Sex Differences in Veterans Admitted to the Hospital for Chronic Obstructive Pulmonary Disease Exacerbation

Abstract

Rationale: As chronic obstructive pulmonary disease (COPD) prevalence in women has outpaced that in men, COPD-related hospitalization and mortality are now higher in women. Presentation, evaluation, and treatment of COPD differ between women and men. Despite higher smoking rates in Veterans, little work has characterized differences in Veterans with COPD by sex. Objectives: To determine risk factors for 30-day readmission among Veterans hospitalized for COPD exacerbations and how they differed by sex. Methods: We performed a retrospective observational analysis of Veterans receiving primary care in Veterans Health Affairs facilities. We included Veterans Administration-based hospitalizations for Veterans with a COPD exacerbation (identified by International Classification of Disease, Ninth Revision codes) who survived to discharge between fiscal years 2012 and 2015. Primary outcome was 30-day readmission. Predictors ascertained before hospitalization included smoking status (current, former, never), pulmonary function testing, pulmonary medication prescriptions, and medical and psychiatric comorbidities (identified by International Classification of Disease, ninth revision codes). We created combined and sex-stratified multivariate logistic regression models to identify associations with 30-day readmission. Results: Our sample included 48,888 Veterans (4% women). Compared with men, women Veterans were younger, more likely to be nonwhite, and differed in smoking status. Women were more likely to have asthma, drug use, and several psychiatric comorbidities. Before hospitalization, women were less likely to have pulmonary function testing (76% vs. 78%; P = 0.01) or be treated with antimuscarinic (43% vs. 48%) or combined long-acting bronchodilator/inhaled corticosteroid (61% vs. 64%) inhalers. Women were more likely to receive nicotine-replacement therapy (all P < 0.01). Women had shorter length of stay (median days, 2 vs. 3; P = 0.04) and lower 30-day readmission rate (20% vs. 22%; P = 0.01). In adjusted models including both sexes, age, antimuscarinic use, comorbidities, and diagnosis of drug or alcohol use were associated with readmission; there was no association with sex and readmission risk. In models stratified by sex, associations were similar between women and men. Conclusions: This study suggests differences between women and men hospitalized for COPD regarding presentation, evaluation, and management. Readmission is strongly influenced by comorbidities, suggesting individualized and comprehensive case management may reduce readmission risk for women and men with COPD.

Keywords: chronic obstructive pulmonary disease; exacerbation; gender; readmission; sex.

Figure 1.

Forest plot of multivariable models for 30-day readmission for Veterans admitted for chronic obstructive pulmonary disease (overall and sex-stratified). Overall model reports readmission risk with sex as the predictor of interest; separate models stratified by sex were run to compare how factors associated with readmission varied by sex. Models also adjusted for sex (overall model only), age, race, and asthma. CI = confidence interval; NRT = nicotine-replacement therapy; PFT = pulmonary function test; PTSD = post-traumatic stress disorder.