NIH/NAEPP classification of asthma severity:
a) Based on: Symptoms, nighttime awakenings, rescue inhaler use, lung function
b) Mild intermittent: Symptoms ≤2 days/week, nighttime awakenings ≤2 times/month
c) Moderate persistent: Daily symptoms, daily rescue inhaler use
d) Severe persistent: Continuous symptoms, frequent exacerbations