Comparing the Performance of Two Screening Questionnaires for Chronic Obstructive Pulmonary Disease in the Chinese General Population

Impulse oscillometry-derived equation for prediction of abnormal FEV1/FVC ratio for COPD screening in Chinese population: a multicenter cross-sectional study

Background

The diagnosis of chronic obstructive pulmonary disease (COPD) is based on spirometry that requires a forced expiratory manoeuvre, which is laborious and difficult for mass screening. Impulse oscillometry (IOS) is easier than spirometry and performed with tidal breathing. We sought to develop an equation for predicting forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and screening COPD using IOS parameters.

Methods

Data from patients who simultaneously underwent spirometry and IOS were obtained from databases at five tertiary hospitals in China. Multivariable linear regression analysis was used to develop a predictive model for pre-bronchodilator (BD) FEV1/FVC. Model performance was analyzed against spirometric criteria of airflow obstruction (AO, defined as pre-BD FEV1/FVC < 0.7) and COPD (post-BD FEV1/FVC < 0.7).

Findings

Using 15,113 patients and externally validated with 9586 patients, the model estimated FEV1/FVC ratio could identified AO and spirometry-defined COPD in internal (AUC = 0.822 and 0.849, respectively) and external (AUC = 0.790 and 0.828, respectively) validation. A clinical algorithm was constructed to classify patients into three different groups: estimated FEV1/FVC < 0.7: likely COPD; estimated FEV1/FVC ≥ 0.7 and ≤0.73: suspicious for COPD; estimated FEV1/FVC > 0.73: unlikely COPD. The sensitivity and specificity for detecting spirometry-defined COPD were 88.0% and 77.0%, respectively, while the negative predictive value ranged from 93.7% to 98.6% and positive predictive value ranged from 26.5% to 62.1% across different COPD prevalence groups in the Chinese population.

Interpretation

This equation could be useful to screen for COPD particularly in community and primary care settings.

Funding

The Financial Budgeting Project of Beijing Institute of Respiratory Medicine.

Cost-effectiveness of population-based screening for chronic obstructive pulmonary disease in China: a simulation modeling study

Background

China has the highest disease burden of chronic obstructive pulmonary disease (COPD) in the world; however, the diagnosis rate remains low. Screening for COPD in the population may improve early diagnosis and long-term health outcomes for patients with COPD. In this study, we aimed to evaluate the cost-effectiveness of population-based COPD screening policies in China.

Methods

We developed a microsimulation model that simulated incidence, natural history, and clinical management of COPD over a lifetime horizon among the general population aged 35-80 years in China. We evaluated population-based screening policies with different screening methods (one-step with COPD Screening Questionnaire or two-step with additional portable spirometer test) and frequencies (one-time or every 1-10 years). We calculated the incremental cost-effectiveness ratio (ICER) of the screening policies compared with the status quo (without screening) and identified the most cost-effective screening policy. Scenario and sensitivity analyses were performed to assess the impact of key parameters and the robustness of model results.

Findings

Compared with the status quo, all population-based COPD screening policies were cost-effective with estimated ICERs ranging between $8034 and $13,209 per quality-adjusted-life-year (QALY), all under the willingness-to-pay value of $38,441/QALY (three times China's gross domestic product per capita). A total of 0.39%-8.10% of COPD-related deaths and 0.58%-2.70% of COPD exacerbations were projected to be averted by COPD screening. Among all screening policies, annual two-step screening was the most cost-effective. Improving the linkage from screening to diagnosis and treatment could further increase population health benefits and the cost-effectiveness of COPD screening.

Interpretation

Population-based screening for COPD could be cost-effective in China. Offering public programs for COPD screening similar to existing preventive health services for other chronic diseases could be a promising strategy to improve population health outcomes and mitigate the disease burden of COPD in China.

Funding

Alexander von Humboldt Foundation, National Natural Science Foundation of China, CAMS Innovation Fund for Medical Science, Chinese Academy of Engineering project, and Horizon Europe.

Screening performance of COPD-PS scale, COPD-SQ scale, peak expiratory flow, and their combinations for chronic obstructive pulmonary disease in the primary healthcare in Haicang District, Xiamen City

Objectives

This study aimed to evaluate the screening performance of COPD-PS questionnaire, COPD-SQ questionnaire, peak expiratory flow (PEF), COPD-PS questionnaire combined with PEF, and COPD-SQ questionnaire combined with PEF for chronic obstructive pulmonary disease (COPD).

Methods

This was a cross-sectional study. We distributed self-designed surveys and COPD screening scales (COPD-PS questionnaire and COPD-SQ questionnaire) to residents who underwent physical examination in five community health centers in Haicang District, Xiamen City, from February 2023 to May 2023, and measured their lung function and PEF with a portable device. We used logistic regression to obtain the coefficients of COPD-PS questionnaire, COPD-SQ questionnaire, and PEF, and plotted the receiver operating characteristic curves of each tool for diagnosing COPD and moderate-to-severe COPD. We evaluated and compared the optimal cut-off points and scores of sensitivity, specificity, Youden index, and area under the curve (AUC) values, and assessed the screening efficiency of different methods.

Results

Of the 3,537 residents who completed the COPD-SQ questionnaire, COPD-PS questionnaire, and spirometry, 840 were diagnosed with COPD. We obtained the coefficients of COPD-PS questionnaire combined with peak expiratory flow (PEF), and COPD-SQ questionnaire combined with PEF, by logistic regression as -0.479-0.358 × PEF +0.321 × COPD-PS score and - 1.286-0.315 × PEF +0.125 × COPD-SQ score, respectively. The sensitivity of diagnosing COPD by COPD-SQ questionnaire, COPD-PS questionnaire, PEF, COPD-PS questionnaire combined with PEF, and COPD-SQ questionnaire combined with PEF were 0.439, 0.586, 0.519, 0.586, 0.612 respectively, and the specificity were 0.725, 0.621, 0.688, 0.689, 0.663 respectively, with ROC values of 0.606 (95%CI: 0.586-0.626), 0.640 (0.619-0.661), 0.641 (0.619-0.663), 0.678 (0.657-0.699), 0.685 (0.664-0.706) respectively. The sensitivity of diagnosing GOLD II and above by COPD-SQ questionnaire, COPD-PS questionnaire, PEF, COPD-PS questionnaire combined with PEF, and COPD-SQ questionnaire combined with PEF were 0.489, 0.620, 0.665, 0.630, 0.781 respectively, and the specificity were 0.714, 0.603, 0.700, 0.811, 0.629 respectively, with ROC values of 0.631 (95%CI: 0.606-0.655), 0.653 (0.626-0.679), 0.753 (0.730-0.777), 0.784 (0.762-0.806), 0.766 (0.744-0.789) respectively.

Conclusion

Our study found that the accuracy of COPD screening by COPD-SQ questionnaire and COPD-PS questionnaire can be improved by combining the results of PEF. The screening performance of COPD-SQ questionnaire combined with PEF is relatively better. In future research, further studies are needed to optimize the performance of screening tools and understand whether their use will affect clinical outcomes.