Association between vaccination and preventive routines on COVID-19-related mortality in nursing home facilities: a population-based systematic retrospective chart review.

Abstract

Older and frail individuals are at high risk of dying from COVID-19, and residents in nursing homes (NHs) are overrepresented in death rates. We explored four different periods during the COVID-19 pandemic to analyze the effects of improved preventive routines and vaccinations, respectively, on mortality in NHs. We undertook a population-based systematic retrospective chart review comprising 136 NH facilities in southeast Sweden. All residents, among these facilities, who died within 30 days after a laboratory-verified COVID-19 diagnosis during four separate 92-day periods representing early pandemic (second quarter 2020), middle of the pandemic (fourth quarter 2020), early post-vaccination phase (first quarter 2021), and the following post-vaccination phase (second quarter 2021). Mortality together with electronic chart data on demographic variables, comorbidity, frailty, and cause of death was collected. The number of deaths during the four periods was 104, 120, 34 and 4, respectively, with a significant reduction in the two post-vaccination periods (P < 0.001). COVID-19 was assessed as the dominant cause of death in 20 (19%), 19 (16%), 4 (12%) and 1 (3%) residents in each period (P < 0.01). The respective median age in the four studied periods varied between 87and 89 years, and three or more diagnoses besides COVID-19 were present in 70-90% of the respective periods' study population. Considerable or severe frailty was found in all residents. Vaccination against COVID-19 seems associated with a reduced number of deaths in NHs. We could not demonstrate an effect on mortality merely from the protective routines that were undertaken.