Managing asthma in the outpatient clinic: Is the diagnosis of asthma confirmed objectively according to guidelines?

BACKGROUND: GINA guidelines recommend that a diagnosis of asthma is confirmed by an objective measurement of lung function or the presence of airway hyperresponsiveness. However, currently no diagnostic flowchart exists on asthma, and objective tests are used inconsistently. AIM: To examine the use of diagnostic tests in newly referred patients with possible asthma in a specialized outpatient clinic. METHODS: The MAPOut I study is a retrospective observational study of all patients consecutively referred to a tertiary hospital specialist clinic over a 12-month period, on suspicion of asthma (n=221). Data on lung function, peak flow, reversibility to beta2-agonist and airway hyperresponsiveness (AHR) was collected. RESULTS: Of 221 patients referred to the outpatient clinic with possible asthma, 128 (58.4%) were diagnosed with asthma. At least one objective test was performed in 103 (80.5) of the 128 subjects diagnosed with asthma (reversibility (57.8%), bronchial provocation (53.1%), PEF monitoring (5.0%). Among these 128 subjects, 80 had at least one positive test confirming presence of disease, corresponding to 63% of all subjects diagnosed with asthma. CONCLUSION: Among patients diagnosed with asthma in a tertiary specialist clinic, the diagnosis of asthma was confirmed objectively in 63%. In a significant proportion of patients, treatment decisions were based solely on the presence of symptoms.