Factors Associated With Utilization of a Hospital-Based Self-Pay Preventive Foot-Care Clinic in Japan: A Retrospective Observational Study.

Japan is a super-aging society with universal health insurance, but routine preventive foot and nail care is reimbursed only for limited high-risk conditions. To compare patients using an insurance-funded foot-care service with those using a subsequently introduced hospital-based self-pay preventive foot-care clinic and to identify factors associated with self-pay clinic use. We retrospectively analyzed de-identified records from an insurance-funded program (April 2019-March 2023) and a self-pay preventive clinic (April 2023-March 2025). Group differences were assessed using Welch's t-test and chi-square tests. Independent predictors were estimated by multivariable logistic regression. The analysis included 1741 patients (1157 insurance-funded and 584 self-pay). Self-pay clinic users were older than insurance-funded service users (mean 76.1 versus 72.8 years) and were more likely to live alone (50.9% versus 27.0%). Older age, living alone, and higher copayment tiers were independently associated with self-pay clinic use, whereas sex and public assistance status were not. Self-pay preventive foot-care clinic use was concentrated among older patients, particularly those living alone. These findings suggest unmet demand for preventive foot and nail care, but do not establish comparative clinical effectiveness or cost-effectiveness.