Asthma is the most common childhood non-infectious lung disease in the United Kingdom, affecting \~8% of children. Asthma symptoms include wheezing (a high-pitched whistling sound created by turbulent airflow through narrowed airways) associated with difficulty in breathing and shortness of breath, often with a dry cough. Asthma is characterised by episodic (wheeze attacks) and variable symptoms which fluctuate day-to-day. An asthma, or wheeze attack, is a sudden worsening of symptoms, associated with airway obstruction that requires treatment to open up the airways.
Preschool children (aged 1-5 years) account for the majority (75%) of hospital admissions for acute attacks of wheezing in the UK. Up to half of all preschool children will suffer at least one episode of wheezing by their 6th birthday, and 7.8% of preschool children came to primary care with acute wheezing in 2017 in the UK. Frequent severe wheeze attacks in preschool age are the strongest risk factor for diminished lung function at physiological peak in early adulthood and are associated with chronic obstructive pulmonary disease (COPD) in the sixth decade of life, as well as early all-cause mortality and cardiovascular and metabolic comorbidities. It is therefore vital to prevent wheeze attacks in preschool children.
Preschool children experience a 5-times higher rate of hospitalisation for acute wheeze attacks compared to school-aged children. This suggests overt symptoms present late, and not soon enough, for early intervention to prevent attacks in preschool children. The number of unscheduled healthcare presentations of acute wheeze attacks has not decreased for the last 2 decades for preschool children, while it has been declining for school-aged children and adults, resulting in a high socioeconomic burden in the UK and worldwide.
Failure to prevent wheeze attacks in preschool children is in part due to the absence of age-specific remote and objective monitoring technology for disease severity. Currently, in this age group, symptoms are diagnosed and monitored by subjective assessments of airway obstruction (narrowing). Evidence that the symptoms improve following treatment with inhaled bronchodilators is used as an indirect indication of the presence of reversible airway obstruction, which is a cardinal feature of asthma. In school-aged children and adults, airway obstruction is monitored objectively with lung function tests such as spirometry. Spirometry can be performed remotely at home to aid telemedicine monitoring in asthma. However, spirometry requires a forced expiratory manoeuvre and cooperation from the patient. It can thus only be reliably performed in children over 5 years old. As a result, diagnosis and monitoring of wheezing/asthma in preschool children depends on parental reports, clinical examination and subjective assessment of symptoms, but no objective measures of airway obstruction.
For this study, time-course lung function data will be obtained using a novel home-based wearable device designed for preschool children that detects airway obstruction whilst the child is asleep (Ventica®). Also, eliciting objective confirmation of wheeze will be obtained by the use of the WheezeScan® device, which detects presence/absence of wheeze when placed on the child's chest. This information will contribute to developing an app that combines symptoms, medication use, and lung function to allow wheeze detection and provide a personalised plan for parents to seek healthcare advice.
STUDY HYPOTHESES
1. A mobile-based system integrating data on remote lung function, symptoms and medication use can be used to predict the development of an acute attack of wheeze in children aged 1-5 years.
2. The dynamic change in lung function reflects underlying airway pathology in severe wheezing
STUDY OBJECTIVES
1. To develop a mobile app system that collects data on lung function, symptoms and medication use, and returns personalised prediction for preschool wheezers, empowering parents to self-manage their child's wheeze/asthma.
2. To quantify airway inflammation and remodelling in endobronchial biopsies and broncho-alveolar lavage from a subgroup of preschool children with severe wheezing and relate pathology to the pattern of airway obstruction detected using the Ventica® system.
3. To develop prediction models that integrate patient-specific abnormal patterns in time-course lung function data, symptoms recorded using with and without WheezeScan®, and rescue medication use, providing early warning of deterioration.
