Symptoms/Day	Symptoms/Night	PEF or FEV1	PEF variability
STEP 1 Intermittent	< 1 time a week Asymptomatic and normal PEF between attacks	</= 2 times a month	>/= 80%	< 20%
STEP 2 Mild Persistent	> 1 time a week but < 1 time a day Attacks may affect activity	> 2 times a month	>/= 80%	20-30%
STEP 3 Moderate Persistent	Daily Attacks affect activity	> 1 time a week	60%-80%	> 30%
STEP 4 Severe Persistent	Continuous Limited physical activity	Frequent	</= 60%	> 30%

 

PEF, Peak Expiratory Flow; FEV₁, Forced Expiratory Volume in the first second.

• The presence of one of the features of severity is sufficient to place a patient in that category.

• Patients at any level of severity-even intermittent asthma-can have severe attacks.

References:

Masoli M, Fabian D, Holt S, Beasley R; Global Initiative for Asthma (GINA) Program. The global burden of asthma: executive summary of the GINA Dissemination Committee report. Allergy. 2004 May;59(5):469-78. [Medline]
Bousquet J. Global initiative for asthma (GINA) and its objectives. Clin Exp Allergy. 2000 Jun;30 Suppl 1:2-5. [Medline]