Purpose: Health disparities by sexual orientation fluidity are relatively unexplored in middle or late adulthood. We assessed differences in self-reported health and health behaviors according to fluidity status. Methods: We analyzed baseline (2002-2010) and follow-up (2015-2023) survey data of Research Program on Genes, Environment, and Health participants. We classified people based on responses to sexual orientation questions: consistently heterosexual, consistently sexual minority, and fluid (changed reported orientation). We then compared health behavior (smoking, binge drinking, and physical activity) and self-rated health (Patient-Reported Outcomes Measurement Information System and EuroQol EQ-5D-3L) across groups using linear or logistic regression with or without weights for attrition using complete case data and after multiple imputation. Results: Of the 32,058 adults (mean age: 56 years, male: 39.6%), 378 (1.2%) were fluid. Compared with consistently heterosexual adults, fluid individuals had significantly worse self-rated health scores after adjustment for demographics and attrition, although most differences were not clinically meaningful. No differences in health behavior were noted in adjusted analyses. Conclusion: Sexual orientation fluidity occurs in older adults, and this group may have worse health than their heterosexual counterparts.
Keywords: fluidity; health behavior; health disparities; self-rated health; sexual orientation.