Correlation between self-management, psychological cognitive impairment, and quality of life in elderly chronic obstructive pulmonary disease patients

Table 1 Total scores and scores for each dimension of self-management behaviors in elderly chronic obstructive pulmonary disease patients (n = 312)

Dimension	Entry	Minimum value	Maximum value	Median (P25, P75)
Total score of self-management level	51	92	237	136.00 (119.00, 164.50)
Symptom management	8	18	60	34.00 (30.00, 42.00)
Daily life management	14	18	68	31.00 (25.00, 41.75)
Emotional management	12	10	48	29.00 (26.00, 33.75)
Self-efficacy	9	11	44	25.00 (21.00, 31.00)
Information management	8	10	39	16.00 (14.00, 20.00)

Table 2 Status of cognitive frailty in elderly chronic obstructive pulmonary disease patients (n = 312)

Project	Dimension	Minimum value	Maximum value	Median (P25, P75)
Simple scale weakness score	5	0	5	3.00 (2.00, 3.75)
Mental state score	5	5	30	18.00 (16.00, 27.00)
Clinical dementia assessment score	6	0	3	0.50 (0.00, 1.00)

Table 3 Total scores and scores for each dimension of quality of life in elderly chronic obstructive pulmonary disease patients (n = 312)

Dimension	Minimum value	Maximum value	Median (P25, P75)
Total score of quality of life	8	38	24.00 (19.00, 28.00)
Degree of breathlessness when climbing stairs	1	5	5.00 (3.00, 5.00)
Tolerance for daily household activities	0	5	3.00 (3.00, 5.00)
Confidence level in outdoor activities	0	5	3.00 (3.00, 5.00)
Vitality	0	5	3.00 (3.00, 3.00)
Severity of coughing	0	5	3.00 (2.25, 3.00)
Total amount of phlegm coughed up	0	5	3.00 (2.00, 3.00)
Sleep condition	0	5	1.00 (0.00, 5.00)
Degree of chest tightness	0	4	0.00 (0.00, 2.00)

Table 4 Correlation between self-management level, cognitive frailty and total score of quality-of-life level in elderly chronic obstructive pulmonary disease patients

Variable	Total score of self-management	Onset of cognitive impairment	Simplified Weakness Score	Simplified Mental State Rating	Clinical Dementia Rating Scale Score	Total score of quality-of-life level
Total score of self-management level	1
Onset of cognitive impairment	-0.589c	1
Simplified Weakness Score	-0.373c	0.540c	1
Simplified Mental State Rating	0.247c	-0.126a	-0.254c	1
Clinical Dementia Rating Scale Score	-0.116a	-0.077	0.165b	-0.860c	1
Total score of quality-of-life level	-0.410c	0.345c	0.404c	-0.609c	0.592c	1

^aP< 0.05.

^bP< 0.01.

^cP< 0.001.

Table 5 Comparison of total scores of qualities of elderly chronic obstructive pulmonary disease patients with different demographic characteristics (n = 312)

Variable	Total score of quality of life, median (P25, P75)	Z/H value	P value
Age, years
60-69	23.00 (18.00, 28.00)	4.456	0.108
70-79	22.00 (18.00, 27.00)
80 and above	25.00 (20.75, 29.00)
Body mass index, kg/m2
< 18.5	24.00 (19.00, 29.00)	2.077	0.354
18.5-23.9	24.00 (18.00, 28.00)
≥ 24	22.00 (18.00, 27.00)
Gender
Male	24.00 (19.00, 28.00)	0.720	0.472
Female	22.50 (18.00, 28.75)
Degree of education
Elementary school and below	25.00 (19.00, 29.00)	7.370	0.025
Junior high school and vocational school, high school, and vocational college	22.00 (18.00, 27.00)
College degree, undergraduate degree or above	20.00 (16.25, 24.50)
Living
To live alone	22.00 (19.00, 27.00)	0.314	0.754
Not living alone	24.00 (18.00, 28.00)
Per capita household income, yuan
< 2842.5	24.00 (20.25, 28.00)	0.960	0.337
≥ 2842.5	24.00 (18.00, 28.00)
Smoking situation
Never smoking situation	22.00 (17.75, 26.25)	5.699	0.058
Swear off smoking	25.00 (19.00, 28.50)
Smoking situation	21.00 (18.00, 27.50)
Engage in intellectual activities every day
Correct	20.50 (16.00, 26.25)	3.821	< 0.001
Deny	25.00 (19.75, 29.00)
Frequency of physical exercise
0 time/week	25.50 (21.00, 30.00)	30.767	< 0.001
Approximately 1 time/week	22.00 (17.00, 26.00)
≥ 3 times/week	20.00 (16.00, 25.00)
Sleep duration per night
≤ 6 hours	26.00 (22.00, 30.00)	5.667	< 0.001
> 6 hours	21.00 (16.00, 26.00)
Disease duration, years
< 5	22.00 (17.00, 26.00)	15.703	< 0.001
5-10	25.00 (19.00, 29.00)
> 10	25.00 (21.00, 30.00)
Fall history in the past year
No	23.50 (18.00, 28.00)	2.349	0.019
Yes	26.50 (22.50, 30.50)
Polypharmacy
No	24.00 (19.00, 28.00)	1.189	0.235
Yes	22.00 (18.00, 28.00)
Coexistence of multiple illnesses
No	21.00 (16.00, 26.50)	3.024	0.002
Yes	24.00 (19.00, 28.00)
Random blood glucose
Normal	23.00 (18.00, 28.00)	0.932	0.628
Above normal	24.00 (20.00, 28.00)
Below normal	24.00 (21.00, 27.50)
Pulmonary function classification, grade
I	19.00 (13.75, 24.00)	59.504	< 0.001
II	21.00 (16.00, 26.00)
III	25.00 (21.00, 29.75)
IV	27.50 (22.25, 31.00)
Dyspnea classification, level
0	19.00 (12.00, 24.25)	69.582	< 0.001
1	19.00 (14.00, 24.00)
2	21.00 (18.00, 26.00)
3	26.00 (22.00, 29.00)
4	29.00 (22.00, 33.00)
Hypoxemia
No	21.00 (17.00, 26.00)	6.696	< 0.001
Yes	26.00 (22.00, 30.00)
Persist in using inhaled medication
No	25.00 (20.00, 28.00)	3.987	< 0.001
Yes	20.00 (16.00, 27.00)
Long term oxygen therapy status
No	22.00 (18.00, 27.00)	5.18	< 0.001
Yes	28.00 (22.00, 31.00)

Table 6 Assignments for the variables included in the generalized linear model

Factor	Variable	Assignment
Degree of education	X1	1 = “Elementary school and below”, 2 = “Junior high school and vocational school, high school and vocational college”, 3 = “College, undergraduate and above”
Engage in intellectual activities every day	X2	1 = Yes, 2 = No
Frequency of physical exercise	X3	1 = “0 time/week”, 2 = “Approximately 1 time/week”, 3 = “≥ 3 times/week”
Sleep duration per night	X4	1 = “≤ 6 hours”, 2 = “> 6 hours”
Course of disease	X5	1 = “< 5 years”, 2 = “5-10 years”, 3 = “> 10 years”
Fall history in the past year	X6	0 = None, 1 = Yes
Coexistence of multiple illnesses	X7	0 = None, 1 = Yes
Pulmonary function classification	X8	1 = “Level I”, 2 = “Level II”, 3 = “Level III”, 4 = “Level IV”
Dyspnea classification	X9	0 = “Level 0”, 1 = “Level 1”, 2 = “Level 2”, 3 = “Level 3”, 4 = “Level 4”
Hypoxemia	X10	0 = None, 1 = Yes
Persist in using inhaled medication	X11	0 = None, 1 = Yes
Long-term oxygen therapy	X12	0 = None, 1 = Yes
The number of acute attacks in the past year	X13	Continuous variable, no assignment required
Total score of self-management	X14	Continuous variable, no assignment required
Cognitive decline	X15	0 = Did not occur, 1 = Occurred
Total score of quality of life	Y	Continuous variable, no assignment required

Table 7 Multivariate analysis of total quality of life scores in elderly chronic obstructive pulmonary disease patients

Variable	Regression coefficient	SE	95% confidence interval of regression coefficient	χ2-tests	P value
Degree of education
Elementary school and below	Reference
Junior high school and vocational school, high school, and vocational college	-0.478	0.658	-1.767-0.811	0.528	0.467
College degree, undergraduate degree or above	-2.222	1.814	-5.777-1.333	1.501	0.221
Engage in intellectual activities every day
Yes	Reference
No	0.791	0.717	-0.613-2.195	1.219	0.270
Frequency of physical exercise
0 time/week	Reference
Approximately 1 time/week	-1.295	0.798	-2.859-0.270	2.632	0.105
≥ 3 times/week	-1.522	0.932	-3.348-0.305	2.666	0.102
Sleep duration per night
≤ 6 hours	Reference
> 6 hours	-0.990	0.734	-2.429-0.450	1.817	0.178
Course of disease
< 5 years	Reference
5-10 years	0.973	0.766	-0.529-2.475	1.612	0.204
> 10 years	1.665	0.813	0.072-3.259	4.196	0.041
Fall history in the past year
No	Reference
Yes	0.096	1.367	-2.582-2.774	0.005	0.944
Coexistence of multiple illnesses
No	Reference
Yes	-0.731	0.741	-2.183-0.721	0.973	0.324
Pulmonary function classification, grade
I	Reference
II	0.218	1.086	-1.909-2.346	0.041	0.841
III	1.333	1.185	-0.989-3.654	1.266	0.261
IV	0.575	1.611	-2.583-3.733	0.127	0.721
Dyspnea classification, level
0	Reference
1	-0.292	1.445	-3.123-2.540	0.041	0.840
2	1.353	1.548	-1.681-4.387	0.764	0.382
3	2.133	1.683	-1.166-5.432	1.606	0.205
4	3.575	1.908	-0.164-7.315	3.512	0.061
Hypoxemia
No	Reference
Yes	1.924	1.343	-0.709-4.557	2.051	0.152
Persist in using inhaled medication
No	Reference
Yes	1.073	0.976	-0.839-2.985	1.211	0.271
Long term oxygen therapy status
No	Reference
Yes	1.406	0.866	-0.291-3.102	2.637	0.104
The number of acute attacks in the past year	0.319	0.300	-0.269-0.907	1.132	0.287
Self-management rating	-0.058	0.016	-0.089-(-0.026)	12.836	< 0.001
Cognitive decline
No occurrence	Reference
Occur	-1.613	1.379	-4.315-1.089	1.369	0.242

Restricted cubic spline model adjusts for education level, daily intellectual activity, frequency of physical exercise, duration of sleep per night, disease course, history of falls in the past year, comorbidity of multiple diseases, pulmonary function grading, dyspnea grading, hypoxemia, adherence to inhaled medication, long-term oxygen therapy, number of acute attacks in the past year, and cognitive impairment.