Population-level indicators associated with hormonal contraception use: a register-based matched case-control study.

BACKGROUND Monitoring factors related to hormonal contraception (HC) use is essential to evaluating public health strategies and promoting access to contraception. We aimed to examine municipal social and health indicators of HC use at the population level, and to identify patterns of inequality across Finnish municipalities. METHODS We identified all women (15-49 years) with a redeemed HC prescription in Finland in 2017 (n = 294,445), and a control group of non-users. Municipal social and health indicators at the population level were retrieved from the nationwide Statistics and Indicator Bank. Differences between the groups across 309 municipalities were calculated, and associations of municipal-specific proportions of HC users with municipal-specific indicators were studied using LASSO (Least Absolute Shrinkage and Selection Operator) models. RESULTS Sociodemographic differences between HC users and non-users were non-homogenous across municipalities. Indicators positively associated with HC use included: larger population and higher proportions of population aged 16-24 years, of household-dwelling units with one person, of persons with higher education, and of divorces among those aged 25-64. Lower HC use was associated with higher proportions of Swedish-speaking population, of those aged 7-15 years, of young people not in education/training, and of household-dwelling units in overcrowded conditions. Lower HC use was also associated with indicators of outpatient and inpatient healthcare, and of municipal finances in welfare and healthcare. CONCLUSIONS Sociodemographic differences in relation to HC use exist across Finnish municipalities. Municipal indicators of social structure, health and welfare, and investment in and use of healthcare services are related to HC use.