Exacerbation Risk and Mortality in Global Initiative for Chronic Obstructive Lung Disease Group A and B Patients with and without Exacerbation History

Rationale: Risk stratification of patients according to chronic obstructive pulmonary disease severity is clinically important and forms the basis of therapeutic recommendations. No studies have examined the association for Global Initiative for Chronic Obstructive Lung Disease (GOLD) group A and group B patients with (A1 and B1, respectively) and without (A0 and B0, respectively) an exacerbation in the past year with future exacerbations, hospitalizations, and mortality in perspective with the new GOLD ABE classification. Objectives: The aim was to examine the association between GOLD A0, A1, B0, B1, and E patients and future exacerbations, respiratory and cardiovascular hospitalizations, and mortality. Methods: In this nationwide cohort study, we identified patients with a diagnosis of chronic obstructive pulmonary disease, aged ⩾30 years, and registered in the Swedish National Airway Register between January 2017 and August 2020. Patients were stratified in GOLD groups A0, A1, B0, B1, and E and were followed until January 2021 for exacerbations, hospitalizations, and mortality in national registries. Measurements and Main Results: The 45,350 eligible patients included 25% A0, 4% A1, 44% B0, 10% B1, and 17% E. Moderate exacerbations, all-cause and respiratory hospitalizations, and all-cause and respiratory mortality increased by GOLD group A0-A1-B0-B1-E, except for moderate exacerbations, which were higher in A1 than in B0. Group B1 had a substantially higher hazard ratio for future exacerbation (2.56; 95% confidence interval [95% CI] 2.40-2.74), all-cause hospitalization (1.28; 1.21-1.35), and respiratory hospitalization (1.44; 1.27-1.62), but not all-cause (1.04; 0.91-1.18) or respiratory (1.13; 0.79-1.64) mortality than group B0. The exacerbation rate for group B1 was 0.6 events per patient-year versus 0.2 for group B0 (rate ratio, 2.55; 95% CI, 2.36-2.76). Results were similar for group A1 versus group A0. Conclusions: Stratification of GOLD A and B patients with one or no exacerbation in the past year provides valuable information on future risk, which should influence treatment recommendations for preventive strategies.