Device adherence and user experience with daily home-based FeNO monitoring (Vivatmo me) in asthma patients: the FeNO@home observational study

Fractional exhaled nitric oxide (FeNO) is an important biomarker of asthma. Daily FeNO monitoring can provide longitudinal data better reflecting the variable nature of asthmatic inflammation versus single-point data. We studied adherence to daily home-based FeNO monitoring, and user experience with the Vivatmo me device and app in asthma patients in a multicentre, 12-week observational study. Adherence to daily FeNO was measured by percentage days covered (PDC) and proportion of adherent patients over time. Patients’ and physicians’ expectations were recorded by questionnaires at study entry, item-specific and global expectation fulfillment and net promoter categories scores at study end. Device usability was measured by User Experience Questionnaire (UEQ+) scores. FeNO values did not trigger direct management decisions. We enrolled n=85 asthma patients (n=23 GINA Step 1; n=37 Step 2-3; n=25 Step 4-5). Adherence to daily FeNO was high with a median PDC of 93.4% (Q1-Q3: 75-97.6%) and 68.2% of subjects covering >80% of measurements. PDC was highest (p=0.04) in asthma patients aged >60 years (median 99%; Q1-Q3: 87-100%) versus 40-60 years (92%; Q1-Q3: 75-98%), and 18-40 years (93%; Q1-Q3: 60-99). Item-specific expectation fulfillment was highest for “to have more safety and predictability in dealing with my asthma” (42% of patients) and “to conclude whether the therapy is suitable for the patient” (76% of physicians), and was related to asthma control. Overall, 49% of patients’, and 87% of physicians’ global expectations towards home monitoring were “fulfilled” or “absolutely fulfilled”. Usability impression was excellent (median UEQ+ score 2.05; Q1-Q3: 1.15-2.65), and handling scores were positively correlated with adherence and promoter categories. Daily FeNO measurements with a home-based device (Vivatmo me) are feasible and well accepted. Adherence over 12 weeks, global expectation fulfillment, and device usability were highly promising, underlining the potential of home-based FeNO to support asthma management. German Clinical Trial Register (DRKS) DRKS00029118, registered JUL 1st, 2022. Parts of the results of the study have been presented in abstract form at the European Respiratory Society (ERS) Annual Congress on SEP 8th, 2025 in Vienna, Austria.