Associations between social capital and screening mammography among older U.S. women

Objective: To investigate the association between county-level social capital and screening mammography rates among older women in the United States. Methods: This cross-sectional ecological study included 2765 U.S. counties, using 2018 county-level screening mammography rates among female Medicare enrollees aged 67–69 as the outcome. Social capital data were obtained from the 2018 Social Capital Project, including indices for Family Unity, Institutional Health, Collective Efficacy, and Community Health. Multivariable log-binomial regression analyses were conducted to estimate adjusted prevalence ratios (aPRs) and confidence intervals for “high” mammography rates (top 10 % nationally), controlling for county-level demographic and healthcare covariates. Stratified analyses examined associations among metropolitan and nonmetropolitan counties. Results: Mammography screening rates ranged from 17 % to 64 %, with a mean of 41 %. Strong positive associations were observed between social capital and mammography rates (Q4 vs. Q1: aPR = 2.29, 95 % CI: 1.20–4.36), particularly for the dimensions of Community Health (Q4 vs. Q1: aPR = 1.99, 95 % CI = 1.25–3.17) and Institutional Health (Q4 vs. Q1: aPR = 4.31, 95 % CI = 2.40–7.75). These associations were strongest among nonmetropolitan counties. No significant associations were found for Family Unity or Collective Efficacy. Conclusions: County-level social capital, specifically community and institutional health, is significantly associated with higher mammography screening rates, particularly in non-metropolitan areas. These findings suggest that enhancing public trust and community engagement may improve screening behaviors. Future research should explore the role of social capital at multiple levels and its influence on various cancer screening behaviors.