Prevalence, diagnosis, and treatment of chronic obstructive pulmonary disease in a hospitalized lung cancer population: a single center study

Background: Chronic obstructive pulmonary disease (COPD) often coexists with lung cancer (LC) and has a detrimental effect on the prognosis of LC patients. Presently, there is a lack of adequate assessment regarding the management of COPD in LC patients. This study assessed the screening, prevalence, diagnosis and treatment of COPD in hospitalized LC patients and compared the management practices between two departments at our hospital. Methods: We retrospectively assessed the data of 3,578 patients diagnosed with primary LC in the Department of Respiratory and Critical Care Medicine and the Department of Thoracic Surgery from January 2019 to December 2020. We also compared the rate of spirometry, COPD diagnosis and COPD inhalation treatment between the LC patients from both departments, the proportion of patients aware of their COPD diagnosis and adhered to inhaled therapy, and analyzed factors influencing COPD diagnosis and inhalation treatment. Results: A total of 2,762 (77.2%) LC patients underwent spirometry, and the observed spirometry-defined COPD prevalence was 25.0% (690/2,762). The proportion of spirometry performed in the Department of Thoracic Surgery was significantly higher than in the Department of Respiratory and Critical Care Medicine (90.5% vs. 62.9%; P<0.001). The overall COPD diagnosis rate recorded in the discharge diagnosis in the 690 spirometry-defined COPD patients was 46.5% ( 321/690), and the COPD treatment rate during hospitalization was 45.2% (312/690). In addition, physicians from the Department of Respiratory and Critical Care Medicine had a higher diagnostic rate than surgeons from the Department of Thoracic Surgery (69.1% vs. 7.5%; P<0.001), as well as a better-standardized COPD treatment rate (60.6% vs. 18.6%; P<0.001). Further, the proportion of COPD inhalation treatment was higher among LC patients with COPD recorded in discharge diagnosis (74.8% vs. 19.5%; P<0.001), and multivariate logistic regression analysis showed that COPD recorded in discharge diagnosis significantly increased the proportion of COPD awareness post-hospitalization (P<0.001). Conclusions: This study showed that COPD could be a frequently undiagnosed and undertreated condition among LC patients, especially those hospitalized in a surgical ward. Additionally, a discharge diagnosis of COPD may increase the rate of inhalation treatment and awareness of the condition in LC patients.