Simplified COPD screening: validation of the PiKo-6® in primary care

Aims: To determine the accuracy of the forced expiratory volume ratio at one and six seconds (FEV1/FEV6) using a hand-held, expiratory flow meter (PiKo-6®, nSpire Health, Inc.) to screen for chronic obstructive pulmonary disease (COPD) in primary care settings. Methods: Current and former smokers (> 50 years old) with no previous respiratory diagnosis (case finding [CF] = 204 subjects) or with an asthma diagnosis (differential diagnosis [DD] = 93 subjects) were evaluated using validated questionnaires, pre-bronchodilator (BD) FEV1/FEV6 and post-BD FEV1/forced vital capacity (FVC) spirometry. Results: The PiKo-6® FEV1/FEV6 showed good sensitivity and specificity (areas under the Receiver Operating Characteristic curves [95% confidence intervals]: CF = 0.85 [0.79, 0.90]; DD = 0.88 [0.80, 0.96]) and exceeded the accuracy of the questionnaires. An FEV1/FEV6 cutoff < 0.75 provided optimal sensitivity (CF = 81%; DD = 86%) and specificity (CF = 71%; DD = 67%) for COPD screening. Conclusions: The PiKo-6® allows simple and reliable screening for COPD which could optimise early referral for spirometry and early, targeted interventions for COPD.