| Subjects n | Visit 1 | Visit 2 | Visit 3 | Visit 4 | p-value# | |
| All subjects | 346 | 54 (15.6) | 275 (79.5) | 10 (2.9) | 7 (2.0) | |
| On medication¶ | 164 | 23 (14.0) | 124 (75.6) | 10 (6.1) | 7 (4.3) | <0.001 |
| Not on medication¶ | 182 | 31 (17.0) | 151 (83.3) | 0 (0) | 0 (0) |
Data are presented as n (%), unless otherwise stated. #: comparison between groups; ¶: regular asthma-controlling medications.