Survey and evaluation of chronic obstructive pulmonary disease screening questionnaire suitable to the Chinese BMI classification

Abstract

Objective To evaluate the validity of a questionnaire for Chinese body mass index (BMI) classification of chronic obstructive pulmonary disease (COPD) community screening. Methods A sample of 629 subjects (254 in COPD group, 375 in non-COPD group) were enrolled to undergo pulmonary function test (PFT) at our hospital. All subjects complete a postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio of <70% defined as COPD. A screening questionnaire was completed after PFT. And the data were collected and the measurement indices validated with the Chinese BMI classification. Results Area under curve-receiver operating characteristic (AUC-ROC) of original screening questionnaire was 0.901 and the best cut-off value 19.5(20) points. Modifying BMI, the measurement indices of the questionnaire were better than before. AUC-ROC of the modified questionnaire was 0.916. The cut-off value was 16.5(17) points. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, Youden's index, positive predictive value, negative predictive value were 88.2%, 77.3%, 3.89, 0.15, 0.655, 72.5% and 90.6% respectively. Conclusions The item of BMI in COPD screening questionnaire is modified according to the Chinese BMI classification standard. And a cut-off value of 17 points is recommended. And it enhances the ability of questionnaire screening. Key words: Pulmonary disease, chronic obstructive; Questionnaires; Body Mass Index