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.