Table 1.

Diagnostic criteria for asthma

1 A history of at least one asthma-like symptom: prolonged cough, wheezing, attacks of or exercise-induced dyspnoea, or nocturnal cough orwheezing and

2 Demonstration of reversibility in airways obstruction in lung function investigations [8]:

Significant improvement in response to short-acting bronchodilating medication in a bronchodilator test. The criteria for significant changes were:

FEV1: ≥15%

FVC: ≥15%

PEF: ≥23%

and/or

≥20% daily variation and/or ≥15% improvement2 in response to short-acting bronchodilating medication during at least 2 days in a 2-weekdiurnal PEF follow-up

and/or

Significant improvement in spirometric lung function (for percentage criteria see above) and/or ≥20% improvement in the average PEF level in response to a 2-week oral steroid treatment

¹FEV₁ = forced expiratory volume in one second, FVC = forced vital capacity, PEF = peak expiratory flow.

²Calculated according to the standard practice of the Tampere University Hospital: maximum daily variation = (highest PEF value during the day – lowest PEF value during the day)/highest PEF value during the day; bronchodilator response = (highest PEF value after bronchodilating medication – highest PEF value before medication)/highest PEF value before medication.