Characteristics, stability and outcomes of the 2011 GOLD COPD groups in the ECLIPSE cohort

Abstract

The 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) classifies patients with chronic obstructive pulmonary disease (COPD) into four groups (A to D).We explored the characteristics, stability and relationship to outcomes of these groups within the ECLIPSE study (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points) (n52101).Main results showed that: 1) these groups differed in several clinical, functional, imaging and biological characteristics in addition to those used for their own definition; 2) A and D groups were relatively stable over time, whereas groups B and C showed more temporal variability; 3) the risk of exacerbation over 3 years increased progressively from A to D, whereas that of hospitalisation and mortality were lowest in A, highest in D and intermediate and similar in B and C, despite the former having milder airflow limitation. The prevalence of comorbidities and persistent systemic inflammation were highest in group B.The different longitudinal behaviour of group A versus B and C versus D (each pair with similar forced expiratory volume in1 s (FEV1) values supports the 2011 GOLD proposal of assessing COPD patients by more than FEV1 only. However the assumption that symptoms do not equate to risk appears to be naïve, as groups B and C carry equally poor clinical outcomes, though for different reasons. @ERSpublications Exploring distribution, characteristics, temporal stability and relationship with 2011 GOLD group outcomes in ECLIPSE

Clinical and prognostic heterogeneity of C and D GOLD groups

“…Our results confirmed previous observations indicating that a FEV1 <50% reference alone (subgroups C1, D1) was the most frequent reason (∼75% of patients) to classify them as group C or D [2][3][4]. This may have therapeutic implications since some C1 and D1 subgroup patients may benefit, mostly, from bronchodilator therapy, whereas C2/C3 and D2/D3 subgroups are likely to benefit most from the addition of anti-inflammatory therapy to reduce the risk of future exacerbations [9].…”

“…groups C and D) [1] include: patients with a forced expiratory volume in 1 s FEV1 <50% reference and <2 exacerbations year -1 (subgroups C1 and D1); patients with ⩾2 exacerbations·year -1 and an FEV1 ⩾50% reference (subgroups C2 and D2); and patients with both FEV1 <50% ref. and ⩾2 exacerbations·year -1 (subgroups C3 and D3) [2][3][4][5]. We hypothesised that these high-risk subgroups will differ in other clinical, functional and biological characteristics and will be associated with different long-term outcomes.…”

“…The study was approved by the Ethics Committees from the participating centres and all participants signed their informed consent [7]. Out of the 2164 GOLD grades II-IV patients included in the ECLIPSE study, 2101 (97%) had complete GOLD 2011 data [4] and were included in the current analysis; 1313 of them (62.5%) were classified as groups C (n=483, 36.8%) or D (n=830, 63.2%), using the modified Medical Research Council dyspnoea score to determine high and low COPD symptoms.These analyses are exploratory and may have low power, since they are based on a subset of the COPD subjects enrolled in ECLIPSE. Results are shown as mean±SD or n (%), as appropriate.…”

“…No adjustments were made for multiple comparisons. SAS (version 9; SAS Institute, Inc., Cary, NC, USA) was used to conduct all analyses and figures were created via S-PLUS (TIBCO Software, Boston, MA, USA).On the one hand, from the 483 group C patients, 336 (70%) 62 (13%) and 85 (18%) were classified in the subgroups C1, C2 and C3, respectively [4]. As expected, lung function was worse in subgroups C1 and C3 (both groups had clinically comparable airflow limitation), and exacerbations prior to the start of the study were more frequent in subgroups C2 and C3 (both groups had a comparable level of exacerbation history).…”

Addressing unmet needs in the treatment of COPD

“…Analysis of cohort data from four large studies [58][59][60][61] suggests that there is considerable variability between the prevalence of the four GOLD groups. Findings are influenced by the population involved.…”