Gender Differences in Hospital Outcomes among COVID-19 Hospitalizations

Many epidemiological studies have shown that coronavirus disease 2019 (COVID-19) disproportionately affects males, compared with females, although other studies show that there were no such differences. The aim of the present study was to assess differences in the prevalence of hospitalizations and in-hospital outcomes between the sexes, using a larger administrative database.

We used the 2020 California State Inpatient Database for this retrospective analysis. International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis code U07.1 was used to identify COVID-19 hospitalizations. These hospitalizations were subsequently stratified by male and female sex. Diagnosis and procedures were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification codes. The primary outcome of the study was hospitalization rate, and secondary outcomes were in-hospital mortality, prolonged length of stay, vasopressor use, mechanical ventilation, and intensive care unit (ICU) admission.

There were 95,180 COVID-19 hospitalizations among patients 18 years and older, 52,465 (55.1%) of which were among men and 42,715 (44.9%) were among women. In-hospital mortality (12.4% vs 10.1%), prolonged length of hospital stays (30.6% vs 25.8%), vasopressor use (2.6% vs 1.6%), mechanical ventilation (11.8% vs 8.0%), and ICU admission rates (11.4% versus 7.8%) were significantly higher among male compared with female hospitalizations. Conditional logistic regression analysis showed that the odds of mortality (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.38-1.44), hospital lengths of stay (OR 1.35, 95% CI 1.31-1.39), vasopressor use (OR 1.59, 95% CI 1.51-1.66), mechanical ventilation (OR 1.62, 95% CI 1.47-1.78), and ICU admission rates (OR 1.58, 95% CI 1.51-1.66) were significantly higher among male hospitalizations.

Our findings show that male sex is an independent and strong risk factor associated with COVID-19 severity.