Co-Morbidity, Body Mass Index and Quality of Life in COPD Using the Clinical COPD Questionnaire

Figures & data

Table 1.  Patient characteristics in primary and secondary care

Characteristics	Primary care (n = 639)	Secondary care (n = 280)	P-value
Sex
Male	267 (41.8%)	125 (44.6%)
Female	372 (58.2%)	155 (55.4%)	0.42
Age
≤50	46 (7.2%)	16 (5.7%)	0.41
51–60	134 (21.0%)	51 (18.2%)	0.34
61–70	315 (49.3%)	150 (53.6%)	0.23
>70	144 (22.5%)	63 (22.5%)	0.99
Educational level
Lower	428 (67.0%)	187 (66.8%)
Higher	211 (33.0%)	93 (33.2%)	0.95
Smoking
Current	215 (33.6%)	47 (16.8%)	<0.0001
Sometimes	39 (6.1%)	19 (6.8%)	0.70
Ex	345 (54.0%)	198 (70.7%)	<0.0001
Never	40 (6.3%)	16 (5.7%)	0.75
Comorbidity
Heart disease	123 (19.2%)	85 (30.4%)	<0.0001
Diabetes mellitus	66 (10.3%)	25 (8.9%)	0.51
Depression	82 (12.8%)	27 (9.6%)	0.17
Body mass index
<20	57 (8.9%)	44 (15.7%)	0.002
≥20, <25	230 (36.0%)	92 (32.9%)	0.36
≥25, <30	238 (37.2%)	86 (30.7%)	0.06
≥30	114 (17.8%)	58 (20.7%)	0.30
CCQ^*
CCQ total	2.01 ± 1,29	2.71 ± 1.35	<0.0001
CCQ symptoms	2.21 ± 1.19	2.72 ± 1.29	<0.0001
CCQ mental state	2.01 ± 1.80	2.83 ± 1.89	<0.0001
CCQ functional state	1.82 ± 1.48	2.65 ± 1.63	<0.0001
Lung function^**
Stage 1	69 (25.3%)	25 (12.4%)	<0.0001
Stage 2	124 (45.4%)	82 (40.6%)	0.29
Stage 3	68 (24.9%)	62 (30.7%)	0.16
Stage 4	12 (4.4%)	33 (16.3%)	<0.0001

Data presented as n (%) or mean ± SD.

^*CCQ = Clinical COPD questionnaire

^**For subgroup with available spirometry data (n = 475).

Table 2.  Association between patient characteristics and CCQ

Characteristics	Mean CCQ ± SD	Adjusted regression coefficient^* (95% CI)	P-value
Level of care
Primary care	2.01±1.29	Ref^**
Secondary care	2.71±1.35	0.60 (0.41 to 0.78)	<0.0001
Sex
Male	2.29±1.33	Ref
Female	2.18±1.36	−0.12 (−0.30 to 0.06)	0.18
Age
31–50	1.98±1.36	−0.03 (−0.39 to 0.32)	0.86
51–60	2.06±1.33	−0.15 (−0.37 to 0.07)
61–70	2.25±1.38	Ref	0.19
71–80	2.38±1.26	0.12 (−0.10 to 0.34)	0.28
Educational level
Lower	2.33±1.36	Ref
Higher	2.03±1.29	−0.24 (−0.42 to 0.05)	0.01
Smoking
Current	2.06±1.30	Ref
Sometimes	2.32±1.56	0.06 (−0.31 to 0.43)	0.75
Ex	2.33±1.35	0.13 (−0.07 to 0.33)	0.20
Never	1.91±1.28	−0.25 (−0.63 to 0.14)	0.21
Heart disease
Absent	2.13±1.36	Ref
Present	2.55±1.26	0.26 (0.06 to 0.47)	0.01
Diabetes
Absent	2.23±1.35	Ref
Present	2.19±1.34	−0.04 (−0.32 to 0.24)	0.79
Depression
Absent	2.19±1.35	Ref
Present	2.53±1.26	0.50 (0.23 to 0.76)	<0.0001
Body mass index
<20	2.79±1.48	0.58 (0.29 to 0.87)	<0.0001
≥20, <25	2.14±1.31	Ref
≥25, <30	2.03±1.29	−0.13 (−0.33 to 0.07)	0.20
≥30	2.43±1.32	0.21 (−0.04 to 0.45)	0.09

^*Regression coefficients representing mean differences in CCQ, adjusted for all variables shown.

^**Reference.

Figure 1.  COPD co-morbidity and CCQ score. A higher CCQ score indicates lower quality of life.

Figure 2.  Body Mass Index and CCQ score. A higher CCQ score indicates lower quality of life.

Figure 3.  Lung function and CCQ score. A higher CCQ score indicates lower quality of life.

Table 3.  Association between patient characteristics and separate CCQ domains

Characteristics	CCQ; symptoms Adjusted regression coefficient^* (95%CI)	CCQ; mental state Adjusted regression coefficient (95%CI)	CCQ functional state Adjusted regression coefficient (95%CI)
Level of care
Primary care	Ref	Ref	Ref
Secondary care	0.48 (0.30 to 0.60)	0.74 (0.48 to 1.00)	0.65 (0.44 to 0.86)
Sex
Male	Ref	Ref	Ref
Female	−0.30 (−0.48 to −0.13)	0.15 (−0.10 to 0.40)	−0.08 (−0.28 to 0.13)
Level of education
Lower	Ref	Ref	Ref
Higher	−0.16 (−0.34 to 0.02)	−0.39 (−0.65 to −0.13)	−0.23 (−0.44 to −0.02)
Heart disease
Absent	Ref	Ref	Ref
Present	0.19 (−0.02 to 0.39)	0.15 (−0.15 to 0.44)	0.40 (0.16 to 0.63)
Diabetes
Absent	Ref	Ref	Ref
Present	−0.13 (−0.40 to 0.15)	−0.02 (−0.41 to 0.38)	0.04 (−0.29 to 0.36)
Depression
Absent	Ref	Ref	Ref
Present	0.35 (0.10 to 0.61)	0.69 (0.32 to 1.05)	0.54 (0.24 to 0.84)
BMI
BMI <20	0.54 (0.26 to 0.82)	0.48 (0.07 to 0.88)	0.68 (0.34 to 1.01)
20< BMI <25	Ref	Ref	Ref
25< BMI <30	−0.02 (−0.22 to 0.17)	−0.28 (−0.55 to 0.01)	−0.17 (−0.40 to 0.06)
BMI >30	0.14 (−0.10 to 0.37)	0.29 (−0.05 to 0.64)	0.24 (−0.04 to 0.52)

^*Regression coefficients representing mean differences in CCQ, adjusted for all variables from Table 2.

Table 4.  Association between patient characteristics and CCQ, stratified for sex

Variable	Mean CCQ ± SD	Men Adjusted regression coefficient^* (95%CI)	Mean CCQ ± SD	Women Adjusted regression Coefficient (95%CI)
Level of care
Primary care	2.07 ± 1.34	Ref	1.97 ± 1.26	Ref
Secondary care	2.75 ± 1.21	0.52 (0.24 to 0.80)	2.68 ± 1.46	0.65 (0.40 to 0.90)
Level of education
Lower	2.41 ± 1.34	Ref	2.27 ± 1.38	Ref
Higher	2.07 ± 1.30	−0.22 (−0.49 to 0.06)	1.99 ± 1.29	−0.24 (−0.49 to 0.00)
Heart disease
Absent	2.17 ± 1.36	Ref	2.10 ± 1.35	Ref
Present	2.54 ± 1.23	0.24 (−0.05 to 0.53)	2.57 ± 1.32	0.34 (0.04 to 0.65)
Diabetes
Absent	2.29 ± 1.34	Ref	2.19 ± 1.35	Ref
Present	2.27 ± 1.28	0.10 (−0.32 to 0.51)	2.11 ± 1.40	−0.12 (−0.51 to 0.27)
Depression
Absent	2.26 ± 1.33	Ref	2.12 ± 1.37	Ref
Present	2.64 ± 1.30	0.34 (−0.18 to 0.86)	2.49 ± 1.25	0.52 (0.21 to 0.83)
BMI
BMI <20	3.07 ± 1.42	0.61 (0.10 to 1.12)	2.67 ± 1.50	0.64 (0.28 to 0.10)
20≤ BMI <25	2.40 ± 1.39	Ref	1.98 ± 1.24	Ref
25≤ BMI <30	1.98 ± 1.23	−0.41 (−0.71 to −0.11)	2.08 ± 1,36	0.12 (−0.15 to 0.39)
BMI ≥30	2.50 ± 1.25	0.01 (−0.38 to 0.39)	2.38 ± 1.38	0.30 (−0.01 to 0.62)

^*Regression coefficients representing mean differences in CCQ in, adjusted for all variables from Table 2.