Topic summary

About the Trials category

Evidence › Trials randomised trial estimand intention to treat Pinned Wiki

This is a generated summary. It shows the 5 most-liked posts from a topic of 11, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

j.mwangiTL4 Moderator11 Jul 2025#1

Community wiki post. Any member at trust level 3 or above can edit this post; every edit is recorded. Last edited by hana.sato on 22 Jan 2026.

28 Jul 2025 — j.mwangi: Plain-language pass on the opening paragraph.
26 Dec 2025 — mira.patel: Corrected an arithmetic slip in the second example.
22 Jan 2026 — hana.sato: Added the limitations paragraph that review asked for.

Editors: j.mwangi, mira.patel, hana.sato

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Individual randomised trials: design, population, endpoints, results, and limitations.

This post is a community wiki: any member at trust level 3 or above can edit it, and every edit is recorded with its author and a note. If the scope described here has drifted from what actually gets posted, edit it rather than starting a topic about it.

What belongs here

Questions specific to trials, with the units and the context stated.
Reports and datasets, with the collection method stated.
Disagreement about the substance, conducted in public.

What belongs elsewhere

Anything urgent belongs in Safety, immediately, and not here.
Anything about how this site works belongs in Meta.
Requests for a maintained page belong in Wiki requests.

Before posting, it is worth checking the documentation commons and this category's tag pages. A great deal of what gets asked here has a maintained answer with a review date on it, which is more reliable than a two-year-old reply.

53 likes 13mo

bench_notesTL4 Moderator12 Jul 2025#2

Staff post. Actions described here are recorded in the public moderation log and may be challenged in Meta.

Moderation notes for this category, so that nothing about how it is run is a surprise.

Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the public log with the guideline cited.

The two guidelines that come up most often in this category are R2, on supplying a source when asked, and R7, on category placement. Neither is used punitively.

14 likes 13mo

trough_indexTL3Regular16 Jul 2025#6

bench_notes, post #2: Moderation notes for this category, so that nothing about how it is run is a surprise. Topics get moved into and out of here regularly. A move is not a judgement — the category tree is not obvious from outside and putting a question in the wrong place is expected. When I move something I say so in the topic and the action appears in the… Go to post

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.

9 likes in reply to #2 12mo

BDraganovTL2Member20 Jul 2025#10

This follows post #7 rather than contradicting it.

Intent-to-treat versus per-protocol: ITT includes everyone assigned regardless of whether they took the drug. Per-protocol includes only those who completed it as intended. The two can give substantially different results.

28 likes 12mo

sa.okonkwoTL2 Moderator21 Jul 2025#11

Multiplicity and multiple comparisons: if a trial tests many hypotheses, the chance of a false positive on at least one by random chance increases. This is why pre-specification of the primary endpoint matters and why secondary endpoints are weaker evidence.

12 likes 12mo

Read the full topic (11 posts)

Suggested topics

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