Measurement challenges in binge drinking research: Addressing sex and gender diversity in national surveys

Background: Accurate measurement of binge drinking is essential for understanding population-level health disparities. However, national surveys commonly rely on binary sex-based thresholds, which may introduce classification challenges when applied across diverse sex and gender classifications. Methods: Data from the 2019–2023 Behavioral Risk Factor Surveillance System were used to examine binge drinking patterns among adults reporting transgender identity. Binge drinking was defined using standard sex-based thresholds (≥5 drinks for men, ≥4 drinks for women on a single occasion). Multivariable logistic regression was used to estimate associations between sex assigned at birth, gender identity, and binge drinking, adjusting for demographic characteristics and using cisgender men and women as reference groups. Results: Estimated odds of binge drinking varied by gender identity and reference group, indicating sensitivity to sex-based thresholds. Compared to cisgender women, individuals assigned female at birth who reported transgender identity had higher odds of binge drinking (e.g., transmasculine: OR = 1.55, 95% CI = 1.08–2.22), although these differences were not consistently observed when compared to cisgender men. Additionally, 26% of individuals identifying as transmasculine reported a sex assigned at birth of male, and 13% of those identifying as transfeminine reported a sex assigned at birth of female, suggesting reporting differences that may reflect variation in how survey questions are interpreted. Conclusions: Differences in how sex and gender are defined in national surveys may introduce measurement uncertainty in the application of standard sex-based binge drinking thresholds. A clearer distinction between sex assigned at birth and gender identity may improve the interpretability of surveillance estimates.