“What’s sex and gender got to do with it?” A scoping review of sex and gender-based analysis in pharmacoepidemiologic studies of medication adherence

BACKGROUND: Medication taking is a complex multidimensional behaviour that may be impeded by a range of biological and psychosocial factors, including sex and gender. We aimed to synthesize how sex and gender have been reported and analyzed in pharmacoepidemiologic studies of medication. METHODS: We searched for English-language peer-reviewed articles of observational studies (e.g., cross-sectional, cohort, case-control) that examined medication adherence among adults and included sex and/or gender in their reporting. RESULTS: We included 937 studies among 530,537,287 participants published between 1979 and 2021. Most studies were cross-sectional (47%), lasted < 1 year (35%), examined self-reported adherence (53%), did not assess specific adherence problem(s) (40%), and included medications for cardiovascular conditions (24%) or systemic infections (24%). A quarter (25%) of studies used sex and gender interchangeably, over a third (36%) of studies that reported gender data likely collected data on sex, and less than 1% of studies described sex and gender as distinct variables. Studies of cisgender participants more often reported that females/women experienced greater adherence problems compared to often than males/men (31% vs 20%), particularly discontinuation and cost-related non-adherence. Only 21 studies (2%) reported on transgender individuals, and these predominantly examined antiretroviral medications for HIV. CONCLUSIONS: Our review revealed substantial conflation of sex and gender in studies of medication adherence as well as a paucity of research among transgender individuals. Moreover, our synthesis showed sex/gender disparities in medication taking with studies reporting greater medication adherence problems among cisgender women and transgender participants compared to cisgender men.

• Population(s)
  • General HIV+ population
• Prevention, Engagement and Care Cascade
  • Engagement and Care Cascade
• Engagement and Care Cascade
  • Treatment