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Evidence · Study critique · continued

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

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

MD
m.dalgaardTL3Regular26 Aug 2025#31

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.

0 likes 11mo
FR
f.rasmussenTL2 Moderator28 Aug 2025 · edited#32

Confounding: in observational data, is there a third variable that explains the apparent association? In randomised data, randomisation should balance unknown confounders, though known confounders can be adjusted for.

3 likes 11mo
PR
policy_readerTL2Regular29 Aug 2025#33

This follows post #30 rather than contradicting it.

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 Asking whether there are unpublished negative trials is a fair critical question.

15 likes 11mo
EA
e.adeyemiTL2 Moderator30 Aug 2025#34
m.dalgaard, post #31: 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. Go to post

I read post #32 twice before replying, because I had assumed the opposite.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

30 likes in reply to #31 11mo
GT
g.tanakaTL3Regular31 Aug 2025#35

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

0 likes 11mo
This topic was closed 45 days after the last reply. Closing is automatic for quiet topics so that a settled answer does not collect new questions underneath it. If you have a follow-up, open a new topic and link back to this one — that keeps both readable and gives your question its own title.

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