Horizontal inequity in long-term care access under universal coverage in Japan (2001-2022)

Japan has achieved universal public coverage of long-term care (LTC) through a mandatory LTC insurance system established in 2000. However, evidence remains limited on whether this system ensures equal access to care based on needs, regardless of the ability to pay.

To examine income-related horizontal inequities in LTC utilisation in Japan and assess how equity patterns evolved across care types between 2001 and 2022.

We used nationally representative repeated cross-sectional data on community-dwelling individuals aged 40 and older who were certified LTC insurance beneficiaries from 2001 to 2022 (39,743 observations). Horizontal inequities in LTC utilisation were measured using corrected concentration indices, adjusted for care needs.

After adjusting for care needs, formal care in the early years of LTC insurance, particularly home-visit services, was more concentrated among lower-income individuals, while informal care, mixed care, and short-term stays were more concentrated among higher-income individuals. Over time, inequities in care arrangements and most formal services moved closer to equity and were not reversed by later copayment increases for higher-income users. Unmet care needs were low in prevalence and largely equitably distributed. Need-adjusted time spent by primary caregiver was more concentrated among lower-income individuals.

The findings suggest that Japan's means-tested copayment system, together with caps on out-of-pocket payments, has not impeded equitable access to LTC services for lower-income users. However, inequities persist for services involving additional user charges. Policymaking should also consider household composition and caregiving norms that influence care composition across socioeconomic groups and strengthen targeted caregiver support.