Cited by 398Statistical Methods and Bayesian InferenceAdvanced Causal Inference TechniquesStatistical Methods in Clinical Trials

Dealing With Missing Outcome Data in Randomized Trials and Observational Studies

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Groenwold, Rolf H. H., Donders, A. Rogier T., Roes, Kit C. B., Harrell, Frank E., Moons, Karel G. M.·2012·American Journal of Epidemiology

Abstract

Although missing outcome data are an important problem in randomized trials and observational studies, methods to address this issue can be difficult to apply. Using simulated data, the authors compared 3 methods to handle missing outcome data: 1) complete case analysis; 2) single imputation; and 3) multiple imputation (all 3 with and without covariate adjustment). Simulated scenarios focused on continuous or dichotomous missing outcome data from randomized trials or observational studies. When outcomes were missing at random, single and multiple imputations yielded unbiased estimates after covariate adjustment. Estimates obtained by complete case analysis with covariate adjustment were unbiased as well, with coverage close to 95%. When outcome data were missing not at random, all methods gave biased estimates, but handling missing outcome data by means of 1 of the 3 methods reduced bias compared with a complete case analysis without covariate adjustment. Complete case analysis with covariate adjustment and multiple imputation yield similar estimates in the event of missing outcome data, as long as the same predictors of missingness are included. Hence, complete case analysis with covariate adjustment can and should be used as the analysis of choice more often. Multiple imputation, in addition, can accommodate the missing-not-at-random scenario more flexibly, making it especially suited for sensitivity analyses.

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  1. Lewis JA. Statistical principles for clinical trials (ICH E9): an introductory note on an international guideline. Stat Med. 1999; 18(15):1903-1942.

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Authors
Groenwold, R. H. H., Donders, A. R. T., Roes, K. C. B., Harrell, F. E., & Moons, K. G. M.
Affiliations
University Medical Center Utrecht (NL)
Corresponding author
Groenwold, Rolf H. H.
Venue
American Journal of Epidemiology
Published
2011-12-23
Volume
175
Issue
3
Pages
210-217
ISSN
  • 0002-9262 (ISSN-L)
  • 1476-6256
OpenAlex
W2097395684
Cited by
398
References
37
Citations by year
2026: 16 · 2025: 26 · 2024: 30 · 2023: 22 · 2022: 37 · 2021: 36 · 2020: 38 · 2019: 25 · 2018: 27 · 2017: 28 · 2016: 35 · 2015: 15 · 2014: 27 · 2013: 23 · 2012: 13
FWCI
17.61
Type
journal article
Language
en
Open access
Locations
  • American Journal of Epidemiology (publishedVersion)
  • PubMed (publishedVersion)
  • Radboud Repository (Radboud University) (submittedVersion)
Funders
  • Vanderbilt University
  • Radboud Universiteit
  • School of Medicine, Vanderbilt University
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods and Bayesian Inference
  • Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
Keywords
missing outcome data, multiple imputation, single imputation, complete case analysis, missing at random, missing not at random, covariate adjustment, sensitivity analysis, observational studies, estimation bias
MeSH terms
Computer Simulation, Data Interpretation, Statistical, Humans, Models, Statistical, Randomized Controlled Trials as Topic, Outcome Assessment, Health Care

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