Accuracy of Six Chronic Obstructive Pulmonary Disease Screening Questionnaires in the Chinese Population

Chronic obstructive pulmonary disease (COPD) is under diagnosis in China. This study aimed to evaluate the accuracy of six COPD screening questionnaires for the early detection of COPD.

We recruited patients aged ≥35 years, presenting at the First Affiliated Hospital of China Medical University in 2021. All participants completed the COPD Diagnostic Questionnaire (CDQ), Revised COPD Diagnostic Questionnaire (Revised-CDQ), COPD Population Screener (COPD-PS), COPD Screening Questionnaire (COPD-SQ), COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE), and Lung Function Questionnaire (LFQ). The patients underwent spirometry testing with further bronchodilator testing for those with FEV₁/FVC values of <0.70. Receiver operating characteristic curves (ROC) were drawn for each questionnaire. The sensitivity, specificity, positive predictive (PPV), negative predictive (NPV), and area under the curve (AUC) values of the optimal cut-off and previously reported scores were estimated and compared.

Of 909 patients who completed the six screening questionnaires and spirometry testing, 330 patients were newly diagnosed with COPD. AUC values for the LFQ, Revised CDQ, COPD-PS, CDQ, COPD-SQ, and CAPTURE were 0.785 (95% confidence interval: 0.752-0.812), 0.762 (0.727-0.795), 0.745 (0.707-0.778), 0.731 (0.695-0.762), 0.703 (0.671-0.734), and 0.667 (0.635-0.702), respectively. The optimal cut-off scores for CDQ, Revised-CDQ, COPD-PS, COPD-SQ, CAPTURE, and LFQ were: 19, 19, 5, 17, 3, and 16 points, respectively. Compared with the previously recommended values, the present cut-off values for the CAPTURE and LFQ had better screening accuracy. The LFQ performed better than the CDQ, COPD-SQ, or CAPTURE. The Revised CDQ performed better than CAPTURE or COPD-SQ. The COPD-PS performed better than CAPTURE.

All six questionnaires can discriminate between subjects with or without COPD. The LFQ performed particularly well. The CAPTURE and LFQ scores of 3 and 16 have better screening accuracy than the scores previously reported.