Sex differences in pneumonia risk during COVID-19 in Mexico

This study aimed to evaluate the pneumonia risk based on the patient's sex during the COVID-19 pandemic and the early months of the endemic phase of the disease in Mexico. A retrospective cohort study was conducted using a dataset resulting from the epidemiological surveillance of COVID-19 (February 2020 to August 2023). Data from 1.6 million adults with laboratory-positive disease, were analyzed. Risk ratios (RR) and 95% confidence intervals (CI), computed through generalized linear regression models, were used. The overall risk of pneumonia was 9.3% (95% CI 9.2-9.4%), with sex-specific estimates of 7.0% (95% CI 6.9-7.1%) for women and 12.0% (95% CI 11.9-12.1%) for men. This disparity was consistently observed throughout all phases of the pandemic, including the endemic phase of the disease. After adjusting for age, predominant viral genotype at illness onset and preexisting medical conditions, men had a 3.3% higher risk of severe manifestations when compared to women (RR = 1.033, 95% CI 1.032-1.034). Our research highlights the potential role of patients' sex as a factor influencing pneumonia risk during and after the COVID-19 pandemic in Mexico. These findings may provide useful considerations for healthcare planning and policy development focused on addressing the impact of the disease on vulnerable populations.