Baseline
Assessment of allergic rhinitis was performed in 290 (71%) of the 411 children at 7 years, in 353 (86%) children at 12 years and in 368 (90%) children at either 7 and/or 12 years. The latter defined the study population. Accordingly, assessment of aeroallergen sensitization was performed in 296 (72%) of the children at 6 years, in 315 (77%) children at 12 years and in 352 (86%) children at either 6 and/or 12 years. Baseline characteristics including gender, socioeconomics, early life exposures, and allergic predisposition of the included and excluded children are outlined in Table 1 . The excluded children (N=43) had fewer older siblings than the included children (no older siblings: 68% vs. 60%, p=0.04), but did not differ with respect to the remaining baseline characteristics.