Can CAPTURE be used to identify undiagnosed patients with mild-to-moderate COPD likely to benefit from treatment?

ABSTRACT

Background: COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE™) uses five questions and peak expiratory flow (PEF) thresholds (males ≤350 L/min; females ≤250 L/min) to identify patients with a forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) <0.70 and FEV1 <60% predicted or exacerbation risk requiring further evaluation for COPD. This study tested CAPTURE's ability to identify symptomatic patients with mild-to-moderate COPD (FEV1 60%-80% predicted) who may also benefit from diagnosis and treatment. Methods: Data from the CAPTURE development study were used to test its sensitivity (SN) and specificity (SP) differentiating mild-to-moderate COPD (n=73) from no COPD (n=87). SN and SP for differentiating all COPD cases (mild to severe; n=259) from those without COPD (n=87) were also estimated. The modified Medical Research Council (mMRC) dyspnea scale and COPD Assessment Test (CAT™) were used to evaluate symptoms and health status. Clinical Trial Registration NCT01880177, https//ClinicalTrials.gov/ct2/show/NCT01880177?term=NCT01880177&rank=1. Results: Mean age (+SD) 61 (+10.5) years; 41% male. COPD FEV1/FVC=0.60 (+0.1), FEV1% predicted=74% (+12.4). SN and SP for differentiating mild-to-moderate and non-COPD patients (n=160) Questionnaire 83.6%, 67.8%; PEF (≤450 L/min; ≤350 L/min) 83.6%, 66.7%; CAPTURE (Questionnaire+PEF) 71.2%, 83.9%. COPD patients whose CAPTURE results suggested that diagnostic evaluation was warranted (n=52) were more likely to be symptomatic than patients whose results did not (n=21) (mMRC >2 37% vs 5%, p<0.01; CAT>10 86% vs 57%, p<0.01). CAPTURE differentiated COPD from no COPD (n=346) SN 88.0%, SP 83.9%. Conclusion: CAPTURE (450/350) may be useful for identifying symptomatic patients with mild-to-moderate airflow obstruction in need of diagnostic evaluation for COPD.