Differences in outcomes between GOLD groups in patients with COPD in the TIOSPIR® trial

Background: The aim of this study was to evaluate whether Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification could predict mortality risk factors and whether baseline treatment intensity would relate to mortality within each group, using data from TIOSPIR (R), the largest randomized clinical trial in COPD performed to date. Methods: A total of 17,135 patients from TIOSPIR (R) were pooled and grouped by GOLD grading (A-D) according to baseline Medical Research Council breathlessness score, exacerbation history, and spirometry. All-cause mortality and adjudicated cardiovascular (CV) and respiratory mortality were assessed. Results: Of the 16,326 patients classified, 1,248 died on treatment. Group B patients received proportionally more CV treatment at baseline. CV mortality risk, but not all-cause mortality risk, was significantly higher in Group B than Group C patients (CV mortality - hazard ratio [HR] = 1.74, P = 0.004; all-cause mortality - HR = 1.18, P = 0.11). Group D patients had a higher incidence of all-cause mortality than Group B patients (10.9% vs 6.6%). Similar trends were observed regardless of respiratory or CV medication at baseline. In contrast, respiratory deaths increased consistently from Groups A-D (0.3%, 0.8%, 1.6%, and 4.2% of patients, respectively). Conclusion: The data obtained from the TIOSPIR (R) trial, supporting earlier studies, suggest that proportionally more CV medication and CV deaths occur in GOLD Group B COPD patients, although deaths attributed to respiratory causes are more prevalent in Groups C and D.