How Well Does CAPTURE Translate?: An Exploratory Analysis of a COPD Case-Finding Method for Spanish-Speaking Patients

Abstract

Background: This study tested the properties of a Spanish translation of CAPTURE (COPD Assessment in Primary Care To Identify Undiagnosed Respiratory Disease and Exacerbation Risk) with selective use of peak expiratory flow (PEF).

Methods: This study comprised analyses of data from the Spanish-speaking cohort of the cross-sectional, case-control study used to develop CAPTURE. Translation procedures included forward and backward translation, reconciliation, and cognitive interviewing to assure linguistic and cultural equivalence, yielding CAPTURE-S. Spanish-speaking participants were recruited through one center and designated as case subjects (clinically significant COPD: FEV₁ ≤ 60% predicted and/or at risk of COPD exacerbation) or control subjects (no or mild COPD). Subjects completed a questionnaire booklet that included 44 candidate items, the COPD Assessment Test (CAT), and the modified Medical Research Council (mMRC) dyspnea question. PEF and spirometry were also performed.

Results: The study included 30 participants (17 case subjects and 13 control subjects). Their mean (± SD) age was 62.6 (11.49) years, and 33% were male. CAPTURE-S scores were significantly correlated with PEF (r = -0.78), the FEV₁/FVC ratio (r = -0.74), FEV₁ (r = -0.69), FEV₁ % predicted (r = -0.69), the CAT score (r = 0.70), and the mMRC dyspnea question (r = 0.59) (P < .0001), with significantly higher scores in case subjects than in control subjects (t = 6.16; P < .0001). PEF significantly correlated with FEV₁ (r = 0.89), FEV₁ % predicted (r = 0.79), and the FEV₁/FVC ratio (r = 0.75) (P < .0001), with significantly lower PEF in case subjects than in control subjects (t = 5.08; P < .0001). CAPTURE-S score + PEF differentiated case subjects and control subjects with a sensitivity of 88.2% and a specificity of 92.3%.

Conclusions: CAPTURE-S with selective use of PEF seems to be useful for identifying Spanish-speaking patients in need of diagnostic evaluation for clinically significant COPD who may benefit from initiation of COPD treatment.

Trial registry: ClinicalTrials.gov; No.: NCT01880177; URL: www.clinicaltrials.gov.

Keywords: COPD; case-finding; diagnosis; lung function.