ABSTRACT
Background: While men have experienced higher risks of SARS-CoV-2 infection compared to women, an analysis of sex differences by age in severe outcomes during the acute phase of infection is lacking. Objectives: The purpose of this study was to assess heterogeneity in severe outcome risks by age and sex by conducting a retrospective cohort study of community-dwelling adults in Ontario who tested positive for SARS-CoV-2 infection during the first 3 waves. Methods: Adjusted odds ratios were estimated using multilevel multivariable logistic regression models including an interaction term for age and sex. The primary outcome was a composite of severe outcomes (hospitalization for a cardiovascular (CV) event, intensive care unit admission, mechanical ventilation, or death) within 30 days. Results: Among 30,736, 199,132, and 186,131 adults who tested positive during the first 3 waves, 1,908 (6.2%), 5,437 (2.7%), and 5,653 (3.0%) experienced a severe outcome within 30 days. For all outcomes, the sex-specific risk depended on age (all P for interaction <0.05). Men with SARS-CoV-2 infection experienced a higher risk of outcomes than infected women of the same age, except for the risk of all-cause hospitalization being higher for young women than men (ages 18-45 years) during waves 2 and 3. The sex disparity in CV hospitalization across all ages either persisted or increased with each subsequent wave. Conclusions: To mitigate risks in subsequent waves, it is helpful to further understand the factors that contribute to the generally higher risks faced by men across all ages, and the persistent or increasing sex disparity in the risk of CV hospitalization.