Details of the whole cohort, participants where data were available from the Prescribing Information System (PIS) and participants where data were available from questionnaires and clinical assessments at 15 years of age
| Original population | PIS data available at 15 years of age | Questionnaire returned at 15 years of age | |
| Participants | 1924# | 1699# | 750# |
| Male | 50 (968) | 50 (854) | 46 (340) |
| Deprivation quintile¶ | |||
| SIMD 1 | 15 (284) | 16 (266) | 10 (72) |
| SIMD 2 | 9 (167) | 9 (157) | 8 (55) |
| SIMD 3 | 14 (268) | 14 (238) | 15 (105) |
| SIMD 4 | 22 (420) | 23 (380) | 23 (165) |
| SIMD 5 | 39 (734) | 38 (647) | 44 (317) |
| Maternal smoking during pregnancy | 29 (566) | 30 (518/1698) | 19 (135/719) |
| Maternal asthma | 16 (316) | 17 (288/1698) | 15 (110/719) |
| CRL z-score | 0±1.00 (n=1206) | 0.005±0.99 (n=1170) | 0.034±0.93 (n=476) |
| BPD z-score | 0±1.00 (n=1676) | 0.002±0.99 (n=1622) | 0.020±0.98 (n=623) |
| Femur length z-score | 0.00±1.00 (n=1670) | 0.010±1.00 (n=1616) | 0.040±1.02 (n=622) |
| Birthweight kg | 3.41±0.61 (n=1841) | 3.44±0.56 (n=1815) | 3.48±0.56 (n=691) |
| Wheeze in the last 12 months | NA | NA | 15 (115/750) |
| Asthma diagnosed by physician | NA | NA | 20 (147/750) |
| Asthma medications | NA | NA | 13 (96/748) |
| Current eczema | NA | NA | 16 (121/750) |
| Current hay fever | NA | NA | 36 (270/750) |
| Skin prick positive+ | NA | NA | 44 (244/549) |
| Currently exposed to cigarette smoke | NA | NA | 5 (34/686) |
| FEV1 z-score | NA | NA | −0.18±1.05 (n=514) |
| FEF25–75 z-score | NA | NA | 0.12±0.96 (n=515) |
Data are presented as n, % (n) or mean±sd. SIMD: Scottish Index of Multiple Deprivation; CRL: crown–rump length; BPD: biparietal diameter; FEV1: forced expiratory volume in 1 s; FEF25–75: forced expiratory flow at 25–75% of forced vital capacity; NA: not assessed. #: unless otherwise indicated; ¶: 1=most deprived quintile, 5=least deprived quintile [27]; +: defined as a wheal ≥3 mm to house dust mite, cat, timothy grass and egg.