Prognostic Accuracy of Three COPD Classification Systems in Relation to Long-Term Mortality of COPD Patients: A Prospective Multicenter Study

Abstract

Recent research showed group B patients express higher mortality compared to group C patients when GOLD A-D grouping is used. We aimed to compare the prognostic accuracy of three GOLD classification systems, I–IV (“pre-2011”), A-D (“2011–2016”) and A-D (“2017–present”) in relation to mortality, exacerbation risk, quality of life (QoL) assessment and specific treatments use in a real-life COPD cohort. We used the data of 720 patients from the Czech Multicenter Research Database of COPD. Four-year mortality and time-to-exacerbation using the GOLD “pre-2011”, “2011–2016” and “2017–present” classification schemes were assessed. Moreover, distribution of specific treatments use and QoL measures were analyzed. The GOLD I-IV classification system showed gradual increase in 4-year mortality across the stages (GOLD II 18.8%, III 28.5%, IV 38.7%) (p = 0.001). Using the A-D “2011–2016” classification scheme, group C patients had lower mortality (16.7%) than group B (18.7%) (p = 0.009). The A-D “2017–present” classification showed higher mortality in group B (25.5%) compared to group C (20%) (p = 0.05). For additional outcomes, the GOLD I–IV scheme showed highest match between the calculated 4-year exacerbation risk and QoL measures and GOLD stage/grouping. In terms of specific treatment distributions, various patterns for each GOLD classification system were observed with best match of GOLD “2017–present” system to the layout of GOLD groups and categories. We conclude the GOLD I–IV classification system had the highest accuracy related to mortality, QoL measures and exacerbation risk prediction, while the A-D “2017–present” scheme was most accurate within severity of symptoms prediction reflected also by more frequent specific treatments use.