LEADER for liraglutide, SUSTAIN-6 and SELECT for semaglutide, REWIND for dulaglutide — and they are the reason the class is discussed as more than a weight intervention.
Be careful about generalising from a trial population to yourself. The exclusion criteria are usually the most informative page in the supplement.
If a claim cannot be traced to a named trial with a named endpoint, treat it as a claim rather than as evidence.
Analytical standards and reagents with traceable certificates. Every quantitative result you read inherits the accuracy of the standard behind it.
Shop standardsA trial establishes what happened to a defined group under a defined protocol. Extending it beyond that group is inference, and inference is allowed as long as it is labelled.
Open-label extensions are not the same evidence as the randomised phase. Once everyone knows what they are taking, the reported outcomes acquire a bias that no analysis fully removes.
Non-inferiority and superiority designs are not interchangeable. A non-inferiority result says the new agent is not meaningfully worse against a pre-specified margin — it does not say it is as good, and it certainly does not say it is better.
One qualification: absence of a signal in a trial of this size is not evidence of absence for a rare event. It is evidence that the event is rarer than the trial could detect.
The short version: check the endpoint, check the comparator, check who was excluded, then look at the number.
This is answerable from the published record, but only if you take the placebo arm seriously rather than reading the active arm alone.
Intention-to-treat and per-protocol analyses answer different questions. ITT asks what happens if you offer the treatment; per-protocol asks what happens if it is taken as directed. The gap between the two is a measure of how tolerable the protocol was.
In practice, a composite endpoint is only as informative as its least serious component. Where a cardiovascular composite combines death, infarction and stroke, ask which component moved, because they are not interchangeable outcomes.
The caveat is that trial evidence is about licensed product administered under supervision. None of it transfers automatically to research-grade material of unverified content.
Read the protocol and the statistical analysis plan if the result matters to you. Both are usually published alongside.
Ask PeptideStack is a static archive. Posting is closed, but the norms are worth stating: answer the question that was asked, show your working, cite the trial or the certificate, and say plainly where the evidence runs out.