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Randomized Controlled Trial
. 2011 Feb 7:342:d40.
doi: 10.1136/bmj.d40.

Strategy for intention to treat analysis in randomised trials with missing outcome data

Ian R White  1 , Nicholas J Horton, James Carpenter, Stuart J Pocock
Affiliations
Randomized Controlled Trial

Strategy for intention to treat analysis in randomised trials with missing outcome data

Ian R White et al. BMJ. .

Abstract

Loss to follow-up is often hard to avoid in randomised trials. This article suggests a framework for intention to treat analysis that depends on making plausible assumptions about the missing data and including all participants in sensitivity analyses

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Conflict of interest statement

Competing interests All authors have completed the unified competing interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare no support from any organisation for the submitted work; JC has undertaken paid consultancy for various drug companies; and no other relationships or activities that could appear to have influenced the submitted work.

Figures

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Fig 1 Possible ways to impute outcome measures at visit 9 for a hypothetical participant in the obesity trial who drops out after visit 4: main analysis (last value brought forward) and three sensitivity analyses (1 assumes participants lost to follow-up return to baseline weight; 2 assumes 50% of weight regained, and 3 assumes intervention group regains a greater proportion of weight than controls)
See this image and copyright information in PMC

References

    1. Moher D, Hopewell S, Schulz KF, Montori V, Gotzsche PC, Devereaux PJ, et al. CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials. BMJ 2010;340:c689. - PMC - PubMed
    1. Peduzzi P, Wittes J, Detre K. Analysis as randomised and the problem of non-adherence: an example from the Veterans Affairs randomized trial of coronary artery bypass surgery. Stat Med 1993;12:1185-95. - PubMed
    1. Altman D. Missing outcomes in randomized trials: addressing the dilemma. Open Med 2009;3(2):e51. - PMC - PubMed
    1. Committee for Proprietary Medicinal Products. Points to consider on missing data. 2001. www.emea.europa.eu/pdfs/human/ewp/177699EN.pdf.
    1. Doody R, Gavrilova S, Sano M, Thomas R, Aisen P, Bachurin S, et al. Effect of dimebon on cognition, activities of daily living, behaviour, and global function in patients with mild-to-moderate Alzheimer’s disease: a randomised, double-blind, placebo-controlled study. Lancet 2008;372:207-15. - PubMed

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