Table 4

Perinatal and non-perinatal risk factors for asthma among 16 year old Finnish adolescents combined in a single model4-1 4-2

Risk factorsRisk of asthma
(n = 3285)		Attributable proportion4-3
OR95% CI
Ponderal index in quarters
 Lowest1.0
 2nd0.970.57 to 1.67
 3rd0.940.55 to 1.61
 Highest1.744-4 1.07 to 2.8517%
Maternal smoking
 Never1.0
 Ever1.591.09 to 2.3125%
Parental asthma
 No1.0
 Yes5.253.39 to 8.1223%
Number of older siblings
 0−11.032%
 2+0.610.38 to 0.99

  • ↵4-1 Selection of variables by backward stepwise logistic regression.

  • ↵4-2 Regression results corrected by generalised estimating equations (GEE).

  • ↵4-3 Proportion of cases due to exposure to the risk factor among all those exposed and unexposed.26

  • ↵4-4 Test for trend p<0.01.