Baseline characteristics | Cross-sectional analysis (N = 2599) Number (%) | Longitudinal analysis (N = 1329) Number (%) | Lost to follow-up (N = 1267) Number (%) |
---|---|---|---|
Age group | |||
18–29 | 415 (16.0) | 134 (10.1) | 281 (22.2) |
30–39 | 553 (21.3) | 263 (19.8) | 290 (22.9) |
40–49 | 664 (25.6) | 369 (27.8) | 295 (23.3) |
50–59 | 523 (20.1) | 341 (25.7) | 181 (14.3) |
60–70 | 444 (17.1) | 222 (16.7) | 220 (17.4) |
Sex | |||
Men | 1299 (50.0) | 659 (49.6) | 639 (50.4) |
Women | 1300 (50.0) | 670 (50.4) | 628 (49.6) |
Carstairs deprivation quintiles | |||
1st (least deprived) | 636 (24.5) | 292 (22.0) | 282 (22.3) |
2nd | 457 (17.6) | 255 (19.2) | 202 (15.9) |
3rd | 523 (20.1) | 307 (23.1) | 241 (19.0) |
4th | 482 (18.6) | 220 (16.6) | 264 (20.8) |
5th (most deprived) | 501 (19.3) | 255 (19.2) | 278 (21.9) |
Smoking status | |||
Never | 1289 (49.6) | 705 (53.1) | 583 (46.0) |
Ex-smoker | 722 (27.8) | 387 (29.1) | 334 (26.4) |
Current smoker | 588 (22.6) | 237 (17.8) | 350 (27.6) |
Distance to a main road | |||
<50 m | 164 (6.3) | 87 (6.6) | 77 (6.1) |
50 – 100 m | 226 (8.7) | 112 (8.4) | 114 (9.0) |
100 – 150 m | 190 (7.3) | 96 (7.2) | 94 (7.4) |
> 150 m | 2019 (77.7) | 1034 (77.8) | 982 (77.5) |
Modelled quintiles of NO 2 (μg/m 3 ) | |||
<33.92 | 520 (20.0) | 267 (20.1) | 252 (19.9) |
33.92 – 34.23 | 520 (20.0) | 279 (21.0) | 240 (18.9) |
34.23 – 34.73 | 520 (20.0) | 277 (20.8) | 242 (19.1) |
34.73 – 36.79 | 520 (20.0) | 248 (18.7) | 272 (21.5) |
>36.79 | 519 (20.0) | 258 (19.4) | 261 (20.6) |
Outcomes* | |||
Current wheeze | 624 (24.0) | 274 (20.6) | 347 (27.4) |
Diagnosed asthma | 231 (8.9) | 102 (7.7) | 128 (10.1) |
COPD** | 238 (9.2) | 102 (7.7) | 135 (10.7) |
BHR† | 310 (13.0) | 147 (11.7) | 163 (12.9) |
Ever hay fever | 662 (25.5) | 323 (24.3) | 337 (26.6) |
Ever eczema | 714 (27.5) | 365 (27.5) | 348 (27.5) |
Allergen skin sensitisation | 788 (30.3) | 406 (30.6) | 381 (30.1) |
High total IgE‡ | 549 (22.3) | 258 (20.2) | 290 (22.9) |