RESUMO
INTRODUCTION: COPD is a highly prevalent but underdiagnosed disease, due to the limited availability of forced spirometry (FS) in primary care (PC). Microspirometers are inexpensive, easy-to-use devices that can measure FEV6 and FEV1/FEV6, and may help reduce underdiagnosis. The aim of this study was to validate the Piko-6 COPD screening device by demonstrating a good correlation with standard FS. METHODS: FS and Piko-6 determinations were made in 155 patients suspected of having COPD. The correlations, ROC curves, and Youden's index of both methods were compared, taking FS as the gold standard. RESULTS: FEV1, FVC and FEV6 correlation coefficients and FEV1/FVC and FEV1/FEV6 ratios were 0.87 (CI 0.836-0.909), 0.729 (CI 064-0.795) and 0.947 (95% CI 0.928-0.961), respectively. The ROC curve for FEV1 determined by Piko-6 achieved an area under the curve of 0.86 (95% CI: 0.78-0.92). Youden's index with a cut-off point of 0.70 for FEV1/FEV6 was 0.97. CONCLUSIONS: Piko-6 may be useful for COPD screening in PC. Measurements obtained with this device correlate well with those determined by FS, particularly the FEV1/FEV6 ratio. This, combined with its low cost and ease of use, may contribute to reducing COPD underdiagnosis, although its exact role in the diagnostic process remains to be determined.
