How the 2018 Japan Floods Impacted Nursing Home Admissions for Older Persons: A Longitudinal Study Using the Long-Term Care Insurance Comprehensive Database.

OBJECTIVES:As disasters become more frequent because of global warming, countries across the world are seeking ways to protect vulnerable older populations. Although these conditions may increase nursing home admission (NHA) rates for older persons, we know of no studies that have directly tested this hypothesis. DESIGN:This was a retrospective cohort study. SETTING AND PARTICIPANTS:We analyzed data from long-term care insurance (LTCI) users in 3 Japanese prefectures that incurred heavy damage from the 2018 Japan Floods, which is the largest recorded flooding disaster in national history. Specifically, we extracted NHA data from the LTCI comprehensive database, both for disaster-affected and unaffected individuals. METHODS:We employed the Cox proportional hazards model to calculate multivariate-adjusted hazard ratios (HRs) for NHAs within a 6-month period following the 2018 Japan Floods, with adjustments for potential confounding factors. RESULTS:Of the 187,861 individuals who used LTCI services during the investigated period, we identified 2156 (1.1%) as disaster affected. The HR for NHA was significantly higher for disaster-affected (vs unaffected) individuals (adjusted HR 3.23: 95% CI 2.88‒3.64), and also higher than the HRs for older age (90-94 years vs 65-69 years: 2.29, CI 1.93‒2.70), cognitive impairment (severe impairment vs normal: 1.40, CI 1.25‒1.57), and physical function (bedridden vs independent: 2.27, CI 1.83‒2.70). According to our subgroup analyses, the adjusted HR for disaster-affected individuals unable to feed themselves was 6.00 (CI 3.68‒9.79), with a significant interaction between the 2 variables (P = .01). CONCLUSIONS AND IMPLICATIONS:Natural disasters increase the risk of NHA for older persons, especially those who are unable to feed themselves. Health care providers and policymakers should understand and prepare for this emerging risk factor.