Prospective COPD Case Finding in a Lung Cancer Screening Program: A Pilot Study

Chronic Obstructive Pulmonary Disease (COPD) remains underdiagnosed and undertreated. Because screening asymptomatic individuals for COPD is not recommended, several case-finding tools have been explored. The CAPTURE questionnaire and peak expiratory flow rate (PEFR) (CAPTURE tool) have been tested in the primary care setting, with disappointing results. We hypothesized that these tools could yield better results in a lung cancer screening (CTLS) program, where subjects have a history of cigarette smoking and higher prevalence of COPD. We recruited 67 patients referred to a CTLS program at a single institution. Participants completed the CAPTURE and COPD Assessment Test (CAT) questionnaires. Spirometric testing was completed with a portable device and low dose chest CT was performed according to a standard protocol. The group's mean age was 66 +7 years, 43% were male, with 37 pack years smoking history. Eighteen (27%) had COPD (FEV1 of 60 + 22 % predicted) and a higher CAT score [12 (IQR 6-15)] compared to the non-obstructed group [ CAT = 7 (IQR 3-10)], p<0.02. Combining CAPTURE questionnaire with PEF generated the best COPD diagnostic criteria (Sensitivity=0.82, Specificity=0.73, AUROC=0.784), followed by combining CAPTURE questionnaire and emphysema presence; sensitivity of 0.73 and specificity of 0.71 and AUROC of 0.779. The CAPTURE questionnaire alone had a sensitivity of 0.766 and specificity of 0.616 AUROC of 0.669. The CAPTURE tool is an effective method to find COPD cases in lung cancer screening. A CT diagnosis of emphysema can substitute peak flow in this population.