2011 GOLD Stages of COPD: Transitions, Predictor Factors and Comparison with 2017 GOLD Stages.

Background: Despite wide use of the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 2011, little is known about between-stage transitions and what factors predict worsening transitions in patients with chronic obstructive pulmonary disease (COPD). Objective: To investigate the transition frequency between GOLD 2011 stages among patients with stable COPD over a 2-year follow-up, to identify potential non-pulmonary predictor factors for worsening transitions, and to compare transition frequencies between GOLD 2011 stages and the new GOLD 2017 stages. Patients and Methods: We prospectively included 137 patients with stable COPD (mean age, 66.9 +/- 8.3 years). GOLD 2011 and GOLD 2017 stages were measured at baseline, 1-year follow-up, and 2-year follow-up. To evaluate non-pulmonary variables as potential predictors of worsening transitions, we used regression models adjusted for sociodemographic, clinical, and pulmonary variables using generalized estimating equations. Results: The study period included 246 opportunities for transition, and 39 worsening transitions occurred within GOLD 2011 stages. Predictors of worsening transitions included BODE index (OR, 1.20; 95% CI, 1.00-1.44), quadriceps strength (OR, 0.87; 95% CI, 0.76-0.99), and limited mobility activities (OR, 1.02; 95% CI, 1.00-1.05). The frequency of worsening transitions for stages B and C differed between GOLD 2011 and GOLD 2017. Stages A and D were the most stable in both classifications. Conclusion: Non-pulmonary factors predicted worsening transitions among the GOLD 2011 stages of COPD severity. The choice of GOLD 2011 versus GOLD 2017 may influence transition identification, especially for stages B and C.