Association of migration with hospitalization and mortality among Medicare beneficiaries with end-stage renal disease in Puerto Rico after Hurricane Maria.

BACKGROUND: Hurricane Maria, which struck Puerto Rico (PR) on September 20, 2017, was one of the worst natural disasters in modern US history. Maria disproportionately impacted chronically ill patients, such as those with end-stage renal disease (ESRD), some of whom migrated to the US mainland to receive care. OBJECTIVE: We aim to examine the association of migration with hospitalization and mortality among Medicare beneficiaries with ESRD. METHODS: Using Medicare claims data, we applied a difference-in-differences (DD) approach to compare changes in hospitalization and mortality after Hurricane Maria among migrants with ESRD relative to concurrent changes among non-migrant ESRD patients in PR from 2016 through 2019. RESULTS: The study population of 10,630 Medicare beneficiaries with ESRD initially residing in Puerto Rico between 2016 to 2019 included 1,046 (9.8%) migrants to the mainland US and 9,584 (90.2%) non-migrants who stayed in PR. After adjusting for patient characteristics, prior hospitalizations, and calendar-quarter fixed effects, migration was associated with reductions in the number of hospital admissions per quarter by 0.10 (relative reduction of 19.2%) and hospital days per quarter by 0.81 (23.5% relative reduction), with no significant impact on mortality. CONCLUSIONS: Results show that migrants from PR to the US after Hurricane Maria experienced fewer hospitalizations and unchanged mortality. The findings suggest that migration from the disaster-affected area was associated with a reduction in the use of acute care among patients with ESRD.