Table 1 Characteristics of study children (n = 546).
| Mean (SD) age (years) | 10.2 (3.8) |
| Sex (M/F) | 342/204 |
| Mean (SD) body mass index | 19.0 (4.3) |
| Mean (SD) PEFR (% of mean predicted) | 89.7 (17.2) |
| Mean (SD) FEV1 (% of mean predicted) | 97.0 (15.1) |
| Mean (SD) FVC (% of mean predicted) | 93.9 (13.4) |
| BTS step of asthma treatment* | |
| Step 1 | 79 (14.5%) |
| Step 2 | 303 (55.5%) |
| Step 3 | 92 (16.8%) |
| Step 4 | 72 (13.2%) |
| Number on inhaled salmeterol (steps 3 + 4) | 164 (30.0%) |
| School absences (yes/no) over previous 6 months | 191/546 (35%) |
| Courses of oral steroids (yes/no) over previous 6 months | 109/546 (20%) |
| Hospital admissions (yes/no) over previous 6 months | 63/546 (12%) |
| Overall asthma exacerbations† (yes/no) over previous 6 months | 215/546 (39%) |
FVC, forced vital capacity; FEV1, forced expiratory volume in 1 second; PEFR, peak expiratory flow rate.
*Step 1 = inhaled β2 agonists alone; step 2 = step 1 + inhaled steroids; step 3 = step 2 + inhaled long acting β2 agonists; step 4 = step 3 + montelukast.
†Defined as any one of the following in the previous 6 months: school absences, courses of oral steroids, or hospital admissions.