Cited by 60Statistical Methods and Bayesian InferenceStatistical Methods in Clinical TrialsSubstance Abuse Treatment and Outcomes

Methods to analyze treatment effects in the presence of missing data for a continuous heavy drinking outcome measure when participants drop out from treatment in alcohol clinical trials

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Witkiewitz, Katie, Falk, Daniel E., Kranzler, Henry R., Litten, Raye Z., Hallgren, Kevin A., O'Malley, Stephanie S., Anton, Raymond F., In conjunction with the Alcohol Clinical Trials Initiative (ACTIVE) Workgroup·2014·Alcoholism: Clinical and Experimental Research

Abstract

Background: Attrition is common in alcohol clinical trials and the resultant loss of data represents an important methodological problem. In the absence of a simulation study, the drinking outcomes among those who are lost to follow‐up are not known. Individuals who drop out of treatment and continue to provide drinking data, however, may be a reasonable proxy group for making inferences about the drinking outcomes of those lost to follow‐up. Methods: We used data from the COMBINE study, a multisite, randomized clinical trial, to examine drinking during the 4 months of treatment among individuals who dropped out of treatment but continued to provide drinking data (i.e., “treatment dropouts;” n = 185). First, we estimated the observed treatment effect size for naltrexone versus placebo in a sample that included both treatment completers ( n = 961) and treatment dropouts ( n = 185; total N = 1,146), as well as the observed treatment effect size among just those who dropped out of treatment ( n = 185). In both the total sample ( N = 1,146) and the dropout sample ( n = 185), we then deleted the drinking data after treatment dropout from those 185 individuals to simulate missing data. Using the deleted data sets, we then estimated the effect of naltrexone on the continuous outcome percent heavy drinking days using 6 methods to handle missing data (last observation carried forward, baseline observation carried forward, placebo mean imputation, missing = heavy drinking days, multiple imputation ( MI ), and full information maximum likelihood [ FIML ]). Results: MI and FIML produced effect size estimates that were most similar to the true effects observed in the full data set in all analyses, while missing = heavy drinking days performed the worst. Conclusions: Although missing drinking data should be avoided whenever possible, MI and FIML yield the best estimates of the treatment effect for a continuous outcome measure of heavy drinking when there is dropout in an alcohol clinical trial.

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  • FIML has been shown to produce estimates that are the best estimates of true effects under missingness, outperforming other approaches.

    “this approach has been shown to produce estimates that are the best estimates of true effects (observed in complete data sets) under conditions of missingness (e.g., Witkiewitz et al., 2014), outperforming other approaches to handling missing data.”

    From ACTing towards better living during COVID-19: The effects of Acceptance and Commitment therapy for individuals affected by COVID-19 (2022) · cites this paper as Witkiewitz et al., 2014

    The Abstract (Conclusions) says FIML and multiple imputation (MI) yielded the best estimates of treatment effects for a continuous heavy-drinking outcome when participants dropped out of an alcohol trial. The Discussion says they performed equally well, so the source does not support FIML outperforming MI or establish the claim for missing data generally. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

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Research works printed but not linked: 2

  1. FDA 2006 Medical Review of Vivitrol 21 897 US Government Rockville, Maryland
  2. National Research Council The prevention and treatment of missing data in clinical trials Washington, DC National Academies Press 2010 http://www.nap.edu/catalog.php?recordid-12955 24983040

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Authors
Witkiewitz, K., Falk, D. E., Kranzler, H. R., Litten, R. Z., Hallgren, K. A., O'Malley, S. S., Anton, R. F., & Workgroup, I. C. W. T. A. C. T. I. (.
Affiliations
  • University of New Mexico (US)
  • National Institute on Alcohol Abuse and Alcoholism (US)
  • Philadelphia VA Medical Center (US)
  • Department of Psychiatry Yale School of Medicine New Haven Connecticut
  • Medical University of South Carolina (US)
Corresponding author
Witkiewitz, Katie
Venue
Alcoholism: Clinical and Experimental Research
Publisher
Wiley
Published
2014-11
Volume
38
Issue
11
Pages
2826-2834
ISSN
  • 0145-6008 (ISSN-L)
  • 1530-0277
OpenAlex
W2096009052
Cited by
60
References
28
Citations by year
2026: 3 · 2025: 2 · 2024: 4 · 2023: 3 · 2022: 3 · 2021: 5 · 2020: 4 · 2019: 7 · 2018: 9 · 2017: 6 · 2016: 10 · 2015: 4
FWCI
7.05
Type
journal article
Language
en
Open access
Locations
  • Alcoholism Clinical and Experimental Research (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
Funders
National Institute on Alcohol Abuse and Alcoholism (1R01 AA022328-01)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods and Bayesian Inference
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
  • Health Sciences › Medicine › Epidemiology › Substance Abuse Treatment and Outcomes
Keywords
missing data, attrition, treatment discontinuation, heavy drinking, naltrexone, alcoholism treatment, multiple imputation, full information maximum likelihood, last observation carried forward, COMBINE study, treatment effect estimation
MeSH terms
Adult, Alcohol Drinking, Alcoholism, Female, Follow-Up Studies, Humans, Male, Middle Aged, Patient Dropouts, Research Design, Statistics as Topic, Treatment Outcome

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