Table 2

Nitric oxide (NO) and clinical measurements in children with difficult asthma before and after prednisolone

Measurement Visit 1 Visit 2 p value Mean difference before and after treatment
NO (ppb)11.2 (7.9 to 15.9)7.5 (5.3 to 10.1)<0.011.5 (1.2 to 2.0)
FEV1 (% predicted)72 (63 to 81)78 (70 to 86)NS
Post bronchodilator FEV1 (% predicted)82 (74 to 90)84 (77 to 90)NS
PC20 (mg/ml) (n = 7)0.92 (0.19 to 4.41)2.12 (0.49 to 9.06)<0.050.44 (0.21 to 0.91)
Symptom free days (%) (n = 21)0 (0–0.25)0 (0–56)NS
Bronchodilator use (puffs per day) (n= 21)3 (2–3.8)2.6 (0.8–3.1)NS
Mean morning PEF (% predicted) (n = 19)76 (65 to 87)84 (76 to 93)<0.058.1 (1.7 to 14.4)
PEF coefficient of variation (n = 19)10.8 (6.9–19.8)9.4 (4.4–17.4)NS
  • FEV1 = forced expiratory volume in one second; PC20 = concentration of methacholine provoking a fall in FEV1 of 20% or more; PEF = peak expiratory flow.

  • Pre-and post-bronchodilator FEV1 and morning PEF data are expressed as means with 95% confidence intervals. NO and PC20 data are expressed as geometric means with 95% confidence intervals. Symptom free days, bronchodilator use, and PEF coefficient of variation are expressed as medians with interquartile range. For statistically significant findings an estimate of effect is given as the mean (95% confidence interval) difference before and after treatment.