Despite guideline recommendations, patients suspected of having COPD often are treated empirically instead of undergoing spirometry to confirm airflow obstruction (AFO). Accurate diagnosis and treatment are essential to provide high-quality, value-oriented care. We sought to identify predictors associated with AFO among patients with and treated for COPD prior to performance of confirmatory spirometry.
We identified a cohort of veterans with spirometry performed at Pacific Northwest Department of Veterans Affairs medical centers between 2003 and 2007. We included only patients with empirically diagnosed COPD in the 2 years prior to spirometry who were also taking inhaled medication to treat COPD in the 1 year prior to spirometry. We used relative risk regression analysis to identify predictors of AFO.
Among patients empirically treated for COPD (N = 3,209), 62% had AFO. Risk factors such as older age, prior smoking status, and underweight status were associated with AFO on spirometry. In contrast, comorbidities often associated with somatic symptoms were associated with absence of AFO and included congestive heart failure, depression, diabetes, obesity, and sleep apnea.
Comorbidities associated with somatic complaints of dyspnea were associated with a lower risk of having airflow limitations, suggesting that empirical diagnosis and treatment of COPD may lead to inappropriate treatment of individuals who do not have AFO.