Six-Month Follow-up of COVID-19 Patients: Mortality and Related Factors.

Background: Currently, there is lack of evidence regarding the long-term follow-up of coronavirus disease 2019 (COVID-19) patients. The aim of this study is to present a 6-month follow-up of COVID-19 patients who were discharged from hospital after their recovery.

Methods: This retrospective cohort study was performed to assess the six-month follow-up of COVID-19 patients who were discharged from the hospital between February 18 and July 20, 2020. The primary outcome was 6-month all-cause mortality.

Results: Data related to 614 patients were included to this study. Of these 614 patients, 48 patients died (7.8%). The cause of death in 26 patients (54.2%) was the relapse of COVID-19. Also, 44.2% of deaths happened in the first week after discharge and 74.4% in the first month. Risk factors of all-cause mortality included increase in age (odds ratio [OR]=1.09; <0.001), increase in neutrophil percentage (OR=1.05; =0.009) and increase in heart rate (OR=1.06; =0.002) on the first admission. However, the risk of all-cause death was lower in patients who had higher levels of hematocrit (OR=0.93; =0.021), oxygen saturation (OR=0.90; =0.001) and mean arterial pressure (OR=0.93; =0.001). In addition, increase in age (OR=1.11; <0.001) was an independent risk factor for COVID-19-related death, while higher levels of lymphocyte percentage (OR=0.96; =0.048), mean arterial pressure (OR=0.93; =0.006) and arterial oxygen saturation (OR=0.91; =0.009) were protective factors against COVID-19-related deaths during the 6-month period after discharge.

Conclusion: Death is relatively common in COVID-19 patients after their discharge from hospital. In light of our findings, we suggest that elderly patients who experience a decrease in their mean arterial pressure, oxygen saturation and lymphocyte count during their hospitalization, should be discharged cautiously. In addition, we recommend that one-month follow-up of discharged patients should be take place, and urgent return to hospital should be advised when the first signs of COVID-19 relapse are observed.