Adjusted and unadjusted multiple logistic regression model for the association of self-reported nickel allergy and pierced ears with incident wheezing for males and females; imputed data, excluding those with wheezing at baseline
| Male (n=759) | Female (n=1009) | |||||
| Incident wheezing# | cOR (95%CI) | aOR¶ (95%CI) | Incident wheezing# | cOR (95%CI) | aOR¶ (95%CI) | |
| Nickel allergy | ||||||
| Never | 41 (6.0%) out of 688 | 1 | 1 | 43 (6.3%) out of 681 | 1 | 1 |
| Ever | 9 (16.4%) out of 55 | 3.05 (1.39–6.67) | 2.90 (1.29–6.52) | 32 (10.6%) out of 309 | 1.78 (1.10–2.87) | 1.57 (0.96–2.57) |
| Pierced ears | ||||||
| No | 34 (5.5%) out of 617 | 1 | 1 | 5 (5.2%) out of 97 | 1 | 1 |
| Yes | 16 (11.6%) out of 138 | 2.22 (1.19–4.15) | 2.26 (1.10–4.62) | 71 (7.8%) out of 910 | 1.56 (0.61–3.96) | 1.27 (0.49–3.27) |
cOR: crude odds ratio; aOR: adjusted odds ratio. #: obtained from nonimputed data; ¶: adjusted for potential confounders (smoking status, parental socioeconomic status (SES), participant's SES, study centre and parental history of asthma).