Predictors of all-cause mortality among patients hospitalized with influenza, respiratory syncytial virus, or SARS-CoV-2 (preprint)

ABSTRACT

Background: Identification of shared and divergent predictors of clinical severity across respiratory viruses may support clinical decision-making and resource planning in the context of a novel or re-emergent respiratory pathogen. Methods: We conducted a retrospective cohort study to identify predictors of 30-day all-cause mortality following hospitalization with influenza (N=45,749; 2011-09 to 2019-05), respiratory syncytial virus (RSV, N=24,345; 2011-09 to 2019-04), or SARS-CoV-2 (N=8,988; 2020-03 to 2020-12; pre-vaccine) using population-based health administrative data from Ontario, Canada. Multivariable modified Poisson regression was used to assess associations between potential predictors and mortality. We compared the direction, magnitude and confidence intervals of risk ratios to identify shared and divergent predictors of mortality. Results: 3,186 (7.0%), 697 (2.9%) and 1,880 (20.9%) patients died within 30 days of hospital admission with influenza, RSV, and SARS-CoV-2, respectively. Common predictors of increased mortality included older age, male sex, residence in a long-term care home, and chronic kidney disease. Positive associations between age and mortality were largest for patients with SARS-CoV-2. Few comorbidities were associated with mortality among patients with SARS-CoV-2 as compared to those with influenza or RSV. Conclusions: Our findings may help identify patients at highest risk of illness secondary to a respiratory virus, anticipate hospital resource needs, and prioritize local preventions and therapeutics to communities with high prevalence of risk factors.