Publication:

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.