Institutional social isolation and preventive health check-up attendance among public assistance recipients in Japan:...

Social isolation is a major social determinant of health, yet little is known about how institutionally shaped isolation influences preventive healthcare engagement among public assistance recipients. This study examined how social isolation affects preventive health check-up attendance among public assistance recipients in Japan. We employed a qualitative-dominant convergent mixed-methods design in an urban municipality in Japan. Quantitative survey data were collected from 444 recipients, including indicators of social contact and support. Preventive health check-up attendance during the current fiscal year was verified through claims-based medical assistance records. In-depth semi-structured interviews were conducted with 25 recipients and analyzed thematically using Braun and Clarke's approach. Quantitative and qualitative findings were integrated side-by-side. Absence of weekly face-to-face contact was highly prevalent (79.7%). In adjusted logistic regression models controlling for sex, age, household size, and employment status, participants with weekly face-to-face contact had significantly higher odds of attending preventive health check-ups (aOR = 3.59, 95% CI: 1.85-6.94). Qualitative analysis identified four interrelated themes: (1) institutional and economic constraints producing isolation, (2) stigma-driven avoidance of healthcare, (3) small ties within shared welfare spaces enabling engagement, and (4) the limits of individualized prevention and the need for structurally supported pathways, including social prescribing. Preventive health check-up attendance among public assistance recipients is not solely an individual behavioral responsibility but is socially and institutionally mediated through welfare-related displacement, stigma, and everyday interpersonal ties. Policies should incorporate socially supported preventive pathways to reduce isolation and promote health equity among marginalized welfare populations.