Normal | Non-obstructive | Undiagnosed COPD | Over-diagnosed COPD | Diagnosed COPD | |
N (%) | 18 361 (86) | 1099 (5) | 809 (4) | 756 (4) | 217 (1) |
FEV1 %predicted | |||||
Mean (SD) | 97.9±13.0 | 68.9±8.9*† | 70.4±15.1*† | 88.3±16.6*† | 61.5±16.6* |
>80% | 17 008 (93) | 78 (7)*†† | 232 (29)*† | 534 (71)*† | 28 (13)* |
50%–80% | 1353 (7) | 992 (90) | 500 (62) | 212 (28) | 142 (65) |
30%–50% | 0 (0) | 29 (3) | 73 (9) | 10 (1) | 38 (18) |
Age | |||||
Mean±SD | 62.0±10.0 | 60.8±9.8*† | 61.9±10.5 | 64.6±10.0*† | 67.0±9.9* |
45–54 | 5111 (28)† | 365 (33)*† | 243 (30)† | 140 (18)*† | 25 (11)* |
55–64 | 6310 (34) | 245 (33) | 257 (32) | 245 (32) | 65 (30) |
65–74 | 4233 (23) | 243 (22) | 172 (21) | 215 (28) | 64 (29) |
75+ | 2707 (14) | 131 (12) | 137 (17) | 156 (20) | 63 (29) |
Males | 8660 (47) | 656 (60)*† | 373 (45) | 283 (37)* | 97 (45) |
Cigarette smoking | |||||
Mean±SD | 17.6±16.9 | 27.2±24.3*† | 27.3±22.2*† | 29.3±22.6*† | 42.7±25.7* |
Current | 1183 (6) | 135 (12)*† | 162 (20)*† | 133 (18)*† | 79 (36)* |
Former | 6139 (34) | 583 (53) | 442 (55) | 495 (66) | 126 (58) |
Never | 10 936 (60) | 376 (35) | 203 (25) | 124 (16) | 12 (6) |
Level of education/schooling | |||||
<Secondary | 767 (4) | 74 (7)* | 47 (5)*† | 70 (9)* | 24 (11)* |
Secondary | 1657 (9) | 104 (10) | 78 (9) | 79 (10) | 23 (10) |
>Secondary | 15 913 (87) | 917 (83) | 917 (84) | 606 (70) | 170 (77) |
Yearly income | |||||
<20 k | 678 (4) | 77 (8)*† | 44 (5)*† | 77 (10)* | 27 (13)* |
20–50 | 3402 (20) | 220 (31) | 208 (27) | 220 (31) | 67 (32) |
50–100 | 6144 (36) | 237 (34) | 252 (33) | 237 (33) | 77 (37) |
>100 | 7042 (40) | 172 (27) | 248 (33) | 172 (24) | 36 (17) |
BMI | |||||
Mean±SD | 27.8±8.8 | 31.2±7.0*† | 26.3±4.9*† | 29.7±6.7*† | 27.8±5.6 |
<20 | 444 (2) | 19 (2)*† | 46 (6)*† | 23 (3)*† | 8 (4) |
20–25 | 5345 (29) | 185 (17) | 304 (38) | 152 (20) | 73 (34) |
25–30 | 7579 (41) | 344 (31) | 304 (38) | 267 (35) | 73 (34) |
>30 | 4979 (27) | 551 (50) | 155 (19) | 313 (42) | 63 (29) |
Bronchodilator use, n (%) | |||||
No inhaler | 17 906 (98) | 1036 (94)*† | 700 (87)*† | 614 (81)*† | 115 (53)* |
Short acting | 92 (0.5) | 7 (0.5) | 21 (3) | 20 (3) | 7 (3) |
Long acting | 361 (2) | 55 (5) | 88 (11) | 122 (16) | 95 (44) |
Data are presented as frequency (% of total column) or as mean±SD. The mean±SD for cigarette smoking were calculated for smokers only.
**P<0.05 compared with normal category.
†P<0.05 compared with diagnosed COPD using univariate analysis (analysis of variance or Mann-Whitney tests).
BMI, body mass index; COPD, chronic obstructive pulmonary disease; FEV1, forced expiratory volume in the first second.