Figure 4

Diagnostic criteria overlap. Venn diagram showing overlap between the four diagnostic asthma criteria asthma diagnosed by a physician, ever had asthma, four or more wheezing episodes during the past 12 months, and being on inhalation steroid therapy in ordinary day-care centre children 1–6 years old. Percentages refer to number of children with criterion or criteria combination in relation to total ordinary day-care centre study population.