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

Background: 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 COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE) questionnaire and peak expiratory flow (PEF) rate (CAPTURE tool) have been tested in the primary care setting, with disappointing results. We hypothesized that these tools could yield better results in a computed tomography lung screening (CTLS) program, where individuals have a history of cigarette smoking and higher prevalence of COPD.

Methods: 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 computed tomography (CT) was performed according to a standard protocol.

Results: The group's mean age was 66 ±7 years, 43% were male, with a 37 pack-year smoking history. Eighteen (27%) had COPD (forced expiratory volume in 1 second of 60 ±22% predicted) and a higher CAT score (12 [interquartile range (IQR) 6-15]) compared to the nonobstructed group (CAT=7 [IQR 3-10]), p<0.02. Combining the CAPTURE questionnaire with PEF generated the best COPD diagnostic criteria (sensitivity=0.82, specificity=0.73, area under the receiver operating curve [AUROC]=0.784), followed by combining the CAPTURE questionnaire and emphysema presence (sensitivity=0.73, specificity=0.71, AUROC=0.779). The CAPTURE questionnaire alone had a sensitivity=0.766, specificity=0.616, and AUROC=0.669.

Conclusions: The CAPTURE tool is an effective method to find COPD cases in lung cancer screenings. A CT diagnosis of emphysema can substitute peak flow in this population.