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The following is a summary of “CAD-Q (COPD-Asthma Differentiation Questionnaire): Performance of a new diagnostic score to differentiate between COPD and asthma in adults,” published in the January 2025 issue of Pulmonology by Lozano-Forero et al. 

Chronic obstructive pulmonary disease (COPD) and asthma are 2 prevalent chronic respiratory diseases with significant public health implications.  

Researchers conducted a retrospective study to develop the COPD-Asthma Differentiation Questionnaire (CAD-Q) for differentiating in adults between COPD and asthma.  

They performed diagnostic test analysis to identify clinical variables for diagnosing COPD and asthma. Crude Odds Ratios (OR) were used, and a logistic regression model provided adjusted ORs. The CAD-Q was compared to the Lung Function Questionnaire (LFQ), COPD Diagnostic Questionnaire (CDQ), Pneumonia and COPD Assessment (PUMA), “Could it be COPD,” and COPD Population Screener questionnaire (COPD-PS) questionnaires using sensitivity, specificity, predictive values, likelihood ratios, and the ROC-curve.  

The results showed that 235 (52.9%) participants had COPD and 209 (47.1%) had asthma. A CAD-Q score ≥ 20 yielded a ROC-curve of 70% (95% CI: 65–75; P < 0.001), with a sensitivity of 83.8% (95% CI: 81.1–86.6), specificity of 47.8% (95% CI: 44.1–51.6), positive predictive value of 37.8% (95% CI: 34.2–41.5), negative predictive value of 88.7% (95% CI: 86.3–91), LR+ of 1.61 (95% CI: 1.447–1.786), and negative likelihood ratio (LR−) of 0.34 (95% CI: 0.304–0.376) for diagnosing COPD. Compared with other questionnaires, CAD-Q and CDQ showed the highest sensitivity (83.8% and 77.9%), while PUMA and “Could it be COPD” had the highest specificity (62.7% and 62.6%). The CAD-Q and COPD-PS demonstrated the highest negative predictive values (88.7% and 62.1%), and CAD-Q, LFQ, and CDQ exhibited the highest ROC-curve (70%, 66%, and 66%).  

Investigators concluded the CAD-Q questionnaire effectively differentiated between COPD and asthma, outperforming the performance of previous diagnostic tools. 

Source: bmcpulmmed.biomedcentral.com/articles/10.1186/s12890-025-03492-5