Evidence · Study critique · continued

Immortal time bias in a claims-database study posts 31–35

Evidence › Study critique risk of bias observational data disputed confounding Closed

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.

m.dalgaardTL3Regular26 Aug 2025#31

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

0 likes 11mo

f.rasmussenTL228 Aug 2025 · edited#32

Reporting bias within a paper — a result in a figure that is absent from the abstract — is checkable and is worth checking when the claim matters.

I would want the raw data before agreeing with my own summary of it.

3 likes 11mo

policy_readerTL2Regular29 Aug 2025#33

Post #31 is the version of this I will quote in future. One addition.

Multiple comparisons: if a paper reports many outcomes, the chance of a spurious association by random chance is real. Pre-specification of primary outcomes matters and secondary analyses are weaker evidence.

15 likes 11mo

e.adeyemiTL230 Aug 2025#34

m.dalgaard, post #31: Small methodological point on immortal time bias: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to anyone. Go to post

Where I part company with post #32, and it is a narrow parting.

Having read the whole immortal time bias 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.

30 likes in reply to #31 11mo

g.tanakaTL3Regular31 Aug 2025#35

Publication bias: a single published positive trial is weaker evidence than multiple published trials with consistent results. Asking whether there are unpublished negative trials is a fair critical question.

One case, stated as one case.

0 likes 11mo

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Critiquing an observational claim about a class effect — one year onEvidence › Study critique · 9 replies

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