Decomposing income inequalities in breast and cervical cancer screening non-adherence in France: The CONSTANCES cohort survey

Abstract

Background Socioeconomic inequalities are observed in breast cancer screening (BCS) and cervical cancer screening (CCS) in France. A large range of determinants is associated with BCS and CCS. Most of these determinants are socially stratified and are likely to contribute to socioeconomic inequalities in BCS and CCS. Various factors associated with BCS and CCS non-adherence have been identified in many studies. However, limited evidence exists on their contributions to socioeconomic inequalities. This study quantified the contributions of these determinants to BCS and CCS income inequalities in France. Methods The study utilised the 2012–2014 baseline data in the CONSTANCES survey conducted in France (10,260 women for BCS and 18,761 for CCS). Screening non-adherence was defined by having last BCS for more than 2 years and last CCS for more than 3 years. The standard concentration index (Ch) was computed to measure the income inequalities in BCS and CCS non-adherence. Decomposition analyses quantified the contributions of the determinants to the income inequalities. We used the method proposed by Wagstaff. A large range of determinants were accounted for: sociodemographic (age, partner, children, migration status, area of residence), socioeconomic (education, employment status, unmet healthcare need for financial reasons), healthcare access (health insurance for low-income individuals, potential spatial accessibility to gynecologists and general practitioners), health status (measured BMI, taking anti-diabetic treatment, taking antihypertensive treatment, self-reported physical limitations, self-reported cognitive limitation, personal history of cancer, family history of cancer, perceived health status, self-reported smoking status) and healthcare use (last visit to a gynaecologist from inclusion, number of GP visits during the inclusion year; and last glucose test from inclusion). Results BCS non-adherence was concentrated towards the lower income groups [Ch = −0.0756 (95% CI: −0.1000 to −0.0512)], these inequalities were explained mainly by less frequent visit to gynaecologist (50.0%), more unmet healthcare needs (13.9%) and higher BMI status (8.4%) in lower income groups. CCS non-adherence was concentrated towards the poorer groups [Ch = −0.1264 (CI: −0.1422 to −0.1106)], these inequalities were mostly explained by less frequent visit to gynaecologist (54.6%), having a partner (8.2%), and more unmet healthcare needs (7.0%) in lower income groups. Regular visits to general practitioner contributed negatively to both inequalities in BCS and CCS non-adherence (−10.2% and −4.8%, respectively): they were associated with lower BCS and CCS non-adherence and they were more common in poorer women. Conclusion Awareness of healthcare professionals should be raised regarding different factors contributing to the socioeconomic inequalities in BCS and CCS non-adherence as they are in the front-line of giving health advice adapted to women's characteristics.