Patient-reported symptoms during the past 14 days by asthma severity grade
| Intermittent | Mild persistent | Moderate persistent | Severe persistent | |
| Subjects n | 174 | 134 | 153 | 39 |
| ≥1 night waking up because of asthma % | 10.9# | 43.3# | 59.5# | 76.9# |
| Nights woken up nights | 0.19±0.66* | 1.26±2.07* | 3.13±4.03* | 7.18±5.8* |
| ≥1 day with daytime symptoms % | 45.4# | 79.1# | 85.6# | 89.7# |
| Days with symptoms days | 1.13±1.87* | 4.33±4.39* | 6.41±5.00* | 9.33±5.31* |
| Symptom-free days days | 12.87±1.87 | 9.67±4.39 | 7.59±5.00 | 4.67±5.31 |
| No symptoms % | 51.7# | 14.9# | 10.5# | 5.1# |
| Limitations in normal daily activities because of asthma symptoms % | ||||
| Limited on rare occasions | 88.9# | 43.1# | 30.2# | 3.1# |
| Slightly limited most or all of the time | 11.1# | 52.9# | 27.1# | 25.0# |
| Moderately limited most or all of the time | 0.0# | 3.9# | 37.5# | 59.4# |
| Severely limited most or all of the time | 0.0# | 0.0# | 5.2# | 12.5# |
| Asthma exacerbations or worsening of symptoms % | ||||
| None | 52.0# | 12.7# | 9.2# | 2.6# |
| Brief (lasting a few hours to a few days) | 46.2# | 67.9# | 37.9# | 12.8# |
| Slight impact on sleep and activities most or all of the time | 1.7# | 15.7# | 26.1# | 18.0# |
| Moderate impact on sleep and activities most or all of the time | 0.0# | 3.7# | 22.2# | 46.2# |
| Major impact on sleep and activities most or all of the time | 0.0# | 0.0# | 4.6# | 20.5# |
Data are presented as mean±sd unless otherwise indicated
*: p<0.05 versus all other severity groups (analysis of variance with post hoc comparisons between severity groups)
#: p<0.05 overall association between severity and the symptom (Chi-squared test for homogeneity)