Prevalence of ever-had asthma and current asthma by each subgroup for each cohort and for the pooled dataset
| Ever-had asthma | Current asthma | |||||||
| HUNT3 | Lifelines | UK Biobank | Pooled | HUNT3 | Lifelines | UK Biobank | Pooled | |
| Subjects | ||||||||
| Total | 50 805 | 93 277 | 502 649 | 646 731 | 50 805 | 93 277 | 502 649 | 646 731 |
| With asthma information | 50 783 | 93 056 | 500 505 | 644 344 | 50 783 | 93 056 | 493 157 | 636 996 |
| Prevalence | 5953 (11.7) | 7930 (8.5) | 57 911 (11.6) | 71 794 (11.1) | 3900 (7.7) | 3954 (4.3) | 19 509 (4.0) | 27 363 (4.3) |
| Sex | ||||||||
| Male | 2575 (11.2) | 3178 (8.3) | 24 199 (10.6) | 29 952 (10.4) | 1604 (7.0) | 1387 (3.6) | 7707 (3.4) | 10 698 (3.8) |
| Female | 3378 (12.2) | 4752 (8.7) | 33 712 (12.4) | 41 842 (11.8) | 2296 (8.3) | 2567 (4.7) | 11 802 (4.4) | 16 665 (4.7) |
| p-value# | 0.00 | 0.03 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Age years | ||||||||
| <50 | 2563 (12.0) | 5933 (9.5) | 15 571 (13.3) | 24 127 (12.0) | 1568 (7.3) | 2819 (4.5) | 5150 (4.5) | 9537 (4.8) |
| ≥50 | 3390 (11.5) | 1937 (6.5) | 42 340 (11.1) | 47 667 (10.8) | 2332 (8.0) | 1135 (3.8) | 14 359 (3.8) | 17 826 (4.1) |
| p-value# | 0.11 | 0.00 | 0.00 | 0.00 | 0.01 | 0.00 | 0.00 | 0.00 |
| BMI kg·m−2 | ||||||||
| <25 | 1658 (10.1) | 3246 (7.7) | 16 961 (10.3) | 21 865 (9.8) | 1027 (6.2) | 1497 (3.6) | 5705 (3.5) | 8229 (3.7) |
| 25–30 | 2506 (11.2) | 3039 (8.3) | 23 404 (11.1) | 28 949 (10.7) | 1600 (7.2) | 1523 (4.2) | 7745 (3.7) | 10 868 (4.1) |
| ≥30 | 1734 (15.0) | 1644 (11.4) | 17 207 (14.1) | 20 585 (13.9) | 1234 (10.7) | 934 (6.5) | 5977 (5.0) | 8145 (5.6) |
| p-value# | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Smoking | ||||||||
| Never-smoker | 2156 (10.2) | 3599 (9.2) | 31 550 (11.6) | 37 305 (11.2) | 1291 (6.1) | 1879 (4.8) | 10 544 (3.9) | 13 714 (4.2) |
| Ex-smoker | 2098 (13.0) | 2136 (7.7) | 20 406 (11.8) | 24 640 (11.4) | 1452 (9.0) | 1165 (4.2) | 6832 (4.0) | 9449 (4.4) |
| Current smoker | 1541 (12.6) | 1606 (8.1) | 5697 (10.8) | 8844 (10.4) | 1052 (8.6) | 629 (3.2) | 2031 (3.9) | 3712 (4.4) |
| p-value# | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.33 | 0.00 |
| Education | ||||||||
| Lower | 1447 (12.9) | 248 (11.0) | 9830 (11.6) | 11 525 (11.7) | 1039 (9.3) | 145 (6.5) | 3681 (4.4) | 4865 (5.0) |
| Medium | 1962 (11.7) | 5225 (8.5) | 11 977 (10.9) | 19 164 (10.2) | 1247 (7.4) | 2643 (4.3) | 4109 (3.8) | 7999 (4.3) |
| Higher | 809 (9.9) | 2265 (8.4) | 35 027 (11.8) | 38 101 (11.5) | 472 (5.8) | 1075 (4.0) | 11 343 (3.9) | 12 890 (3.9) |
| p-value# | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
Data are presented as n or n (%), unless otherwise stated. BMI: body mass index. #: Chi-squared test, significance level at 0.05.