Comparing Outcomes for Community-Acquired Pneumonia Between Females and Males: Results from the University of Louisville Pneumonia Study

Introduction: Male sex is currently considered to be a risk factor for worsened community-acquired pneumonia (CAP) outcomes compared to female sex; hence, female sex equates to a lower score on the Pneumonia Severity Index. There is no recent update on sex-based outcomes of patients with CAP. The objective of this study was to compare the outcomes of CAP between females and males. Methods: This was a secondary analysis of the University of Louisville Pneumonia Study database. It was a prospective population-based cohort study of all hospitalized adults with CAP who were residents of Jefferson County in the city of Louisville, Kentucky. The study included data from June 1, 2014, to May 31, 2016, and data from October 1, 2016, to May 31, 2017. The study population was divided into two groups: females and males. Results: Female patients had a 13% lower mortality at one year compared to males (aHR 1.13 [95% CI 1.05–1.23], P=0.002). There was no significant difference in mortality between the two groups during hospitalization or at 30-day or six-month follow-up. The median time to discharge for both female and male patients hospitalized with CAP was five days (interquartile range [IQR] 3, 9 days). The median time to clinical stability for both female and male patients hospitalized with CAP was two days (IQR 1, 4 days). Conclusion: This study shows that female patients had significantly lower one-year mortality compared to males. There was no significant difference between females and males in time to clinical stability or length of stay. Further investigation is needed to examine whether risk factors associated with female and male sex predict outcomes among hospitalized patients due to CAP.