Global Initiative for Asthma 2005 classification of asthma severity: clinical features before treatment
| Asthma Severity | Clinical features before treatment | ||
| Symptoms | Nocturnal symptoms | FEV1 or PEF | |
| Step 4: severe persistent | ContinuousLimited physical activity | Frequent | ≤60% pred>30% variability |
| Step 3: moderate persistent | DailyAttacks affect activity | >1 time per week | 60–80% pred>30% variability |
| Step 2: mild persistent | >1 time per week but <1 time per day | >2 times per month | ≥80% pred20–30% variability |
| Step 1: intermittent | <1 time per weekAsymptomatic and normal PEF between attacks | ≤2 times per month | ≥80% pred<20% variability |
The presence of one feature of severity is sufficient to place a patient in that category. FEV1: forced expiratory volume in one second; % pred: % predicted; PEF: peak expiratory flow. Reproduced from [4] with permission from the publisher.