Table 1– Outcomes of the four groups of patients as per the 2011 Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations [2].
Distribution2011 GOLD groupsp-value
ABCD
Patients495 (24)293 (14)483 (23)830 (40)
GOLD 2011 assessment variables
 mMRC dyspnoea score0.6±0.52.3±0.60.8±0.42.6±0.7<0.001
 FEV1 % predicted64.2±8.161.6±8.242.2±11.537.2±11.2<0.001
 Exacerbations previous 12 months0.2±0.40.3±0.51.0±1.41.3±1.4<0.001
Demographics
 Age years63.2±7.264.1±7.362.9±7.263.6±6.90.078
 Female191(39)106(36)149(31)280(34)0.07
 Body mass index kg·m−226.7±4.828.5±6.125.2±4.926.5±6.1<0.001
 Fat-free mass index kg·m−217.3±2.518.0±3.516.7±2.517.1±2.9<0.001
 Smoking, pack-years48.0±29.447.5±25.845.2±23.251.1±27.7<0.001
 Current smoker188 (38)101 (34)207 (43)267 (32)0.001
Symptoms
 Chronic bronchitis131 (26)104 (35)182 (38)318 (38)<0.001
 SGRQ-C total score31.9±17.355.3±15.544.6±16.862.2±15.6<0.001
 CESD total score8.3±8.013.8±9.49.5±8.213.5±9.7<0.001
Self-reported comorbidities
 With any comorbidity383 (77)248 (85)350 (72)690 (83)<0.001
 Number of comorbidities2.0±1.72.8±2.21.7±1.72.3±1.9<0.001
Physiology
 FEV1 % reversibility11.4±13.211.8±12.910.3±13.510.2±14.50.035
SaO2 %95.7±2.195.1±2.594.4±3.293.7±3.2<0.001
 6-min walking distance m440±106360±101408±106307±114<0.001
 BODE index0.8±0.82.7±1.22.6 (1.25.1±1.6<0.001
Imaging
% LAA -950 HU11.8±9.712.5±9.918.9±11.522.5±12.8<0.001
Outcomes during 3-year follow-up
 ECOPD per year0.6±0.80.9±1.01.3±1.41.7±1.7<0.001
 ≥1 hospitalisation56 (11)71 (25)143 (30)378 (46)<0.001
 Mortality rate22 (4)28 (10)41 (8)114 (14)<0.001
 Mortality rate per 100 patient-years1.6±7.43.7±11.53.2±10.55.5±13.7<0.001
 Rate of annual FEV1 decline mL per year-33.4 (46.2)-38.0 (47.0)-30.2 (45.5)-31.9 (34.6)0.157
  • Data are presented as n (%) or mean±sd, unless otherwise stated. mMRC: dyspnoea score according to the modified Medical Research Council questionnaire; FEV1; forced expiratory volume in 1 s; SGRQ-C: St George’s Respiratory Questionnaire for chronic obstructive pulmonary disease (COPD) patients; CESD: Center for Epidemiological Studies Depression Scale; SaO2; arterial oxygen saturation; BODE: body mass index, airflow obstruction, dyspnoea, exercise capacity index; % LAA: percentage of low attenuation areas (i.e. emphysema) in the computed tomography; ECOPD: exacerbation of COPD.