The Impact of Loneliness on Outcomes of Pulmonary Rehabilitation in Patients with COPD

Figures & data

Table 1. Baseline sample characteristics.

Variables	Results
Age (years)	57.6 (7.7)
Sex (female/male)	31/73
Weight (kg)	81.9 (23.4)
Height (cm)	172.6 (8)
BMI	27.2 (7.0)
FEV1 (% predicted)	45 (14)
FEV1 (L)	1.43 (0.52)
VC (% predicted)	74 (15)
VC (L)	3.03 (0.85)
FEV1/ VC (%)	48 (12)
GOLD stage n (%)
I	0 (0)
II	47 (45)
III	41 (40)
IV	16 (15)
Depression n (%)	31 (30)
Anxiety n (%)	25 (24)
Loneliness – total score n (%)
None	55 (52)
Moderate	36 (35)
Severe	11 (11)
Very severe	2 (2)
Active smoker n (%)	39 (38)
Former smoker n (%)	60 (58)
Never smoker n (%)	5 (5)

Data are presented as mean (SD) unless otherwise indicated. BMI: Body Mass Index; FEV1: Forced Expiratory Volume in 1 second; VC: Vital Capacity; GOLD: Global Initiative for Chronic Obstructive Lung Disease.

Table 2. Mean (SD) outcome measures at the start and end of PR.

Outcome	Start of PR	End of PR	p Value
6MWD (m)	427.1 (111.9)	513.5 (112.1)	<.001
HQoL (mental)	47.4 (12.2)	50.4 (11.2)	<.01
HQoL (physical)	35.3 (9.0)	37.8 (9.2)	<.001
Depression (PHQ-9)	7.2 (5.4)	5.3 (5.0)	<.001
Anxiety (GAD-7)	6.1 (5.0)	4.6 (4.5)	<.001

6MWD: 6-min walking distance; GAD-7: Generalized Anxiety Disorder-7; HQoL: health-related quality of life; PHQ-9: Patient Health Questionnaire-9.

Figure 1. Impact of emotional loneliness on outcomes at the start of PR. (A) Association of emotional loneliness with functional capacity at the start of PR. (B) Association of emotional loneliness with quality of life at the start of PR. (C) Association of emotional loneliness with depression at the start of PR. (D) Association of emotional loneliness with anxiety at the start of PR.

Table 3. Association of emotional loneliness with outcome measures at the start of PR.

Outcome	B	SE	β	R²	ΔR²	p Value
6MWD (m)	−3.91	1.94	−0.19	0.22	0.03	.046
HQoL (mental)	−1.32	0.19	−0.58	0.37	0.31	<.001
HQoL (physical)	−0.08	0.17	−0.05	0.11	0.00	.63
Depression	0.61	0.08	0.59	0.47	0.33	<.001
Anxiety	0.51	0.08	0.55	0.37	0.29	<.001

Results from hierarchical regression analyses for the association between emotional loneliness and PR outcomes at the start of PR, after controlling for age, sex, FEV1%predicted, and smoking status.

6MWD: 6-min walking distance; HQoL: health-related quality of life.

Figure 2. Impact of changes in emotional loneliness on changes in outcomes of PR. (A) Association of changes in emotional loneliness with changes in functional capacity over the course of PR. *Excluding the outlier patient did not change the results. (B) Association of changes in emotional loneliness with changes in quality of life over the course of PR. *Excluding the outlier patient did not change the results.

Table 4. Association of emotional loneliness at the start of PR with changes in outcome measures during PR.

Outcome (post-PR–pre-PR)	B	SE	β	R²	ΔR²	p Value
6MWD (m)	3.06	1.25	0.25	0.09	0.07	.016
HQoL (mental)	0.41	0.19	0.22	0.09	0.04	.032
HQoL (physical)	−0.01	0.13	−0.01	0.04	0.00	.940
Depression	−0.11	0.08	−0.13	0.07	0.02	.188
Anxiety	−0.10	0.07	−0.14	0.08	0.02	.158

Results from hierarchical regression for the association between emotional loneliness at the start of PR and changes (post-PR–pre-PR) in PR outcomes, after controlling for age, sex, FEV1%predicted, and smoking status.

6MWD: 6-min walking distance; HQoL: health-related quality of life.

Table 5. Association of changes in emotional loneliness with changes in outcome measures during PR.

Outcome (post-PR–pre-PR)	B	SE	β	R²	ΔR²	p Value
6MWD (m)	−4.21	1.68	−0.25	0.09	0.06	.014
HQoL (mental)	−0.65	0.25	−0.25	0.10	0.06	.012
HQoL (physical)	0.06	0.17	0.04	0.02	0.00	.730
Depression	0.12	0.11	0.11	0.06	0.01	.294
Anxiety	−0.04	0.10	−0.04	0.05	0.00	.681

Results from hierarchical regression for the association between changes (post-PR–pre-PR) in emotional loneliness and changes (post-PR–pre-PR) in PR outcomes, after controlling for age, sex, FEV1%predicted, and smoking status.

6MWD: 6-min walking distance; HQoL: health-related quality of life.