Mid-Term Effects of Pulmonary Rehabilitation on Cognitive Function in People with Severe Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Demographic Characteristics of the Patients

Characteristics	Patients			Between-Group Comparison
	Total (n = 56)	MoCA <26 (n = 41)	MoCA ≥26 (n = 15)	p
Gender, n female (%)	30 (54)	20 (49)	10 (67)	0.37
Age (yr), mean (SD)	62 (9)	64 (9)	59 (11)	0.13
Body mass index (kg/m^2), mean (SD)	24.5 (5.2)	25 (5.5)	23.3 (4.2)	0.29
FEV1 (L), median (IQR)	0.9 (0.7 to 1.1)	0.9 (0.6 to 1.2)	1.0 (0.7 to 1.1)	0.62
FEV1 (%), median (IQR)	36 (28 to 44)	36 (28 to 44)	39 (32 to 44)	0.56
FVC (L), median (IQR)	2.3 (1.7 to 2.7)	2.2 (1.6 to 2.7)	2.3 (2.1 to 3.6)	0.36
FEV1/FVC (%), mean (SD)	41 (10)	41 (10)	40 (9)	0.85
Residual volume (L), mean (SD)	4.1 (1.3)	4.2 (1.3)	3.8 (1.2)	0.35
TLC (L), mean (SD)	6.6 (1.4)	6.7 (1.4)	6.4 (1.5)	0.52
VO2peak (mL/kg/min), mean (SD)	12 (3)	12 (3)	14 (3)	0.06
Wpeak (W), median (IQR)	50 (39 to 63)	45 (36 to 60)	55 (39 to 73)	0.17
6MST (steps), median (IQR)	179 (113 to 209)	148 (103 to 202)	191 (156 to 246)	0.08
6MWT (meters), mean (SD)	386 (115)	377 (117)	409 (112)	0.39
BODE index, mean (SD)	5 (2)	5 (2)	4 (1)	0.09
Long-term oxygen, n (%)	27 (48)	22 (54)	5 (33)	0.23
Home non-invasive ventilation, n (%)	7 (13)	6 (15)	1 (7)	0.66
HAD-Anxiety, mean (SD)	10 (4)	10 (4)	9 (5)	0.42
HAD-Depression, median (SD)	8 (5 to 10)	8 (6 to 9)	6 (4 to 11)	0.50
Saint Georges Respiratory Questionnaire (%), mean (SD)	58 (16)	62 (15)	46 (15)	< 0.01
MoCA, median (IQR)	22 (20 to 26)	21 (20 to 24)	27 (26 to 28)	<0.01
Educational level^a				0.01
Level I, n (%)	1 (2)	1 (2)	0 (0)
Level II, n (%)	5 (9)	1 (2)	4 (27)
Level III, n (%)	2 (4)	1 (2)	1 (7)
Level IV, n (%)	8 (14)	4 (10)	4 (27)
Level V, n (%)	17 (30)	14 (34)	3 (20)
Level VI, n (%)	23 (41)	20 (49)	3 (20)
Comorbidities
Hypertension, n (%)	20 (36)	15 (37)	5 (33)	1.00
Hypercholesterolemia, n (%)	10 (18)	9 (22)	1 (7)	0.26
Diabetes, n (%)	4 (7)	1 (2)	3 (20)	0.06
Cardiopathies, n (%)	10 (18)	8 (20)	2 (13)	0.71
Surgery for NSCLC, n (%)	7 (13)	5 (12)	2 (13)	1.00
History of other cancer, n (%)	7 (13)	5 (12)	2 (13)	1.00

Notes: Fisher test for categorical data. Mann–Whitney or independent t-test for other characteristics. Percentages may not sum to 100 due to rounding. ^aEducational level was assessed according to the French National Institute of Statistics and Economic Studies Classification. Educational level ranged from I (Msc and higher) to V (interruption of the schooling during the first cycle of secondary education (before 16 years)).

Abbreviations: FEV₁, forced expiratory volume in 1 s; FVC, forced vital capacity; TLC, total lung capacity; VO_2peak, maximal oxygen consumption; W_peak, maximal workload achieved during cardiopulmonary exercise testing; 6MST, six-minute stepper test; 6MWT, six-minute walk test; BODE, body-mass index; obstructive; dyspnea and exercise capacity index; HAD, anxiety and depression scale; MoCA, Montreal Cognitive Assessment tool; NSCLC, non-small-cell lung cancer.

Figure 1 Study flow diagram.

Figure 2 Evolution of the Montreal Cognitive Assessment tool total score (A) and sub-score (B). Data are shown as median (25th–75th percentile). Friedman test and Wilcoxon as a post hoc test for pairwise comparison for within-group comparison. Baseline: n=56; following PR: n=37, 3 months following PR: n=22. *p<0.01 **p=0.04.

Table 2 Change in Secondary Outcomes Following and 3 Months After PR

Outcome	Timepoint			Within Group
	Baseline (n = 56)	Following PR (n = 37)	3 Months After PR (n = 22)	p
6MST (steps), median (IQR)	179 (113–209)	183 (160 to 273)		<0.01
Baseline MoCA <26	148 (103 to 202)	182 (121 to 310)		<0.01
Baseline MoCA ≥26	191 (156 to 246)	218 (162 to 263)		0.03
Between group p	0.08	0.03
6MWT (meters), mean (SD)	386 (115)	418 (108)		0.01
Baseline MoCA <26	377 (117)	405 (116)		0.10
Baseline MoCA ≥26	409 (112)	443 (88)		0.08
Between group p	0.39	0.37
HAD-Anxiety, mean (SD)	10 (4)	8 (4)	8 (4)	0.59
Baseline MoCA <26	10 (4)	9 (4)	9 (4)	0.67
Baseline MoCA ≥26	9 (5)	7 (3)	6 (3)	0.68
Between group p	0.42	0.12	0.14
HAD-Depression, mean (SD)	8 (3)	7 (4)	6 (3)	0.17
Baseline MoCA <26	8 (3)	7 (4)	7 (4)	0.45
Baseline MoCA ≥26	7 (4)	6 (4)	6 (3)	0.78
Between group p	0.53	0.62	0.79
SGRQ (%) – total score, mean (SD)	58 (16)	51 (14)	51 (14)	0.11
Baseline MoCA <26	62 (15)	53 (13)	54 (14)	0.11
Baseline MoCA ≥26	46 (15)	47 (15)	41 (12)	0.47
Between group p	< 0.01	0.19	0.09
SGRQ (%) – symptom sub-score, mean (SD)	54 (22)	50 (20)	47 (20)	0.57
Baseline MoCA <26	56 (21)	46 (21)	48 (21)	0.73
Baseline MoCA ≥26	50 (24)	57 (17)	43 (18)	0.95
Between group p	0.35	0.14	0.66
SGRQ (%) – activity sub-score, median (IQR)	77 (60 to 91)	73 (56 to 86)	73 (60 to 86)	0.85
Baseline MoCA <26	80 (65 to 93)	73 (60 to 86)	74 (61 to 86)	0.51
Baseline MoCA ≥26	65 (52 to 81)	66 (54 to 80)	60 (57 to 76)	0.54
Between group p	0.02	0.17	0.09
SGRQ (%) – impact sub-score, median (IQR)	46 (39 to 62)	43 (24 to 55)*	39 (32 to 46)*ǂ	0.02
Baseline MoCA <26	51 (42 to 66)	45 (33 to 56)	43 (33 to 47)*	0.03
Baseline MoCA ≥26	39 (20 to 46)	33 (15 to 54)	37 (11 to 39)	0.73
Between groups p	<0.01	0.13	0.09

Notes: Repeated ANOVA and Tukey post hoc tests or Friedman test and Wilcoxon as a post hoc test for pairwise comparison for within-group comparison. Mann–Whitney or independent t-test for between-group comparison. *Significantly different from baseline, p<0.05. ǂSignificantly different from following PR, p<0.05

Abbreviations: PR, pulmonary rehabilitation; 6MST, six-minute stepper test; 6MWT, six-minute walk test; HAD, anxiety and depression scale; SGRQ, Saint Georges Respiratory Questionnaire.