Long-Term Morbidity and Mortality of Coronavirus Disease 2019 in Patients Receiving Maintenance Dialysis: A Multicenter Population-Based Cohort Study

Background Many questions remain about the population receiving maintenance dialysis who survived coronavirus disease 2019 (COVID-19). Previous literature has focused on outcomes associated with the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it may underestimate the effect of disease. This study describes the long-term morbidity and mortality among patients receiving maintenance dialysis in Ontario, Canada, who survived SARS-CoV-2 infection and the risk factors associated with long-term mortality. Methods We conducted a population-based cohort study of patients receiving maintenance dialysis in Ontario, Canada, who tested positive for SARS-CoV-2 and survived 30 days between March 14, 2020, and December 1, 2021 (pre-Omicron), with follow-up until September 30, 2022. Our primary outcome was all-cause mortality while our secondary outcomes included reinfection, composite of cardiovascular (CV)-related death or hospitalization, all-cause hospitalization, and admission to long-term care or complex continuing care. We also examined risk factors associated with long-term mortality using multivariable Cox proportional hazards regression. Results We included 798 COVID-19 survivors receiving maintenance dialysis. After the first 30 days of infection, death occurred at a rate of 15.0 per 100 person-years (95% confidence interval [CI], 12.9 to 17.5) over a median follow-up of 1.4 years (interquartile range, 1.1-1.7) with a nadir of death at approximately 0.5 years. Reinfection, composite CV death or hospitalization, and all-cause hospitalization occurred at a rate (95% CI) of 15.9 (13.6 to 18.5), 17.4 (14.9 to 20.4), and 73.1 (66.6 to 80.2) per 100 person-years, respectively. In addition to traditional predictors of mortality, intensive care unit admission for COVID-19 had a prolonged effect on survival (adjusted hazard ratio, 2.6; 95% CI, 1.6 to 4.3). Reinfection with SARS-CoV-2 among 30-day survivors increased all-cause mortality (adjusted hazard ratio, 2.2; 95% CI, 1.4 to 3.3). Conclusions The burden of COVID-19 persists beyond the period of acute infection in the population receiving maintenance dialysis in Ontario with high rates of death, reinfection, all-cause hospitalization, and CV disease among COVID-19 survivors.