To explore the value of handheld COPD-6 spirometry for early COPD detection in high risk elderly population in community.

From January 2018 to December 2019 at Dongshan Community Health Service Center, Jiangning District, Nanjing City, a free physical examination was performed on the elder population over 60 years who had high risk factors of COPD. Handheld COPD-6 spirometry was performed pre- and post-bronchodilator, the forced expiratory volume in one second (FEV₁) , the forced expiratory volume in one second as a percentage of the predicted value (FEV₁%prep) , the forced expiratory volume in six second (FEV₆) , the percentage of forced expiratory volume in six second to the predicted value (FEV₆%prep) , and the value of FEV₁/FEV₆ were evaluated and recorded. With FEV₁/FEV₆<80% as the initial screening positive pre-bronchodilator, retests were performed both with handheld COPD-6 spirometry and confirmatory spirometry after inhaling bronchodilator. Using FEV₁/Forced vital capacity (FVC) <70% as the gold standard by confirmatory spirometry, receiver-operator characteristic (ROC) curve analysis was used to obtain the best diagnostic threshold of FEV₁/FEV₆. Sensitivity, specificity, positive predictive value, and negative predictive value were used to evaluate the diagnostic value of the handheld COPD-6 spirometer.

Out of the 382 participants, COPD was confirmed in 75 according to FEV₁/FVC<70% post-bronchodilator. There was no statistically significant difference between FEV₁%pred pre- and post-bronchodilator by handheld COPD-6 spirometry (t=-0.971, P=0.703) ; There was no statistically significant difference among FEV₁%pred in two tests (t=-2.352, -1.429; P=0.396, 0.058) . The FEV₁%pred detected by handheld COPD-6 spirometry post-bronchodilation was positively correlated with confirmatory spirometry (r=0.969, P<0.05) . Compared with FVC%pred and FEV₆%pred post-bronchodilation, the difference was statistically significant (t=-3.170, P=0.005) ; and the FEV₆%pred was positively correlated with the FVC%pred (r=0.653, P<0.05) . There was no statistically significant difference between FEV₁/FEV₆ and FEV₁/FVC post-bronchodilation (t=1.735, P=0.084) ; and there was substantial agreement between the two diagnostic (r=0.871, P<0.05) . The FEV₁/FEV₆ cut-off with the greatest sum of sensitivity and specificity was 71% pre-bronchodilator, the sensitivity, specificity, positive and negative predictive values were 80.0%, 79.2%, 90.6% and 48.5% respectively. The greatest sum of sensitivity and specificity was 75% post-bronchodilator, the sensitivity, specificity, positive and negative predictive values were 80.0%, 98.8%, 98.4% and 58.3% respectively.

It is feasible to use FEV₁/FEV₆ as an indicator to screen COPD patients in elderly high-risk populations. It is recommended to use FEV₁/FEV₆<71% before bronchodilation and FEV₁/FEV₆<75% after diastole as the screening criteria.