One-Year Mortality in Hospital-Acquired SARS-CoV2 Infections: A Retrospective Cohort Study

ABSTRACT

RATIONALE. During the first wave of the SARS-CoV2 pandemic, many have highlighted a higher risk of mortality associated with hospital-acquired (HA) infections compared to non-hospital acquired (NHA) infections. However, there is currently limited data regarding the long-term outcome of those patients. The aim of this study was to compare the one-year mortality of patients with HA and NHA SARS-CoV2 infections. METHODS . A retrospective cohort study was conducted including all SARS-CoV2 patients hospitalized at Hôpital Maisonneuve-Rosemont, a tertiary-care hospital, during the first wave of the pandemic (March 1st 2020 to June 30th 2020). Data including demographic characteristics, comorbidities and mortality were collected using electronic medical records. Patients who died during the initial hospitalisation were excluded from the study. Hospital acquired cases were defined as a positive PCR test more than 7 days after hospital admission or an identified in-hospital epidemiological link. The follow-up period was one year after hospital discharge. To evaluate the association between HA SARS-CoV-2 infection and one-year mortality, we performed a multivariable logistic regression including the following prespecified risk factors for death in patients with SARS-CoV-2 age, sex, moderate to severe chronic renal disease (creatinine >3mg/dL or dialysis), solid tumour, diabetes, chronic obstructive pulmonary disease (COPD) and history of myocardial infarction (MI). Considering the possible interaction between age and HA status on mortality, we calculated age-group-specific odds ratios. RESULTS . Among 405 patients included in the final analysis, 127 (31.4%) were HA cases. One-year mortality was more than twofold among HA cases (22.0% vs. 9.4%). In patients less than 75 years old, HA infections were associated with a higher one-year mortality compared to NHA infections (OR 3.65;95% CI 1.04 - 12.78;p=0.042). This association was not present in patients of 75 years or more. Other factors associated with a higher one-year mortality included moderate to severe kidney disease (OR 6.99;95% CI 2.34 - 20.07;p<0.001), as well as localized solid tumors (OR 2.65;95% CI 1.15 - 6.11;p=0.023) and metastatic solid tumors (OR 41.68;95% CI 8.25 - 210.53;p<0.001). Sex, diabetes, COPD and MI did not have a statistically significant effect on one-year mortality. CONCLUSION. In patients less than 75 years old, hospital-acquired SARS-CoV2 infections were associated with higher one-year mortality. This finding highlights the fragility of those patients and the need to protect hospitalized patients from acquiring SARS-CoV2.