Women and Racial Minorities are Marginalized in Trials of Medications for Alcohol Use Disorder

Women and racial minorities are seriously underrepresented in trials of medicines for alcohol use disorder (AUD) despite evidence that these treatments affect demographic groups differently. This is according to a review in Alcoholism: Clinical & Experimental Research, which may be the first to evaluate sex and racial representation in studies relating to the three pharmacological treatments approved by the Food and Drug Administration (FDA) for AUD. Previous research indicates that sex and race/ethnicity likely influence the prevalence of AUD, its risk of health consequences, and the effectiveness of treatments.

In 1993, Congress passed the National Institutes of Health (NIH) Revitalization Act, requiring NIH-funded research to include more women and members of racial and ethnic minorities — a route to improving clinical effectiveness and reducing disparities in health outcomes. Subsequently (in 2001), the NIH mandated that study investigators conduct “subgroup” analyses comparing treatment outcomes between demographic groups.

Psychology researchers from the University of Rhode Island reviewed 102 articles published since 1994. The articles reported a trial of at least one of the three medicines approved by the FDA for treating AUD: acamprosate, naltrexone, and disulfiram. NIH funding was reported in 44 of these studies and pharmaceutical funding in 14; 32 did not report their funding source.

Only 12% of the reviewed studies fully reported the sex and race or ethnicity of trial participants; all of these related to naltrexone, none to acamprosate or disulfiram. Eleven studies were sex-specific (nine focused on men, two on women); 48 did not report the proportion of women included. Only one article included transgender participants (those assigned male at birth, identifying as women). In addition, the trials were dominated by White participants. Six articles focused on specific racial or ethnic groups. Of the remaining 96, 45 did not report including people of color, and many of those that did provided no further racial or ethnic data. Articles relating to acamprosate were the least likely to report on race or ethnicity. The review included 55 studies conducted in the US. Of these, only ten fully reported their sample’s sex and racial/ethnic breakdown; six were sex- or race-specific.

Of particular concern to the reviewers, only 6% of studies included the mandated subgroup analysis of differences in treatment outcomes by sex or race/ethnicity. Just 17% of articles acknowledged that uneven sex and race/ethnicity sampling limited the generalizability of the study findings.

Previous research has found that the representation of women and racial/ethnic minorities in pharmacological studies generally remains low. The reviewers urge considerably greater efforts to include women and people of color in trials of AUD medications, with specific recommendations for grant reviewers, researchers, and journal editors. They address the socioeconomic factors that suppress diversity in the STEM fields, which may contribute to uneven sample characteristics, and call for the exploration of factors that may dissuade members of racial/ethnic minorities from participating in clinical trials.

A Call to Action: A systematic review examining the failure to include females and members of minoritized racial/ethnic groups in clinical trials of pharmacological treatments for alcohol use disorder. M. Schick, N. Spillane, K. Hostetler (pages xxx).

ACER-20-4438.R2