COVID-19 Pandemic
Sex differences in COVID-19 infection and mortality in Hong Kong Hoi Ting (Alexandra) Law* Hoi Ting (Alexandra) LAW LAW WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong
Background: More men are dying from COVID-19 than women in Hong Kong. We aimed to characterize the sex difference in infection and mortality patterns across different pandemic waves, and investigate the reasons behind the males’ COVID-19 disadvantages.
Methods: We estimated sex-specific case-fatality risks (CFRs), hospital-fatality risks, and the number of cases per 100,000 population, particularly among older adults, from waves 1 to 8 of the pandemic. Parametric bootstrapping was employed to account for statistical uncertainty in the risk assessments. The adjusted and unadjusted age-specific risks were estimated and compared to explore the relationships between death and health-related variables. We also estimated the cause-specific sex mortality ratio to compare that of COVID-19 and other major causes of death.
Results: Hong Kong recorded 2876110 confirmed cases and 12737 deaths from waves 1 to 8, with 1317368 cases (45.8%) and 7523 (59.1%) mortality being males. The infection rate is similar for both sexes across waves. The odds ratios for CFRs, hospital-fatality risks, and the number of cases per 100,000 population were higher in men across all waves. Males have a significantly higher mortality risk after adjusting for all factors, and the odds of death for males were the highest among 65-79 years old in wave 7 (2.44, 95% CI: 1.62, 3.69), and were at a similar level for the population aged 80 or above for all waves. The sex mortality ratio of COVID-19 from 2020 to 2023 is similar to respiratory diseases (excluding COVID-19), cardiovascular diseases, and diabetes.
Conclusions: Despite similar infection rates for males and females across 8 waves, males experienced higher mortality risks. COVID-19 shares a similar sex ratio of mortality with respiratory diseases excluding COVID-19, suggesting the causal pathway of respiratory and COVID-19 is the same. The common health statuses, for example, smoking, could explain the disparity in COVID-19 and respiratory mortality.