Defining lung function in asthma remission: Results of an international Delphi study

BACKGROUND: A consensual criterion regarding lung function (LF) assessment that could be included in the definition of asthma remission on treatment (tAR) is currently lacking. RESEARCH QUESTION: This work aimed to identify a criterion concerning LF evaluation corresponding to this concept. METHODS: A survey was conducted using the Delphi method. The scientific board established 16 candidate statements to be included in the questionnaire. A 5-point Likert scale was used to measure agreement for each statement. The predefined conditions for statement selection were a median score ≥ 4 and >60% of responses indicating agreement. The survey included four rounds: three including the board members and one - 177 participants through the Interasma Scientific Network platform. RESULTS: Following the first two rounds, six statements reaching consensus were included in the large survey. They incorporated various definitions used for 'normal' and 'stable' LF together with elimination of airway hyperresponsiveness and variability during bronchodilator testing. Three statements gained consensus during the third round. The final selected criterion associates 'stable LF' over time with a 'negative reversibility test' or 'negative challenge test'. CONCLUSION: AR after prospective validation.