Sex disparities in COVID-19 patients presented to a Swiss emergency department

Female sex has a comparable infection rate but better outcomes in the global COVID-19 pandemic. Most studies, however, lacked adequate controls. We wanted to know if the sex disparity findings were limited to COVID-19 patients or if they also applied to patients who came to the emergency of hospitals with similar symptoms but without COVID.

We wanted to know if the sex disparity findings were limited to COVID-19 patients or if they also applied to patients who came to the emergency of hospitals with similar symptoms but without COVID. 

Patients with symptoms of COVID-19 were selected at the University Hospital Basel's emergency department from March to June 2020. Based on nasopharyngeal PCR swab tests, patients were classified as SARS-CoV-2 positive or negative. All patients had their final diagnosis determined. The main result was a 30-day intensive care admission, rehospitalization for respiratory distress, and death from any cause. To investigate the relationship between gender and outcomes, we used Kaplan-Meier curves and Cox proportional hazards models. 

SARS-CoV-2 was discovered in 191 (18%) of 1,081 successive ER patients, with even gender distribution (17.9% female vs. 17.5% male, p = 0.855). Female sex  had a lower risk of admission to hospital (51% vs. 66%, p = 0.034), a lower need for haemodynamic support (8% vs. 20%, p = 0.029), a lower rate of intubation (10% vs. 21%, p = 0.037), and a lower risk of death (18% vs. 31%, p = 0.045; age-adjusted).

Gender disparities were greatest in patients over the age of 55 (HR for composite primary outcome in women 0.415, 95 percent CI 0.201-0.855, p = 0.017). When compared to the COVID patients, there were no gender differences in results in the unselected control group (age-adjusted HR 0.844, 95 percent CI 0.560-1.273, p = 0.419) or a sub - group of controls with upper respiratory tract infections or pneumonia (age-adjusted HR 0.840, 95 percent CI 0.418-1.688, p = 0.624).

Females had a better outcome in patients going to the ER with COVID-19 in this unselected, consecutive cohort study at a tertiary hospital in Switzerland. These gender differences appear to be unique to COVID, as no comparable controls were found.