Post-discharge all-cause mortality in COVID-19 recovered patients hospitalized in 2020: the impact of chronic kidney disease

In Brazil, the COVID-19 burden was substantial, and risk factors associated with higher in-hospital mortality rates have been extensively studied. However, information on short-term all-cause mortality and the factors associated with death in patients who survived the hospitalization period of acute SARS-CoV-2 infection is limited. We analyzed the six-month post-hospitalization mortality rate and possible risk factors of COVID-19 patients in a single center in Brazil. This is a retrospective cohort study focused on a six-month follow-up. The exclusion criteria were death during hospitalization, transference to another hospital, and age under 18. We collected data from the charts of all hospitalized patients from March 2020 to December 2020 with a positive RT-PCR test for SARS-CoV-2, resulting in a sample size of 106 patients. The main outcome was death after hospitalization, whereas comorbidities and demographics were evaluated as risk factors. The crude post-hospitalization death rate was 16%. The first 30 days of follow-up had the highest mortality rate. In a Cox regression model for post-hospitalization mortality, previous chronic kidney disease (HR, 4.06, 95%CI 1.46 - 11.30) and longer hospital stay (HR 1.01, 95%CI 1.00 - 1.02) were the only factors statistically associated with death. In conclusion, a high six-month all-cause mortality was observed. Within the six-month follow-up, a higher risk of death was observed for patients who had prior CKD and longer hospital stay. These findings highlight the importance of more intensive medical surveillance during this period.