Evidence · Trials

Sample size calculations, read backwards from the published number

Evidence › Trials intention to treat surrogate endpoints randomised trial

IRenaudinTL2Member4 Sep 2025#1

Sample size calculations, read backwards from the published number Writing it up because I had to work it out twice and would rather nobody else did.

Asking about sample size calculations directly, because I have read four threads on it and each answered a slightly different question.

The version I want answered is the narrow one: given the method stated below, is the result within what anyone else has seen? I am not asking what it means yet.

Method, numbers and the two assumptions I am aware of making are below. If the assumptions are wrong that is more useful to me than agreement.

2 likes 11mo

ambient_reviewTL3Regular2 Dec 2025#2

Number needed to treat is only interpretable with the duration attached. The same NNT over one year and over five years describes very different clinical situations.

The evidence for this is thinner than the way I have phrased it suggests.

0 likes 8mo

mi.almeidaTL23 Feb 2026#3

Discontinuation handling is the methodological detail that most changes a result and gets the least attention. Read how missing data was imputed before reading the effect size.

16 likes 6mo

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Reading a supplementary appendix and finding the interesting partEvidence › Trials · 92 replies

Promoted into the documentation commons. The content of this topic is maintained at STEP 4 — trial digest, with named maintainers and a review date. The promotion was discussed in doc review. Corrections are best raised against the document, which is the version that gets kept current.

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