Consumption outcomes in clinical trials of alcohol use disorder treatment: Consideration of standard drink misestimation

ABSTRACT

Background. The Food and Drug Administration recently added a new clinical endpoint for evaluating the efficacy of alcohol use disorder (AUD) treatment that is more inclusive of treatment goals besides abstinence: no heavy drinking days (NHDD). However, numerous critiques have been noted for such binary models of treatment outcome. Further, there is mounting evidence that participants inaccurately estimate the quantities of alcohol they consume during drinking episodes (i.e., drink size misestimation), which may be particularly problematic when using a binary criterion (NHDD) compared to a similar, continuous alternative outcome variable: percent heavy drinking days (PHDD). Yet, the impact of drinking misestimation on binary (e.g., NHDD) versus continuous outcome variables (e.g., PHDD) has not been studied.

Objectives. Using simulation methods, the present study examined the potential impact of drink size misestimation on NHDD and PHDD.

Methods. Data simulations were based on previously published findings of the amount of error in how much alcohol is actually poured when estimating standard drinks. We started with self-reported daily drinking data from COMBINE study participants with complete data (N = 888; 68.1% male), then simulated inaccuracy in those estimations based on literature on standard drink size misestimation.

Results. Clinical trial effect sizes were consistently lower for NHDD than for PHDD. Drink size misestimation further lowered effect sizes for NHDD and PHDD.

Conclusions. Drink size misestimation may lead to inaccurate conclusions about drinking outcomes and the comparative effectiveness of AUD treatments, including inflated type-II error rates, particularly when treatment “success” is defined by binary outcomes such as NHDD.

KEYWORDS:

• Alcohol use disorder
• treatment outcomes
• drink size
• standard drink
• statistical power
• data simulation

This article refers to:

Measurement errors and misestimation: their effects on drinking outcomes

Acknowledgments

This research was supported by grants from the National Institute on Alcohol Abuse and Alcoholism (NIAAA): F31-AA024959, PI: Kirouac; K01-AA024796, PI: Hallgren; R01-AA022328 and R01-AA025539, PI: Witkiewitz; F31-AA026773, PI: Wilson). Adam D. Wilson was supported by a training grant from NIAAA (T32-AA0018108; PI: McCrady). We would also like to acknowledge Matthew R. Pearson, Adrian J. Bravo, and Mark Prince for their statistical consultation for data simulation methodology used in the present manuscript.

Disclosures

My co-authors and I do not have any conflicts of interest that could inappropriately influence, or be perceived to influence, our work.

Additional information

Funding

This research was supported by grants from the National Institute on Alcohol Abuse and Alcoholism (NIAAA): F31-AA024959, PI: Kirouac; F31-AA026773, PI: Wilson; K01-AA024796, PI: Hallgren; R01-AA022328 and R01-AA025539, PI: Witkiewitz; Adam D. Wilson was also supported by a training grant from NIAAA (T32-AA0018108; PI: McCrady).