Health status instruments predict exacerbations of COPD: findings from the prospective TIE cohort study

Aim Identifying patients at risk for acute exacerbations of COPD (AECOPDs) is crucial to improve outcomes. We aimed to evaluate the ability of three health status instruments to predict AECOPDs. Methods A prospective cohort study of COPD patients. AECOPDs were retrieved from medical records one year before inclusion until three years after. Instruments evaluated were the modified Medical Research Council Dyspnoea scale (mMRC), the COPD Assessment Test (CAT) and the Clinical COPD Questionnaire (CCQ). Thresholds for the prediction of AECOPDs were estimated using receiver operator characteristic curves. The predictive value of each instrument and combinations of instruments were assessed by crude and multivariable Cox regression models. Results In total, 572 patients (59% women, age 69 ± 8 years, FEV₁ 57 ± 18% of predicted) were included in 2014–2016. Optimal thresholds for predicting AECOPDs were estimated to be ≥ 2 for mMRC, ≥ 13 for CAT and ≥ 1.55 for CCQ. The adjusted HR (aHR) for a future AECOPD was 1.5 (95% confidence interval 1.2-2.0) for mMRC, 1.8 (1.3–2.3) for CAT, and 1.6 (1.2–2.1) for CCQ if scores were above the thresholds. When combining instruments, the aHR for a future AECOPD was 1.5 (1.0-2.3), 1.7 (1.1–2.5) and 2.1 (1.5-3.0) for one, two and three instruments above the thresholds, respectively. For ≥ 1 AECOPD during the year before inclusion, the aHR for a future AECOPD was 2.7 (2.1–3.5). Conclusion mMRC, CAT, and CCQ independently predicted AECOPDs. Combining the instruments improved the predictive value.