Factors associated with good self-rated health and quality of life in subjects with self-reported COPD

Figures & data

Table 1 Characteristics of the subjects (n = 1475)

	Combined 2004 + 2008 n = 1 475	2004 n = 664	2008 n = 811	P value
Age (years)	69.1 (9.7)	68.9 (9.8)	69.3 (9.6)	0.25
Female sex (%)	46.0	43.8	47.8	0.06
BMI (kg/m^2)	26.1 (5.0)	25.9 (4.7)	26.3 (5.3)	0.10
Economic problems (%)	15.0	16.1	14.1	0.296
Alcohol use the past 12 months (%)				0.678
2–4 times a month or more	48.7	48.1	49.2
Once a month or less/never	51.3	51.9	50.8
Educational level (%)				0.001
Compulsory school	57.3	67.8	54.7
Grammar school	16.1	13.2	18.5
University	12.3	11.1	13.3
Other	10.9	7.8	13.4
Social support (%)				0.422
No	9.1	9.1	9.1
Yes, probably	26.3	27.9	24.9
Yes, certainly	64.6	63.0	66.0
Smoking status (%)				0.179
Never smokers	12.3	13.6	11.2
Ex-smokers	54.6	52.2	56.6
Current smokers	33.1	34.2	32.2
Physical activity (%)				0.828
Sedentary	39.3	40.5	38.3
Moderate exercise (low activity)	43.7	43.4	44.0
Moderate regular exercise	11.4	10.8	11.9
Regular exercise and training	5.6	5.3	5.8
Employment status (%)				0.423
Employed or studying	17.1	15.6	18.3
Sick leave or sickness pension	13.6	13.7	13.6
Retired	69.3	70.7	68.1
Comorbidity factors (%)
Cardiovascular disease	33.8	35.5	32.5	0.11
Hypertension	45.3	44.9	45.5	0.41
Asthma	42.8	45.9	40.3	0.02
Depression	26.2	27.3	25.3	0.19
Chronic fatigue syndrome	21.8	23.3	20.6	0.11

Notes: Economic problems, difficulty in managing current expenditure during the past 12 months. Data are presented as mean (standard deviation) or percentage. Differences were calculated for 2004–2008 using t-test, for age and BMI. Differences between ordinal variables were tested using a chi-square test.

Abbreviation: BMI, body mass index.

Figure 1 Selection of the population surveyed.

Abbreviation: COPD, chronic obstructive pulmonary disease.

Table 2 General health and quality of life (n = 1 475)

	Combined 2004 + 2008 n = 1 475	2004 n = 664	2008 n = 811	P value
General health status (%)				0.038
Very good	1.7	1.5	1.9
Good	22.0	19.5	24.1
Neither good nor poor	43.9	44.8	43.3
Poor	28.1	28.5	27.8
Very poor	4.2	5.7	3.0
GHQ12; not impaired psychological well-being (%)	76.7	74.5	78.5	0.04
EQ-5D index value [0–1]	0.63 (0.27)	0.61 (0.28)	0.65 (0.26)	0.002
EQ-5D no problems (%)
Mobility	48.6	46.9	50.1	0.11
Self-care	89.8	88.5	90.8	0.08
Usual activities	61.3	58.6	63.5	0.03
Pain/discomfort	13.6	12.4	14.5	0.12
Anxiety/depression	49.4	47.3	51.1	0.07

Notes: Differences for 2004–2008 were tested using t test for EQ-5D. Differences between proportions were tested using the asymptotic normal test for binomial data. The difference in general health was tested with a chi-square test.

Abbreviations: GHQ12, General Health Questionnaire 12-item version, impaired well-being defined as present when the total score was 3 or higher; EQ-5D, EuroQol five-dimension questionnaire, index value (standard deviation): [1 = full health, 0 = death].

Figure 2 Relationship between self-rated general health (x-axis) and physical activity in leisure time.

Table 3 Associations between background factors and measures of general health and quality of life

	General health OR (95% CI)	GHQ12 OR (95% CI)	EQ-5D Effect on median (95% CI)
Age (standardized)		FP U-shaped, minimum at 68 years	−0.008 (−0.018, 0.001)
Bad vs very bad	1.147 (0.850, 1.547)
Bad/neither good nor bad vs bad	1.095 (0.945, 1.269)
Good vs neither good nor bad	0.828 (0.711, 0.965)
Very good vs good	0.454 (0.308, 0.669)
Sex	1.158 (0.928, 1.445)	1.054 (0.787, 1.411)	−0.010 (−0.026, 0.007)
BMI (standardized)	1.103 (0.988, 1.232)	0.909 (0.787, 1.050)	0.002 (−0.006, 0.011)
Economic problems
Yes	1 (ref)	1 (ref)	0 (ref)
No		0.372 (0.254, 0.545)	0.057 (0.032, 0.081)
Bad vs very bad	1.923 (0.950, 3.894)
Bad/neither good nor bad vs bad	1.082 (0.740, 1.582)
Good vs neither good nor bad	2.113 (1.311, 3.406)
Very good vs good	1.184 (0.375, 3.731)
Alcohol use the past 12 months
4 times a week or more	1 (ref)	1 (ref)	0 (ref)
2–3 times a week	1.421 (0.911, 2.217)	1.201 (0.653, 2.211)	0.012 (−0.021, 0.045)
2–4 times a month	1.452 (0.964, 2.185)	1.139 (0.645, 2.012)	0.004 (−0.027, 0.035)
Once a month or less	0.995 (0.656, 1.508)	1.426 (0.809, 2.514)	0.001 (−0.031, 0.032)
Never		1.629 (0.918, 2.891)	−0.032 (−0.063, 0.000)
Bad vs very bad	0.372 (0.186, 0.743)
Bad/neither good nor bad vs bad	1.021 (0.651, 1.602)
Good vs neither good nor bad	0.958 (0.589, 1.558)
Very good vs good	0.476 (0.104, 2.172)
Educational level
Compulsory school	1 (ref)	1 (ref)	0 (ref)
Grammar school	0.978 (0.722, 1.326)	1.236 (0.826, 1.848)	−0.010 (−0.033, 0.014)
University	1.318 (0.932, 1.863)	1.445 (0.933, 2.238)	0.014 (−0.011, 0.040)
Other	0.808 (0.570, 1.146)	1.488 (0.964, 2.295)	−0.018 (−0.044, 0.008)
Social support
No	1 (ref)	1 (ref)	0 (ref)
Yes, probably	1.303 (0.853, 1.991)	0.632 (0.392, 1.018)	0.039 (0.008, 0.070)
Yes, undoubtedly	2.060 (1.384, 3.066)	0.316 (0.201, 0.495)	0.052 (0.023, 0.082)
Smoking status
Yes, I smoke daily	1 (ref)	1 (ref)	0 (ref)
Yes, I smoke sometimes		1.002 (0.530, 1.894)	0.014 (−0.024, 0.052)
Bad vs very bad	0.431 (0.168, 1.102)
Bad/neither good nor bad vs bad	1.886 (0.990, 3.595)
Good vs neither good nor bad	1.149 (0.606, 2.180)
Very good vs good	1.068 (0.139, 8.198)
No, I have stopped smoking	1.081 (0.833, 1.404)	0.792 (0.568, 1.103)	−0.004 (−0.023, 0.016)
No, I have never smoked	1.744 (1.184, 2.568)	0.528 (0.314, 0.888)	0.014 (−0.015, 0.042)
Physical activity
Sedentary	1 (ref)	1 (ref)	0 (ref)
Moderate exercise (low activity)	2.390 (1.869, 3.056)	0.549 (0.403, 0.748)	0.044 (0.026, 0.062)
Moderate regular exercise	3.547 (2.434, 5.169)	0.538 (0.325, 0.890)	0.077 (0.050, 0.104)
Regular exercise and training	7.772 (4.662, 12.968)	0.511 (0.263, 0.993)	0.087 (0.051, 0.123)

Notes: Economic problems, difficulty in managing current expenditure during the past 12 months. Social support was assessed according to the question: “Do you have any persons in your vicinity who can give you personal support in case of personal problems or life crises?” General health odds >1 resulted in higher odds for better health. GHQ12 odds ratios <1 resulted in lower odds for psychological distress. Those cases where several odds ratios were reported for general health indicated heterogeneous associations between the explanatory variable and outcome. Significant effects are in bold face.

Abbreviations: GHQ12, General Health Questionnaire 12-item version; EQ-5D, EuroQol five-dimension questionnaire index; OR, odds ratio; CI, confidence interval; FP, fractional polynomials; ref, reference value; BMI, body mass index.