In-hospital and long-term all-cause mortality in 75 years and older hospitalized patients with and without COVID-19

Backgrounds and purpose. In-hospital older patients have a high mortality and a higher risk of severe COVID-19 outcomes. However, it is unclear whether COVID-19 infection further increases the already-high mortality risk. This study aimed to assess whether COVID-19 could impact in-hospital and post-discharge mortality in older individuals. Methods. We compared in-hospital and up to 240 days after hospital discharge all-cause mortality in hospitalized 75 years and older patients with and without COVID-19. One-to-one propensity score allocated study participants into two balanced groups (n = 69 for both). Notably, this study was carried out in 2020, when COVID-19 vaccination was not available yet. Results. COVID-19 patients died more frequently within 30 days of hospital admission than non-COVID patients (36.2 vs 18.8%, respectively; p = 0.018). In contrast, the 240-day post-discharge mortality rate did not differ between groups (42.0 vs 47.8%, respectively; p = 0.304). After controlling for clinical covariates, we found that 30-day all cause-mortality was significantly and independently associated with COVID-19 infection (HR = 2.284, 95% CI = 1.068-4.883, p = 0.033) whereas 240-day all-cause mortality was not significantly associated with the infection (HR = 1.525, 95% CI = 0.869-2.678, p = 0.141). Conclusions. Our results confirm that COVID-19 significantly increases the mortality risk of patients aged 75 or older during hospitalization. However, we found no substantial difference in post-discharge mortality risk between COVID-19 and non-COVID-19 patients. We suggest that continued monitoring of COVID-19 patients after discharge remains crucial to understand the breadth and severity of the long-term effects of SARS-CoV-2 infection, particularly as currently the number of COVID-19 unvaccinated individuals is still high.