Objective detection of wheeze at home by parents through a digital device: usage patterns and relationship with SABA administration.

Introduction: Wheezing is an important indicator of exacerbated respiratory symptoms in early childhood and must be monitored to regulate pharmacological therapy. However, parents' subjective perception of wheezing in their children is not always precise. We investigated the objective identification of children's wheezing by parents using a digital wheeze detector (WheezeScan^TM, OMRON Healthcare Co. Ltd), its longitudinal usage patterns, and its relationship with SABA administration.

Methods: We conducted a secondary nested analysis of data from the intervention arm of a multi-center randomized controlled trial completed in 2021-2022 in Berlin (Germany), London (United Kingdom), and Istanbul (Turkey). Children aged 4 to 84 months with doctor's diagnosed wheezing (GINA step 1 or 2) were included. Using an electronic diary (Wheeze-Monitor^TM, TPS), parents monitored and recorded for 120 days at home the presence or absence of their child's wheezing, detected both, with WheezeScan^TM ("objective" wheezing), and subjective ("perceived" wheezing). Parents also recorded the child's symptoms, medication intake, and family quality of life. Questionnaires regarding symptom control, quality of life, and parental self-efficacy were answered at baseline and after 90 and 120 days.

Results: Eighty-one/87 families completed the intervention arm of the study. WheezeScan^TM was on average used 0.7 (SD 0.6) times a day, with each patient reporting a positive, negative, or "error" outcome on average in 57%, 39%, and 5% of measurements, respectively. The use of WheezeScan^TM declined slightly during the first 90 days of monitoring and steeply thereafter. Repeated usage of WheezeScan^TM in the same day was more frequent after a "wheeze" (HR 1.5, 95% CI 1.37-1.65, p < 0.001) and an "error" (HR 2.01, 95% CI 1.70-2.38, p < 0.001) result, compared to a "no wheeze" outcome. The average per-patient daily agreement between "objective" and "perceived" wheezing/non-wheezing was 75% at the start of the monitoring period and only weakly persisted as time passed (Spearman's rho=0.09). The frequency of short-acting beta-2-agonists (SABA) administration was lower in days with closely interspaced consecutive device uses during which the patient's status was perceived as "never wheeze" (32/455, 7%) than in those perceived as "persistent wheeze" (53/119, 44%; OR 36.6, 95% CI [14.3, 94.1]).

Conclusion: Daily use of a digital WheezeScan^TM at home allows parents to detect their child's unperceived wheezing and discloses to caregivers the longitudinal patterns of a child's wheezing disorder. Digital monitoring of wheezing also highlights poor adherence to guidelines in SABA administration for wheezing children, with under-treatment being much more frequent than over-treatment. This pioneering study opens new perspectives for further investigation of digital wheeze detectors in the early diagnosis and proper self-management of wheezing disorders in childhood.