Housing-related disparities in receipt of breast cancer screening among Medicaid beneficiaries.

76 Background: People experiencing or at risk of homelessness (PEH) are often diagnosed with advanced breast cancer, suggesting barriers to preventive care and screening. However, there is limited data that examine screening among PEH, undermining efforts to characterize and address potential disparities in screening. To address this gap, we investigated housing-related disparities in receipt of breast cancer screening in Medicaid, which disproportionately serves low-income PEH. Methods: We used a novel linkage of Pennsylvania Medicaid data with encounter-level data on housing-related services (Housing Management Information System; HMIS) from 2011 to 2017. We compared rates of biennial mammography between a cohort of Medicaid women receiving housing-related services in HMIS (i.e., a proxy for experience/risk of homelessness) and randomly sampled comparison beneficiaries without any housing services use. We estimated both unadjusted and adjusted disparities in receipt of biennial mammography (controlled for county and year fixed effects, demographic and Medicaid eligibility characteristics, and baseline healthcare utilization and comorbidities). We also examined heterogeneity in disparities by beneficiaries in the following HMIS subgroups: 1) receiving supportive housing, 2) experiencing chronic homelessness (i.e., 12+ months of homelessness), and 3) unstably housed (housed but receiving homelessness prevention services). Results: We identified 1,792 Medicaid beneficiaries with an HMIS encounter and 71,664 comparison beneficiaries. Those in the HMIS cohort were more likely to be younger, non-Hispanic Black, eligible for Medicaid due to disability, and have a higher number of inpatient visits and comorbidities. The unadjusted proportion receiving mammogram was 44.8% and 50.1% in the HMIS vs. comparison cohort, with an overall disparity of 5.3 percentage-points (pp, P <.001). This disparity estimate remained was robust to adjusting for covariates (-4.3 pp; P < .001). We found the largest adjusted disparity when comparing beneficiaries experiencing chronic homelessness (-8.5 pp; P = .038) relative to the comparison cohort. In contrast, the disparity was smaller among women receiving supportive housing (-3.7 pp; P = .098) and unstably housed women (-3.3 pp; P = .071). Conclusions: There was a significant disparity in the utilization of mammography among women PEH, especially those who experience chronic homelessness, in Pennsylvania Medicaid. Our finding illuminates the health consequences of housing insecurity and underscore a need for programs providing adequate housing, such as supportive housing, to address disparities in screening. In the meantime, greater efforts should be dedicated to improving the uptake of screening among at-risk populations at the point of contact with the healthcare system (e.g. when PEH engage with care).