Gender Differences in the Diagnosis of Chronic Obstructive Pulmonary Disease after Spirometry

Background: Women are more likely than men to report delays in the diagnosis of chronic obstructive pulmonary disease (COPD), though the etiology of these delays is unknown. We sought to test whether delays in COPD diagnosis persist after the performance of spirometry. Methods: We used the Optum Labs Data Warehouse to identify patients 18 years of age and older without a prior diagnosis of COPD, with a post-bronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio of less than 0.7 on spirometry. We used a Cox proportional hazards model to compare the time to diagnosis after spirometry in men and women, adjusting for age, race, ethnicity, tobacco use, and post-bronchodilator FEV1/FVC. Results: The probability of receiving a COPD diagnosis after the performance of spirometry was lower among women than men (adjusted hazard ratio [aHR] 0.66, 95% confidence interval [CI] 0.50 to 0.88) Conclusion: In this retrospective cohort study of patients with spirometric evidence of obstruction, the time to diagnosis of COPD was greater among women than men. While previous vignette-based studies have found that gender differences in the diagnosis of COPD resolve with the performance of spirometry, we found that gender differences persist after spirometry has been performed. Clinicians were less likely to diagnose COPD in women even when spirometry supported this diagnosis.