Overdiagnosis of asthma in children in primary care: a retrospective analysis.

BACKGROUND Asthma is one of the most common chronic diseases in childhood. According to guidelines, a diagnosis of asthma should be confirmed using lung function testing in children aged >6 years. Previous studies indicate that asthma in children is probably overdiagnosed. However, the extent has not previously been assessed. AIM To assess the extent and characteristics of confirmed and unconfirmed diagnoses of asthma in children who were diagnosed by their GP as having asthma or who were treated as having asthma. DESIGN AND SETTING Retrospective analysis in four academic primary healthcare centres in Utrecht, the Netherlands. METHOD Routine care registration data of children aged 6-18 years who received a diagnosis of asthma or were treated as having asthma were analysed. RESULTS In only 16.1% (n = 105) of the children diagnosed with asthma was the diagnosis confirmed with spirometry, whereas in 23.2% (n = 151) the signs and symptoms did give rise to suspected asthma but the children should have undergone further lung function tests. In more one-half (53.5%, n = 349) of the children the signs and symptoms made asthma unlikely and thus they were most likely overdiagnosed. The remaining 7.2% (n = 47) were probably correctly classified as not having asthma. The main reasons for classifying asthma without children undergoing further lung function tests were dyspnoea (31.9%, n = 174), cough (26.0%, n = 142), and wheezing (10.4%, n = 57). CONCLUSION Overdiagnosis of childhood asthma is common in primary care, leading to unnecessary treatment, disease burden, and impact on quality of life. However, only in a small percentage of children is a diagnosis of asthma confirmed by lung function tests.