“…Both studies evaluated the validity of registered asthma diagnosis based on information on asthma-related characteristics reported in medical files such as (episodic) wheezing, dyspnea, cough, family history for atopic diseases, sensitivity for non-specific irritants, allergy test, and reversibility in pulmonary function test [5, 17]. Based on an algorithm of combination of symptoms, Pauwelse classified patients into probable asthma, unlikely asthma, and insufficient data for the diagnose asthma [5, 17]. Looijmans classified patients as confirmed, probable, unlikely, and no asthma [5, 17].…”