Death risk in nursing homes between the prepandemic period and the COVID-19 era: a retrospective cohort study in Murcia Region, Spain

Abstract

BACKGROUND: With the end of COVID-19 status as a public health emergency of international concern, evaluating its effects on vulnerable groups like nursing home residents is crucial. We aimed to examine the mortality risk for individuals residing in nursing homes within the Murcia Region (southeast Spain) from 3 years before the pandemic to the Omicron stage. METHODS: We conducted a population-based retrospective study in 5062 nursing home residents with publicly funded beds from 1 January 2017 to 31 October 2022. This time frame was segmented into prepandemic, prevaccination, early postvaccine and Omicron stages. Mortality risk was assessed for all causes and for non-COVID-19 deaths. A novel approach using a frailty Cox-regression was implemented, treating the period as a time-dependent covariate across these time frames and accounting for age, sex, comorbidity, level of dependence, number of hospital admissions, transitioning into a nursing home after a hospital discharge and the size of the facility. RESULTS: The HR for all-cause mortality was 1.36 (95% CI 1.21 to 1.52) during the prevaccine period compared with the prepandemic one, returning to prepandemic levels in the early postvaccine stage (HR 0.99; 95% CI 0.88 to 1.13). For the Omicron period, the HR was 1.17 (95% CI 1.03 to 1.32). Excluding COVID-19 as a cause of death, the pandemic excess mortality risk faded away. CONCLUSIONS: COVID-19 significantly increased mortality risk in nursing homes, compounding the pre-existing vulnerabilities of this high-risk population. The innovative HR study approach enabled a comparative assessment of the pandemic's impact against the prepandemic baseline.