Table 1– Demographic data, body mass index (BMI) and respiratory morbidity in the two cohorts
Cohort 1Cohort 2
Subjects n9781819
Year of questionnaire survey19901998
Age years2.99 (2.92–3.06)3.13 (3.08–3.18)
Males50.6 (495) (47.5–53.8)52.7 (958) (50.4–55.0)
BMI z-scores−0.693 (−0.143–0.004)0.104 (0.052–0.156)
Current wheeze11.9 (116) (9.8–13.9)26.3 (478) (24.3–28.3)
Doctor-diagnosed asthma11.0 (108) (9.1–13.0)18.6 (339) (16.8–20.4)
Frequent wheeze#6.1 (60) (4.6–7.6)13.4 (244) (11.8–15.0)
Multiple-trigger wheeze5.1 (50) (3.7–6.5)9.8 (179) (8.5–11.2)
Hospital admission for wheeze3.4 (33) (2.2–4.5)6.4 (117) (5.3–7.6)
  • Data are presented as mean (95% CI) or % (n) (95% CI), unless otherwise stated. #: three or more episodes in the previous 12 months; : wheezing occurring also between episodes of respiratory infections.