Comparison of FEV1/FEV6 with FEV1/FVC in the diagnosis of COPD

Background: Globally COPD occurs. But it is a health hazard among those who smoke. The life expectancy is also reduced to a large extent. Hence early diagnosis may help prevent further progression of disease and motivate people to modify their lifestyle.Methods: Patients aged 40 years and above, attending to pulmonology OPD and in-patients with symptoms suggestive of COPD were subjected to spirometric examinations following standard protocol of test performance as laid down by ATS/ERS. Spirometric examinations were analyzed statistically to know the performance of FEV1/FEV6 ratio using a cut-off value of < 0.70 (post bronchodilator) arbitrarily as against FEV1/FVC ratio of < 0.70 (post bronchodilator) in accordance with GOLD guidelines for the diagnosis of COPD.Results: Majority (83.8%) were male. Out of 229 patients 197 patients had airways obstruction as per post bronchodilator FEV1/FVC of < 0.70. Among 197 patients who were diagnosed as having COPD as per post bronchodilator FEV1/FVC ratio, 180 (91.37%) patients had an FEV1/FEV6 value < 0.70. Among 192 male patients, 170 were diagnosed as having COPD as per post bronchodilator FEV1/FVC ratio of < 0.70 as against 153 as per post bronchodilator FEV1/FEV6 ratio of < 0.70. Among 37 female patients 27 were found to have COPD based on both FEV1/FVC and FEV1/FEV6 post bronchodilator values.Conclusions: FEV1/FEV6 ratio is an acceptable alternative to FEV1/FVC ratio in the diagnosis of COPD in patients aged 40 years and above and with risk factors for COPD.