Table 1 Characteristics of the study population and unadjusted means of HRQL
Total sample | COPD grade 1 | COPD grade 2 | COPD grade 3 | COPD grade 4 | p-value | ||
|---|---|---|---|---|---|---|---|
n (%) | 2,291 | 206 (9.0) | 962 (42.0) | 874 (38.1) | 249 (10.9) | ||
Age | Mean age (SD) | 65.1 (8.4) | 66.2 (8.7) | 65.7 (8.5) | 65.0 (8.2) | 62.1 (8.0) | <0.0001 |
% < 55 years (n) | 11.4 (262) | 9.7 (20) | 10.3 (99) | 11.2 (98) | 18.1 (45) | <0.0001 | |
% 55 – 64 years (n) | 33.6 (769) | 27.2 (56) | 31.7 (305) | 34.3 (300) | 43.4 (108) | ||
% 65 – 74 years (n) | 43.2 (989) | 48.1 (99) | 44.5 (428) | 43.8 (383) | 31.7 (79) | ||
% > 74 years (n) | 11.8 (271) | 15.1 (31) | 13.5 (130) | 10.6 (93) | 6.8 (17) | ||
Sex | % male (n) | 60.9 (1,396) | 60.2 (124) | 60.2 (579) | 61.0 (533) | 64.3 (160) | 0.70 |
School education | % basic education (n) | 55.4 (1,270) | 48.5 (100) | 52.2 (502) | 60.0 (524) | 57.8 (144) | 0.0002 |
% secondary education (n) | 27.1 (620) | 25.2 (52) | 28.6 (275) | 25.2 (220) | 29.3 (73) | ||
% higher education (n) | 17.5 (401) | 26.2 (54) | 19.2 (185) | 14.9 (130) | 12.9 (32) | ||
Smoking status | % smokers (n) | 24.7 (565) | 30.1 (62) | 28.8 (277) | 21.7 (190) | 14.5 (36) | <0.0001 |
% former smokers (n) | 68.8 (1,576) | 62.6 (129) | 63.6 (612) | 72.7 (635) | 80.3 (200) | ||
% never smokers (n) | 6.6 (150) | 7.3 (15) | 7.6 (73) | 5.6 (49) | 5.2 (13) | ||
BMI | Mean BMI (SD) a | 26.7 (5.2) | 26.6 (4.6) | 27.4 (5.1) | 26.4 (5.4) | 24.4 (5.0) | <0.0001 |
% normal weight (n) | 37.1 (848) | 36.4 (75) | 32.6 (313) | 38.5 (336) | 49.8(124) | <0.0001 | |
% overweight (n) | 37.1 (848) | 42.2 (87) | 38.9 (374) | 36.2 (316) | 28.5 (71) | ||
% obese (n) | 22.4 (512) | 19.9 (41) | 27.0 (259) | 20.9 (182) | 12.1 (30) | ||
% underweight (n) | 3.5 (81) | 1.5 (3) | 1.6 (15) | 4.5 (39) | 9.6 (24) | ||
Mean FEV1 % pred. | 52.5 (18.6) | 88.6 (8.1) | 62.7 (8.3) | 40.7 (5.6) | 24.8 (3.9) | <0.0001 | |
Mean BODE index (SD) b | 2.5 (2.0) | 0.4 (0.7) | 1.3 (1.2) | 3.6 (1.5) | 5.3 (1.6) | <0.0001 | |
Comorbidities | Mean number (SD) | 3.7 (2.6) | 4.1 (2.7) | 3.9 (2.6) | 3.7 (2.6) | 3.1 (2.3) | <0.0001 |
% low number of comorbidities (n) | 52.6 (1,206) | 48.5 (100) | 50.6 (487) | 52.9 (462) | 63.1 (157) | 0.003 | |
% high number of comorbidities (n) | 47.4 (1,085) | 51.5 (106) | 49.4 (475) | 47.1 (412) | 37.0 (92) | ||
HRQL | EQ-5D utility (SD) c | 0.82 (0.20) | 0.85 (0.18) | 0.84 (0.19) | 0.81 (0.21) | 0.74 (0.24) | <0.0001 |
EQ-5D VAS (SD) d | 56.5 (19.6) | 66.9 (17.4) | 61.0 (18.8) | 52.2 (18.8) | 45.5 (17.8) | <0.0001 | |
CAT score (SD) e | 18.2 (7.4) | 14.2 (6.8) | 16.9 (7.1) | 19.4 (7.2) | 22.1 (6.8) | <0.0001 | |
SGRQ score (SD) f | 43.6 (20.0) | 28.0 (15.8) | 38.7 (19.1) | 48.6 (17.9) | 58.4 (18.0) | <0.0001 | |