Asthma overdiagnosed in the Netherlands

This article¹ has unfortunately been widely publicised in a sensational and, in my opinion, destructive manner in the UK.² Although only five of the 110 patients diagnosed with spirometry, in this study, were found to be incorrectly diagnosed, the accuracy of the diagnosis in the remaining 500+ patients in this study has not been established. A retrospective analysis of the medical records is only as accurate as the quality of the records and the documented processes used to determine a diagnosis. As the authors state, spirometry is not widely available and, furthermore, nor is quality-assured spirometry. In primary care, serial peak expiratory flow measurements can and, in my opinion, should be used to diagnose reversible airflow obstruction in primary care. It is very difficult to accept the results of this study without detailed corroboration of the assertions that so many of these children don’t have asthma. It is well recognised that many people with asthma don’t adhere to medical treatment and the assumption by the authors, that failure to collect medication indicates unlikely asthma diagnosis, may be false.

Furthermore, as the disease is defined by its variability it doesn’t follow that someone who doesn’t have exacerbations doesn’t have asthma; they may simply be tolerating the symptoms. A sensible next step, rather than accusing GPs of overdiagnosing asthma, would be a prospective primary care study utilising serial peak expiratory flow to establish accuracy of diagnosis, in all patients currently diagnosed with asthma, as well as those suspected as such in the future. Let’s not go back to the 1980s where asthma was underdiagnosed and undertreated.³