Sensitivity analysis using a stricter definition for asthma# (N=14 939)
| Regular use of cod liver oil and multivitamin supplements in the previous year | Subjects n | Cases n (%) | Crude OR (95% CI) | Adjusted OR (95% CI) | ||
| Model I¶ | Model II+ | Model III§ | ||||
| Reference groupƒ | 12 175 | 238 (2.0) | 1.00 | 1.00 | 1.00 | 1.00 |
| Cod liver oil only | 1008 | 29 (2.9) | 1.49 (1.00–2.20) | 1.72 (1.16–2.56) | 1.71 (1.15–2.54) | 1.63 (1.09–2.44) |
| Multivitamin supplements only | 861 | 26 (3.0) | 1.56 (1.04–2.36) | 1.50 (0.99–2.28) | 1.49 (0.98–2.27) | 1.43 (0.94–2.18) |
| Use of both | 895 | 30 (3.4) | 1.74 (1.18–2.56) | 1.90 (1.28–2.83) | 1.90 (1.28–2.83) | 1.81 (1.21–2.70) |
The association of the use of cod liver oil and multivitamin supplements with cumulative incidence of asthma over the 11-year follow-up period of the Nord-Trøndelag Health Study from 1995–1997 to 2006–2008. #: stricter definition for asthma was participants who were free from wheeze and asthma at baseline who reported asthma at follow-up in combination with use of asthma medication; participants who were free from wheeze and asthma both at baseline and at follow-up served as reference group. ¶: adjusted for age, sex, smoking (current, former, never and unknown), light physical activity, education, social benefit, economic difficulties, family history of asthma and body mass index. +: adjusted for alcohol consumption in addition to the covariates in model I. §: adjusted for Hospital Anxiety and Depression Scale (HADS) scores for anxiety and depression, and chronic disease at baseline, in addition to the covariates in model I (n=14 827 due to missing HADS scores). ƒ: nonusers or those with daily intake of cod liver oil or multivitamin supplements for <3 months.