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Review
. 2013 Sep;28(5):506-15.
doi: 10.1002/hup.2339.

Longitudinal missing data strategies for substance use clinical trials using generalized estimating equations: an example with a buprenorphine trial

Sterling McPherson  1 , Celestina Barbosa-Leiker, Michael McDonell, Donelle Howell, John Roll
Affiliations
Review

Longitudinal missing data strategies for substance use clinical trials using generalized estimating equations: an example with a buprenorphine trial

Sterling McPherson et al. Hum Psychopharmacol. 2013 Sep.

Abstract

Objective: A review of substance use clinical trials indicates that sub-optimal methods are the most commonly used procedures to deal with longitudinal missing information.

Methods: Listwise deletion (i.e., using complete cases only), positive urine analysis (UA) imputation, and multiple imputation (MI) were used to evaluate the effect of baseline substance use and buprenorphine/naloxone tapering schedule (7 or 28 days) on the probability of a positive UA (UA+) across the 4-week treatment period.

Results: The listwise deletion generalized estimating equations (GEE) model demonstrated that those in the 28-day taper group were less likely to submit a UA+ for opioids during the treatment period (odds ratios (OR) = 0.57, 95% confidence interval (CI): 0.39-0.83), as did the positive UA imputation model (OR = 0.43, CI: 0.34-0.55). The MI model also demonstrated a similar effect of taper group (OR = 0.57, CI: 0.42-0.77), but the effect size was more similar to that of the listwise deletion model.

Conclusions: Future researchers may find utilization of the MI procedure in conjunction with the common method of GEE analysis as a helpful analytic approach when the missing at random assumption is justifiable.

Keywords: generalized estimating equations; longitudinal missing data; multiple imputation; positive urine analysis imputation; psychopharmacology clinical trials; substance use disorder treatment.

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Figures

Figure 1
Figure 1
Percent of participants with a positive opioid UA using all available data across the 4-week trajectory while receiving one of two tapering schedules
Figure 2
Figure 2
Percent of participants with a positive opioid UA assuming all missing UAs were positive across the 4-week trajectory while receiving one of two tapering schedules
See this image and copyright information in PMC

References

    1. Acock A. What to do about missing values. In: Cooper H, editor. APA Handbook of Research Methods in Psychology. American Psychological Association; Washington, DC: 2012.
    1. Allison PD. Missing Data. Sage; Newbury Park, CA: 2001.
    1. Arndt S. Stereotyping and the treatment of missing data for drug and alcohol clinical trials. Subst Abuse Treat Prev Policy. 2009;4:2–3. - PMC - PubMed
    1. van Buuren S. Flexible Imputation of Missing Values. CRC Press; Boca Raton, FL: 2012.
    1. Collins LM, Schafer JL, Kam C- M. A comparison of inclusive and restrictive strategies in modern missing data procedures. Psychol Methods. 2001;6:330–351. - PubMed

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