Table 5 Distribution of patients according to severity score at 2 years and bronchial responsiveness to methacholine (PD20 methacholine) at 10 years of age
PD20 <1 μmol (%)PD20 1-<8 μmol (%)PD20 ⩾8 μmol (%)
Severity score 0 (n = 211)18 (8.5)66 (31.3)127 (60.2)
Severity score >5 (n = 90)20 (22.2)30 (33.3)40 (44.5)
  • Significantly more patients with severity score >5 had severe bronchial responsiveness (PD20 methacholine <1 μmol) (χ2 = 15.3304, p = 0.0041).