Abstract
Introduction: Patients with higher of Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages (III or IV) or past frequency of exacerbations (> 2/year)/hospitalizations (>1/year) are categorized into group D in the 2011 GOLD classification. As spirometry is known to poorly predict the risk of exacerbations, we hypothesized that patients categorized by these criteria differ in clinical characteristics and risk predictions.
Methods: Disease severity was classified in 400 COPD patients using modified Medical Research Council (mMRC) grading of dyspnoea and COPD Assessment Test (CAT) followed by spirometry. Group D patients were sub-grouped based on categorization by GOLD stages (D1), exacerbation history (D2) and by both criteria (D3). ADO (Age, Dyspnea, Obstruction) index was computed as a predictor of all-cause mortality risk.
Results: Group D (n=249) were sub-grouped into D1 (131-52.6%), D2 (48-19.3%) and D3 (70-28.1%). Age, gender distribution, body mass index, smoking and comorbidities did not differ among these. CAT scores among D1 patients (17.6±6.9) were lower than the others (D2: 22.2±6.7 and D3: 23.9±7.3) (p<0.0001). Post-bronchodilator lung function was lower in groups D1 and D3 compared to D2 (p<0.0001). D3 subgroup had more patients with higher grades of dyspnea. ADO index scores were higher in groups D1 and D3 compared to D2 (p<0.0001).
Conclusions: Patients with frequent exacerbations have poorer health status despite a better lung function. They however have a lower all-cause mortality risk compared to the other subgroups. Thus, with patients differing in clinical characteristics and risk predictions, group D of the new GOLD classification is not homogenous which has therapeutic implications.
- Copyright ©the authors 2016
