STEPs-Classification

STEPS - Classification of Asthma Severity

Clinical features before treatment.

Classification	Symptoms	Nighttime Symptoms	Lung Function
STEP 1 Mild Intermittent	Symptoms less than twice a week Asymptomatic and normal PEF between exacerbations Exacerbations brief (from a few hours to a few days); intensity may vary	Less than twice a month	FEV₁or PEF greater than 80% of predicted PEF variability less than 20%
STEP 2 Mild Persistent	Symptoms less than twice a week but lasting longer than a day Exacerbations may affect activity	More than twice a month	FEV₁ or PEF less than 80% of predicted PEF variability 20% to 30%
STEP 3 Moderate Persistent	Daily symptoms Daily use of inhaled short-acting beta₂-antagonist Exacerbations affect activity Exacerbations more often than twice a week; may last for days	More than once a week	FEV₁ or PEF 60% to 80% of predicted PEF variability greater than 30%
STEP 4 Severe Persistent	Continual symptoms Limited physical activity Frequent exacerbations	Frequent	FEV₁ or PEF less than 60% of predicted PEF variability greater than 30%

National Asthma Education and Prevention Program Expert Panel Report 2: Guidelines for the Diagnosis and Management of Asthma

The presence of one of the features of severity is sufficient to place a patient in that category. An individual should be assigned to the most severe grade in which any features occurs. The characteristics noted in this figure are general and may overlap because asthma is highly variable. Furthermore, an individual's classification may change over time.

Patients at any level of severity can have mild, moderate, or severe exacerbations. Some patients with intermittent asthma experience severe and life-threatening exacerbations separated by long periods of normal lung function and no symptoms.