Intention-to-treat analysis: difference between revisions
Diff·revision 3 → 4·16:49, 21 Sep 2024
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| Revision 3 — 05:54, 5 Sep 2024 OpenLabelOtto (talk) state that the trial has reported but is not yet peer-reviewed 2,167 bytes +200 | Revision 4 — 16:49, 21 Sep 2024 AppendixAlva (talk) label the extension study as an extension study in the table 2,660 bytes +493 | ||
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| 11 | The alternative — analysing only those who completed as assigned — breaks that comparability, because completion is not random. Participants who stop because a treatment is not working, or because it is poorly tolerated, differ systematically from those who continue.{{r|hollis1999}} | 11 | The alternative — analysing only those who completed as assigned — breaks that comparability, because completion is not random. Participants who stop because a treatment is not working, or because it is poorly tolerated, differ systematically from those who continue.{{r|hollis1999}} |
| 12 | 12 | ||
| + | 13 | Intention-to-treat generally produces a more conservative estimate than a per-protocol analysis, and it answers a different question: what happens when treatment is offered, rather than what happens when it is taken as directed.{{r|hollis1999}} Which question a trial should answer depends on the comparison it was designed to make.{{r|ich_e10}} | |
| + | 14 | ||
| 13 | == Why analysing as treated fails == | 15 | == Why analysing as treated fails == |
| 14 | Randomisation makes the groups comparable on everything, measured and unmeasured. Any post-randomisation selection — dropping non-completers, excluding non-adherers, analysing by treatment actually received — reintroduces confounding by the very factors that led to the selection.{{r|hollis1999}} | 16 | Randomisation makes the groups comparable on everything, measured and unmeasured. Any post-randomisation selection — dropping non-completers, excluding non-adherers, analysing by treatment actually received — reintroduces confounding by the very factors that led to the selection.{{r|hollis1999}} |
| ⋮ | ⋮ | ||
| 22 | <ref name="ich_e9">International Council for Harmonisation, ''E9(R1): Estimands and Sensitivity Analysis in Clinical Trials'' (2019).</ref> | 24 | <ref name="ich_e9">International Council for Harmonisation, ''E9(R1): Estimands and Sensitivity Analysis in Clinical Trials'' (2019).</ref> |
| 23 | <ref name="hollis1999">Hollis S, Campbell F. "What is meant by intention to treat analysis? Survey of published randomised controlled trials." ''BMJ'' 319(7211):670–674 (1999). PMID 10480822.</ref> | 25 | <ref name="hollis1999">Hollis S, Campbell F. "What is meant by intention to treat analysis? Survey of published randomised controlled trials." ''BMJ'' 319(7211):670–674 (1999). PMID 10480822.</ref> |
| + | 26 | <ref name="ich_e10">International Council for Harmonisation, ''E10: Choice of Control Group and Related Issues in Clinical Trials'' (2000).</ref> | |
| 24 | 27 | ||
| 25 | {{DEFAULTSORT:Intention-to-treat analysis}} | 28 | {{DEFAULTSORT:Intention-to-treat analysis}} |