The Role of FEV6 in the Diagnosis of Obstructive Airway Disease for the Old Age

ABSTRACT

BACKGROUND: The most widely used pulmonary function test is spirometry. It is a relatively simple and noninvasive test that measures the volume of air expelled from fully inflated lungs. However, spirometry is an effort-dependent test that requires careful instruction and the full cooperation of the test subject. Because the old patients have relatively longer expiration time than the young patients, it is difficult for both old age and technician to fulfill the end of test criteria for forced vital capacity (FVC) maneuver. In the present study, we aimed to investigate whether forced expiratory volume in six seconds (FEV6) could be utilized in place of FVC in the detection of airway obstruction for the old age. METHODS: Total 353 old age (> or =65years) were enrolled in this study and performed spirometry. Subjects were divided into two groups by FEV1/FVC as the gold standard for diagnosing obstructive airway disease; Group I 132 patients with FEV1/FVC> or =70% , Group II 221 patients with FEV1/FVC<70% The relationship between FVC and FEV6 values were analyzed in both groups and differences between the groups were investigated. RESULTS: The mean difference of FVC and FEV6 values (FVC-FEV6) was 138.4+/-23.0 mL (5.06+/-2.86%). This difference was found to be higher in group II (189.4+/-162.5 mL, 7.0+/-5.4%) than group I (52.9+/-47.3 mL, 1.9+/-1.5%). When FEV1/FVC is taken as the gold standard, FEV1/FEV6 had negative predictive value of 87.4% and a sensitivity of 91.4% in the detection of obstructive airway disease. Conclusion: FEV6 was a relative good candidate for parameter in the detection of airway obstruction in the old age for whom it is difficult to fulfill acceptable FVC maneuver. However, additional researches are needed to determine the usefulness of FEV6 in detecting obstructive airway disease of old age.