Identifying modifiable risk factors to improve immigrant breast cancer screening in the United States.

1530 Background: Despite marked reductions in breast cancer mortality since 1990, recent data suggest that progress has slowed—owing in part to plateaus in breast cancer screening in underserved populations. Historically low rates of screening coupled with rising breast cancer incidence make immigrants an important population for targeted intervention. Herein, we (1) compare contemporary rates of breast cancer screening among immigrants versus US natives; and (2) identify modifiable risk factors to inform the development of interventions to improve screening among immigrants in the United States. Methods: Using data from the 2019 and 2021 National Health Interview Surveys, screening eligible female participants (ages 40-79 years old) were identified, then classified by immigrant status as defined by nativity (US native vs. foreign-born). Primary outcome was receipt of screening mammogram in the last two years. Logistic regression models examined associations between immigrant status and mammography, with and without adjustments for age, metropolitan residence, overall health status, and survey year. Sequential analysis was then used to assess the degree to which modifiable social risk factors influence the magnitude of the association between immigrant status and mammography. Results: Of 20,090 female participants included in the study, 20% were immigrants. Compared to US natives, immigrants were less likely to have received a mammogram in the last two years (67% vs. 72%, aOR [95%CI], 0.87 [0.78-0.96], p=0.006)—an effect that was most pronounced among immigrant noncitizens (57%; 0.55 [0.47-0.64], p<0.001) but reversed among immigrants with US citizenship (74%; 1.14 [1.01-1.29], p=0.03). Of the factors assessed, having a usual source of care (5.73 [4.77-6.87]) or insurance (4.60 [3.74-5.67]) was associated with the greatest odds of biennial mammography, followed by educational attainment (1.38 [1.19-1.60]) and employment (1.19 [1.09-1.30]; all p<0.001). While having a usual source of care or employment attenuated—but did not eliminate—the association between immigrant status and mammography (0.87 [0.78-0.96], p=0.01 and 0.89 [0.80-0.99], p=0.03, respectively), this finding was not observed upon inclusion of insurance status or education in sequential models (0.97 [0.87-1.09], p=0.6 and 1.09 [0.96-1.21], p=0.13, respectively). With respect to insurance type, Medicare Advantage (4.60 [3.74-5.67]) conferred the largest benefit, followed by private insurance (4.54 [4.00-5.26]), Medicaid (2.63 [2.20-3.14]), and Medicare (4.39 [3.53-5.46]; all p<0.001). Conclusions: Breast cancer screening remains low in noncitizen immigrant populations. Targeted interventions to improve access to health insurance coverage and primary care for noncitizens may be most effective for improving rates of screening mammography among immigrants and thus warrant further investigation.