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Open-label extensions: what survives and what does not

Evidence › Trials discontinuation & dropout randomised trial estimand

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PSundbergTL2Member24 Feb 2026#1

Posting this under the heading it deserves: Open-label extensions: what survives and what does not Everything below is what sits behind that.

I have spent a fortnight trying to pin open-label extensions down and I want to set out where I have got to, because I suspect the honest answer is duller than the thread this will produce.

What I have: a consistent observation across a small number of cases, collected the same way each time. What I do not have: any controlled comparison, or any reason to think my cases are representative.

The specific question is whether the pattern survives once the obvious confounder is removed. I cannot remove it with what I have.

53 likes 5mo

q.zhao_qaTL3Quality assurance13 Mar 2026#2

Second this, and I would have said it less carefully.

0 likes 5mo

i.lehtinenTL225 Mar 2026#3

Building on the opening post rather than restating it.

Open-label design: unblinded trials admit expectation effects. For weight-loss trials where one arm loses substantial weight and the other does not, complete blinding is impossible anyway. The unblinded nature is a limitation worth noting.

Written from notes rather than memory, which is why the numbers are specific.

5 likes 4mo

unit_conversionTL3Regular5 Apr 2026#4

Post #3 put the caveat in the right place and I want to underline it.

An open-label trial is not worthless and its subjective endpoints deserve more scepticism than its objective ones. That is a graded judgement rather than a verdict.

14 likes 4mo

m.balogunTL215 Apr 2026#5

PSundberg, post #1: Posting this under the heading it deserves: Open-label extensions: what survives and what does not Everything below is what sits behind that. I have spent a fortnight trying to pin open-label extensions down and I want to set out where I have got to, because I suspect the honest answer is duller than the thread this will produce. What I… Go to post

Risk of bias: structured appraisal of internal validity. Key things to assess: randomisation method (was it truly random or could someone predict the next assignment), concealment (could randomisation be subverted), blinding (who was blinded and why or why not), completeness of outcome reporting.

21 likes in reply to #1 3mo

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Primary endpoint hierarchies and why order matters — one year onEvidence › Trials · 61 replies

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