According to a study by Ingrid Looijmans-van den Akker, Karen van Luijn and Theo Verheij, overdiagnosis is common in children with asthma in primary care. The researchers retrospectively examined 652 children (>6 years) from four Dutch primary care health centers. Spirometry confirmed asthma diagnosis in only 16% of the children. 23% of the children experienced asthmatic signs and symptoms. In 54% of the children the diagnosis could not be confirmed by spirometry or sign and symptoms. These children were overdiagnosed with asthma according to the researchers. Reasons for an asthma diagnosis in these children were dyspnoea (32%), cough (26%) and wheezing (10%). Results if this study are relevant because the overdiagnosing leads to unnecessary treatment and possible impaired quality of life.