Real-world feasibility of adapted European Respiratory Society asthma diagnosis guidelines for school-aged children.

Background: Clinical practice guidelines for asthma diagnosis are rarely evaluated in real-life practice. Within the Swiss Paediatric Airway Cohort (SPAC), we initiated the SPAC-asthma project to develop a standardised diagnostic approach for school-aged asthma, based on the algorithm recommended by the European Respiratory Society (ERS) guideline. Here, we report the development and feasibility of this approach after implementation across multiple paediatric pulmonology clinics. Method: We used a modified Delphi process with paediatric pulmonologists from participating clinics to tailor the ERS algorithm for feasible implementation in children aged 5-17 years with suspected asthma. Key adaptations included selection of initial tests, criteria for further testing, test cut-offs, the role of medication trials, and follow-up procedures. At 1 year after implementation, we evaluated adherence to the adapted approach at four clinics and explored the reasons for any deviations. Results: The final SPAC-asthma approach included spirometry, fractional exhaled nitric oxide and allergy testing as initial tests, followed by either bronchodilator reversibility testing, bronchial challenge test or medication trial. Among the 236 children included after 1 year (median age 9 years), overall adherence to the approach was 77% (182 of 236, 95% CI 72-83%). Deviations were due to practice-related ( Conclusion: The diagnostic approach adapted from the ERS guidelines was feasible in most cases, but the observed deviations highlighted the need for flexibility when applying guidelines in real-world settings.