Assessing Sex Differential in COVID-19 Mortality Rate by Age and Polymerase Chain Reaction Test Results; An Iranian Multi-Center Study

Background: Males are more likely to die from COVID-19 than females. In addition, the mortality rate among positive and suspected COVID-19 patients were reported in many literatures. The aim of this study is to evaluate the sex differential effect in the COVID-19 mortality by different age groups and polymerase chain reaction (PCR) test results. Methods: in a multicenter cross-sectional study from 55 hospitals in Tehran, Iran, patients were categorized as the positive, negative and suspected cases. Age group, sex and hospital wards were also assessed in analysis. Results: A total of 25481 cases (14791 males) were included in the study with the mortality rate of 12.0%. The mortality rate in positive, negative and suspected cases were 20.55%, 9.97% and 7.31%, respectively. Although the mortality in negative test group was considerable, sex was not associated with the death rate in this group. Using Cox regression model, sex had a significant effect on the hazard of death due to COVID-19 in adults and senior patients having positive and suspected PCR test results. However, sex was not found as significant factor for mortality in patients with negative PCR test occurring to different age groups. Conclusion: Regardless of other risk factors, we found that sex differential effect in COVID-19 mortality varies significantly in different age groups; therefore, appropriate strategies should be designed to protect adult and senior men from this deadly infectious disease. Furthermore, owing to the considerable death rate of COVID-19 patients with negative test results, new policies should be launched increase the accuracy of diagnosis tests.