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

Does the 2017 global initiative for chronic obstructive lung disease revision really improve the assessment of Chinese chronic obstructive pulmonary disease patients? A multicenter prospective study for more than 5 years

BACKGROUND

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 proposed a new classification that reclassified many chronic obstructive pulmonary disease (COPD) patients from group D to B. However, there is a paucity of data related to the comparison between reclassified and non-reclassified COPD patients in terms of long-term prognosis. This study aimed to investigate long-term outcomes of them and determine whether the GOLD 2017 revision improved the assessment of COPD patients.

METHODS

This observational, multicenter, prospective study recruited outpatients at 12 tertiary hospitals in China from November 2016 to February 2018 and followed them up until February 2022. All enrolled patients were classified into groups A to D based on GOLD 2017, and the subjects in group B included patients reclassified from group D to B (group DB) and those remaining in group B (group BB). Incidence rates and hazard ratios (HRs) were calculated for the exacerbation of COPD and hospitalization in each group.

RESULTS

We included and followed up 845 patients. During the first year of follow-up, the GOLD 2017 classification had a better discrimination ability for different risks of COPD exacerbation and hospitalization than GOLD 2013. Group DB was associated with a higher risk of moderate-to-severe exacerbation (HR = 1.88, 95% confidence interval [CI] = 1.37-2.59, P  <0.001) and hospitalization for COPD exacerbation (HR = 2.23, 95% CI = 1.29-3.85, P  = 0.004) than group BB. However, during the last year of follow-up, the differences in the risks of frequent exacerbations and hospitalizations between group DB and BB were not statistically significant (frequent exacerbations: HR = 1.02, 95% CI = 0.51-2.03, P  = 0.955; frequent hospitalizations: HR = 1.66, 95% CI = 0.58-4.78, P  = 0.348). The mortality rates of the two groups were both approximately 9.0% during the entire follow-up period.

CONCLUSIONS

The long-term prognosis of patients reclassified into group B and of those remaining in group B was similar, although patients reclassified from group D to group B had worse short-term outcomes. The GOLD 2017 revision could improve the assessment of Chinese COPD patients in terms of long-term prognosis.

Burden of Disease in Patients with Mild or Mild-to-Moderate Chronic Obstructive Pulmonary Disease (Global Initiative for Chronic Obstructive Lung Disease Group A or B): A Systematic Literature Review

Background

Patients with mild or mild-to-moderate chronic obstructive pulmonary disease (COPD), defined as Global Initiative for Chronic Obstructive Lung Disease (GOLD) group A/B, are regarded as having a lower risk of experiencing multiple or severe exacerbations compared with patients classified as GOLD group C/D. Current guidelines suggest that patients in GOLD A/B should commence treatment with a bronchodilator; however, some patients within this population who have a higher disease burden may benefit from earlier introduction of dual bronchodilator or inhaled corticosteroid-containing therapies. This study aimed to provide research-based insights into the burden of disease experienced by patients classified as GOLD A/B, and to identify characteristics associated with poorer outcomes.

Methods

A systematic literature review (SLR) was conducted to identify evidence (burden of disease and prevalence data) relating to the population of interest (patients with COPD classified as GOLD A/B).

Results

A total of 79 full-text publications and four conference abstracts were included. In general, the rates of moderate and severe exacerbations were higher among patients in GOLD group B than among those in group A. Among patients classified as GOLD A/B, the risk of exacerbation was higher in those with more symptoms (modified Medical Research Council or COPD Assessment Test scales) and more severe airflow limitation (forced expiratory volume in 1 second % predicted).

Conclusion

Data from this SLR provide clear evidence of a heavier burden of disease for patients in GOLD B, compared with those in GOLD A, and highlight factors associated with worse outcomes for patients in GOLD A/B.

Prognostic Properties of the GOLD 2023 Classification System

Introduction

Recently, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) has published an update on the Global Strategy for Prevention, Diagnosis and Management of COPD, introducing a new classification of chronic obstructive pulmonary disease (COPD). Our aim was to assess the prognostic value of the new GOLD classification system in comparison with the previous GOLD classification systems (GOLD stages I-IV and GOLD groups A-D) and the BODE index.

Methods

We used the data of 784 patients with COPD from the Czech Multicenter Research Database of COPD. Patient survival was analyzed with the use of Kaplan-Meier estimate and Cox model of proportional risks. ROC analysis and area under curve (AUC) were used for comparison of GOLD classifications and BODE index. The analyses were performed with the use of software R (version 4.2.0).

Results

We analyzed data of 782 patients with complete data on GOLD classifications. The study population comprised 72.9% of men, 89.1% current or former smokers, with a mean age of 66.6 years, a mean BMI of 27.4 and a mean FEV₁ 44.9% of predicted. Probability of 5-year survival differed by GOLD classification. Application of the 2023 GOLD classification showed increased risk of death in group B (HR 1.82, 95% CI 1.14-2.92; p = 0.013) and in group E (HR 2.48, 95% CI 1.54-3.99; p˂0.001). The ROC analysis showed that the overall prognostic value of the 2023 GOLD classification was similarly weak to previous A-D GOLD classification schemes (AUCs 0.557-0.576) and was lower compared to the GOLD 1-4 system (AUC 0.614) and even lower when compared to the BODE index (AUC 0.715).

Conclusion

We concluded that the new GOLD classification system has poor prognostic properties and that specific prediction tools (eg, the BODE index) should be used for mortality risk assessment.