Simple screening tools feasible for identifying COPD in low- and middle-income countries

Screening tools that use questionnaires and peak expiratory flow were feasible for identifying COPD in low- and middle-income countries, researchers reported in JAMA.

“In low- and middle-income countries, where the majority of burden of COPD can be found, simple screening tools — like the ones we tested — can have an important impact in identifying people with COPD, and then getting them to start getting appropriately referred for management,” William Checkley, MD, PhD, associate professor of medicine in the division of pulmonary and critical care at Johns Hopkins School of Medicine and director of the Center for Global Non-Communicable Disease Research and Training at Johns Hopkins University, told Healio. “A challenge in many low- and middle-income countries is the availability of physicians and equipment to diagnose COPD and identify those people that are at greatest risk of having COPD.”

The researchers conducted a cross-sectional analysis to evaluate the discriminative accuracy of three instruments to screen for COPD. The study was conducted from January 2018 to March 2020 in three locations: semi-urban Bhaktapur, Nepal; urban Lima, Peru; and rural Nakaseke, Uganda. The three screening tools were the COPD Assessment in Primary Care to Identify Undiagnosed Respiratory Disease and Exacerbation Risk (CAPTURE), the COPD in Low- and Middle-Income Countries Assessment questionnaire (COLA-6) and the Lung Function Questionnaire (LFQ), which were assessed against a reference standard COPD diagnosis using quality-assured postbronchodilator spirometry. The CAPTURE and COLA-6 tools also include a measure of peak expiratory flow.

The primary outcome was the discriminative accuracy of the three screening tools to identify COPD. The researchers also assessed secondary outcomes including sensitivity, specificity, and positive and negative predictive values.

In the three countries, 10,709 adults aged 40 years and older participated in the study. The mean age was 56.3 years and 50% were women. One-third reported a history of ever smoking and 30% reported current exposure to biomass smoke.

The unweighted prevalence of COPD was 18.2% in semi-urban Nepal, 2.7% in urban Peru and 7.4% in rural Uganda.

One thousand COPD cases were identified. Of those, 49.3% of those with COPD had clinically important disease, defined as a Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) classification of B-D; 16.4% had severe or very severe airflow obstruction, with an FEV₁ of less than 50% predicted; and 95.3% were previously undiagnosed, the researchers reported.

The area under the curve for the screening tools ranged from 0.717 for the LFQ in Peru to 0.791 for COLA-6 in Nepal. Sensitivity ranged from 34.8% for COLA-6 in Nepal to 64.2% for CAPTURE in Nepal, according to the results.

Mean time to administration of the screening tool was 7.6 minutes. Complete data were captured for 99.5% of participants.

”Even in settings where there is a wide range of COPD prevalence, the screening tools were effective in identifying a large proportion of the cases that eventually developed COPD,” Checkley told Healio. Further, the researchers found good discrimination using these questionnaires compared with the gold standard of spirometry, Checkley said.

The researchers highlighted a need for further research to assess performance of these instruments in other low- and middle-income areas and also to evaluate whether implementation of these tools is associated with improved outcomes.

For more information:

William Checkley, MD, PhD, can be reached at wcheckl1@jhmi.edu.