Perceptions, Attitudes, and Real-World Use of FENO in Allergy and Asthma Practice: Results of a National Survey from Türkiye

OBJECTIVE: To evaluate real-life use, perceived clinical value, and barriers to the implementation of fractional exhaled nitric oxide (FeNO) among allergy-immunology specialists in Türkiye. METHODS: This nationwide online survey, developed by the Asthma Working Group of the Turkish National Society of Allergy and Clinical Immunology, included 35 multiple-choice questions administered to pediatric and adult allergy-immunology specialists and fellows after the 30th National Congress. RESULTS: Of the 200 respondents, 75% (n = 150) were female, 54% (n = 108) were early-career physicians, and the majority (n = 125, 62.5%) worked in a university or training and research hospital. Asthma was identified as the primary indication for FeNO measurement by 95% (n = 190), of participants. FeNO was most frequently perceived as useful for phenotyping patients before biologic therapy initiation (n = 150,75.0%), monitoring treatment response (n = 141,70.5%), assessing asthma severity (n = 105, 52.5%), and supporting diagnosis (n = 85, 42.5%). In asthma management, FeNO was considered valuable for guiding decisions before biologic therapy (n = 173, 86.5%), assessing treatment adherence (n = 147, 73.5%), estimating exacerbation risk (n = 134, 67.0%), and adjusting inhaled corticosteroid doses (n = 119, 59.5%). Nearly all participants (n = 195, 97.5%) agreed that FeNO should be used as a complementary tool. However, only 7.0% (n = 14) reported routine FeNO use in daily practice. Limited device access, high cost, lack of reimbursement, and insufficient training were identified as major barriers. Knowledge gaps were prominent, with 61% reporting little or no practical knowledge of FeNO. CONCLUSION: This first national survey demonstrates a marked gap between clinicians' recognition of FeNO's clinical value and its limited real-world use in Türkiye, largely due to cost, access, and educational barriers.