Disparities in mammography screening adherence in a universal welfare healthcare system: A population-based cohort study of 100,000 women

Background: Screening mammography reduces breast cancer mortality, yet adherence varies across populations even in welfare-based healthcare systems. Israel provides universal coverage and organized outreach, but disparities in utilization persist. Objective: To assess adherence to national mammography screening guidelines among Israeli women and identify sociodemographic and clinical factors associated with screening behavior. Methods: We conducted a retrospective cohort study using Clalit Health Services’ central database. A random sample of 95,603 eligible women aged 45–75 years was followed from 2006 to 2020. Adherence was calculated monthly using 24-month screening intervals and categorized as poor (<0.2), low (0.2–<0.5), moderate (0.5–<0.8), or full (≥0.8). Associations with sociodemographic, clinical, and preventive health behaviors were examined. Results: Adherence was poor in 26.6%, low in 26.9%, moderate in 28.2%, and full in 18.3% of participants. Higher adherence was associated with younger entry age, central residence, and Arab versus ultra-Orthodox affiliation, whereas lower adherence correlated with peripheral residence and higher religiosity. Obesity, diabetes, hypertension, depression, and dementia were more prevalent among poorly adherent women. Engagement in other preventive services (Pap smear, influenza and pneumococcal vaccination, colorectal screening) clustered with mammography adherence. Mortality was lower in the full adherence group (3.8%) than in the poor adherence group (43.2%; p < 0.0001). Conclusions: Despite universal coverage, substantial disparities in mammography adherence persist. Screening behavior reflects sociodemographic, cultural, and clinical determinants, and clusters with other preventive health practices, highlighting opportunities for targeted interventions.