Predictive value of control of COPD for risk of exacerbations: An international, prospective study

Background and objective: The concept of clinical control in COPD has been developed to help in treatment decisions, but it requires validation in prospective studies. Methods: This international, multicentre, prospective study aimed to validate the concept of control in COPD. Patients with COPD were classified as controlled/uncontrolled by clinical criteria or CAT scores at baseline and followed up for 18 months. The main outcome was the difference in rate of a composite endpoint of moderate and severe exacerbations or death over the 18-month follow-up period. Results: A total of 307 patients were analysed (mean age = 68.6 years and mean FEV₁% = 52.5%). Up to 65% and 37.9% of patients were classified as controlled by clinical criteria or CAT, respectively. Controlled patients had significantly less exacerbations during follow-up (by clinical criteria: 1.1 vs 2.6, P < 0.001; by CAT: 1.1 vs 1.9, P = 0.014). Time to first exacerbation was significantly prolonged for patients controlled by clinical criteria only (median: 93 days, IQR: 63; 242 vs 274 days, IQR: 221; 497 days; P < 0.001). Control status by clinical criteria was a better predictor of exacerbations compared to CAT criteria (AUC: 0.67 vs 0.57). Conclusion: Control status, defined by easy-to-obtain clinical criteria, is predictive of future exacerbation risk and time to the next exacerbation. The concept of control can be used in clinical practice at each clinical visit as a complement to the current recommendations of initial treatment proposed by guidelines.