Table 1.
Classification of asthma-according to severity of clinical features
| Intermittent |
| Symptoms < once a week |
| Brief exacerbations |
| Nocturnal symptoms not > twice a month |
| • FEV1 or PEF ≥ 80% predicted |
| • PEF or FEV1 variability < 20% |
| Mild persistent |
| Symptoms > once a week but < once a day |
| Exacerbations may affect activity and sleep |
| Nocturnal symptoms > twice a month |
| • FEV1 or PEF ≥ 80% predicted |
| • PEF or FEV1 variability < 20-30% |
| Moderate persistent |
| Symptoms daily |
| Exacerbations may affect activity and sleep |
| Nocturnal symptoms > once a week |
| Daily use inhaled short-acting β2-agonist |
| • FEV1 or PEF 60-80% predicted |
| • PEF or FEV1 variability > 30% |
| Severe persistent |
| Symptoms daily |
| Frequent exacerbations |
| Frequent nocturnal asthma symptoms |
| Limitation of physical activities |
| • FEV1 or PEF ≤ 60% predicted |
| • PEF or FEV1 variability > 30% |