Figures
- Fig. 1—
Changes in primary outcomes of the following: a) 6-minute walking distance, b) quadriceps strength, c) St George's Respiratory Questionnaire total and d) depression.
Tables
- Table 1—
Baseline characteristics by disease severity
Subjects n Disease severity p-value Mild (MRC grade 1/2)# Moderate (MRC grade 2/3)¶ Severe (MRC grade 5)+ Age yrs 74 63.6±11.4 67.9±9.6 73.2±7.9 0.005 BMI kg·m−2§ 74 26.3±5.2 29.2±8.7 25.8±5.5 ns Smoking pack-yrs§ 73 38.1±28.0 48.8±39.3 51.7±30.9 ns 6MWD % pred 73 71.3±14.2 50.2±18.2 27.7±15.8 <0.0001 Quadriceps torque (Nms/kg×100) 74 123.5±35.5 123.0±55.0 83.9±36.8 0.003 SGRQ score§ 74 38.0±14.8 61.2±12.9 65.5±14.2 <0.0001 FEV1 % pred 73 65.7±20.0 43.0±24.4 38.1±16.9 <0.0001 FVC % pred 73 83.7±20.7 65.6±19.7 66.4±23.8 0.008 MIP % pred 66 74.4±35.8 72.2±31.6 59.4±19.3 ns MEP % pred 66 98.2±44.0 87.9±32.1 77.4±34.6 ns V′O2,max kg·L−1·min−1 71 16.2±7.0 10.9±6.0 7.1±1.9 <0.0001 Grip % pred 74 109.9±17.6 102.6±24.0 99.3±25.1 ns Borg score pre-6MWD m§ 72 0.2±0.3 0.7±0.7 1.0±1.1 0.009 Borg score post-6MWD m§ 72 3.1±1.4 3.7±0.9 4.5±1.5 0.002 Sa,O2 pre-6MWD % 73 95.9±2.1 93.8±3.0 92.5±3.3 0.001 Sa,O2 post-6MWD % 73 94.5±3.8 91.0±6.2 88.5±6.2 0.003 COPDSE 72 3.4±1.0 2.9±0.9 2.7±0.9 0.03 LCADL§ 74 19.3±10.4 33.6±14.3 46.2±16.4 <0.0001 Differences were tested using ANOVA. Data are presented as mean (sd). A high score indicates better health, unless otherwise indicated (§: low score = better health). MRC: Medical Research Council; BMI: body mass index; 6MWD: 6-minute walk distance; SGRQ: St George's Respiratory Questionnaire; FEV1: forced expiratory volume in one second; % pred: per cent predicted; FVC: forced vital capacity; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure; V′O2,max: maximal oxygen consumption; Sa,O2: arterial oxygen saturation; COPDSE: Chronic Obstructive Pulmonary Disease Self-Efficacy Scale; LCADL: London Chest Activity of Daily Living Scale. #: n = 21; ¶: n = 29; +: n = 24; ns: nonsignificant.
- Table 2—
Changes in health following pulmonary rehabilitation for patients with mild, moderate or severe disease
Subjects n Disease severity p-value Mild (MRC grade 1/2) Moderate (MRC grade 2/3) Severe (MRC grade 5) 6MWD % pred of normative values 51 7.8±6.5 10.0±11.3 5.2±11.9 0.003 6MWD m 51 54.7±45.0 68.0±74.2 32.6±74.8 0.002 Quadriceps torque Nms 51 1.6±19.6 3.1±33.8 6.5±18.7 ns SGRQ score# 51 -7.5±10.3 -7.0±8.4 0.7±11.2 0.03 MIP % pred 48 11.1±22.9 2.7±10.3 1.9±10.5 ns MEP % pred 49 -0.0±22.7 10.1±17.9 11.3±31.5 ns Grip % pred 51 -0.9±11.4 3.1±12.3 -0.6±19.8 ns COPDSE 49 0.4±0.5 0.1±0.9 0.1±0.7 ns LCADL# 51 -0.4±3.9 -1.1±7.5 0.7±8.5 ns Data are presented as mean difference±sd between follow-up and baseline. A positive score = improvement, unless otherwise indicated (#: negative score = improvement). p-values represent the significance of disease severity in a generalised linear model with score at follow-up as the dependent variable, disease severity as the independent variable and baseline score as a covariate (nonsignificant (ns) = p>0.05). MRC: Medical Research Council; 6MWD: 6-minute walk distance; SGRQ = St George's Respiratory Questionnaire; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure; COPDSE: Chronic Obstructive Pulmonary Disease Self-Efficacy Scale; LCADL: London Chest Activity of Daily Living Scale.
- Table 3—
Relationship between baseline variables and change in outcomes
Δ6MWD % ΔQuads ΔSGRQ Age yrs −0.1 −0.0 0.2 BMI kg·m−2 0.2 −0.2 −0.1 Smoking pack-yrs −0.1 0.1 0.0 6MWD % pred −0.3# −0.1 −0.4¶ Quadriceps maximum torque Nms −0.2 −0.1 −0.2 Quadriceps Nms·kg−1×100 −0.4¶ −0.1 −0.1 SGRQ total 0.2 −0.1 −0.0 FEV1 % pred −0.0 −0.4¶ −0.1 FVC % pred −0.1 −0.3 0.0 MIP % pred 0.1 −0.2 −0.2 MEP % pred −0.1 −0.2 −0.1 V′O2,max kg·L−1·min−1 −0.1 0.0 −0.2 MVV −0.0 −0.3 −0.2 MVV/V′E −0.2 0.2 −0.1 Grip % pred 0.0 −0.0 0.0 Borg score pre-6MWD m 0.2 0.1 0.1 Borg score post-6MWD m −0.2 0.1 0.2 Sa,O2 pre-6MWD % −0.4¶ −0.3 −0.2 Sa,O2 post-6MWD % 0.1 −0.4¶ −0.2 Heart rate pre-6MWD −0.4¶ −0.1 0.1 Heart rate post-6MWD −0.3 0.1 0.0 COPDSE −0.3# 0.1 −0.0 LCADL 0.2 0.0 0.2 6MWD: 6-minute walking distance; SGRQ: St George's Respiratory Questionnaire; BMI: body mass index; FEV1: forced expiratory volume in one second; % pred: per cent predicted; FVC: forced vital capacity; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure; V′O2,max: maximum oxygen consumption; MVV/V′E: maximal voluntary ventilation/ventilation ratio; Sa,O2: arterial oxygen saturation; COPDSE: Chronic Obstructive Pulmonary Disease Self-Efficacy Scale; LCADL: London Chest Activity of Daily Living Scale. Borg pre-6MWD values were log transformed in order to achieve a normal distribution prior to analysis. #: p<0.05; ¶: p≤0.01.
- Table 4—
Percentage of patients completing pulmonary rehabilitation with a clinically significant change in St George's Respiratory Questionnaire (SGRQ) score (reduction of ≥4 units) and 6-minute walking distance (6MWD; increase of ≥54 m) stratified by the Medical Research Council dyspnoea score (MRC) grade.
Total Disease severity Mild (MRC grade 1/2) Moderate (MRC grade 2/3) Severe (MRC grade 5) Subjects n 51 16 22 13 6MWD ≥54 m 47 81 59 46 SGRQ score# ≥4 units 63 50 50 39 Composite responders 77 88 82 54 Data are presented as % or n. There was no difference between the groups in the number of patients who had changed significantly (p>0.05). Composite: percentage of patients completing pulmonary rehabilitation with a clinically significant change in either SGRQ score (a reduction of ≥4 units) or 6MWD (an increase of ≥54 m) stratified by MRC grade.
