Epidemiology of Childhood Asthma in the UK.

Purpose: Global prevalence of pediatric asthma and associated morbidity and mortality has continuously increased. Asthma is the most common chronic illness in children in the UK; however, recent epidemiology data are lacking. This analysis describes the overall prevalence and burden of illness of asthma in children. Methods: This was a retrospective, longitudinal, database analysis using the Clinical Practice Research Datalink database. Primary care records of 19,330 patients (6-11 years) between January 1 and December 31, 2017, were analyzed. Asthma prevalence was assessed by severity (as described by Global Initiative for Asthma 2017 guidelines), and symptoms, comorbidities, and treatments were compared between asthma patients and matched non-asthmatic controls. Results are presented descriptively; logistic regression analyses were performed for asthma symptoms. Results: The estimated prevalence of pediatric asthma was 6.5% (95% CI: 6.4-6.5) in the UK (mild: 74.2%; moderate: 15.0%; severe: 10.8%). All patients with moderate or severe asthma and 72.5% of patients with mild asthma were prescribed drug therapy. Most patients with moderate or severe asthma were prescribed a short-acting β2-agonist (94.9% and 96.0%, respectively), compared with 69.2% of mild asthma patients. Daytime symptoms were reported by 78.1% in those with severe asthma; 34.9% reported night-time symptoms and 30.8% reported an impact on usual activities. Asthma patients had a higher baseline prevalence of comorbidities compared with non-asthmatic controls, notably atopic dermatitis (47.8% in severe asthma versus 20.8% in controls) and allergic rhinitis (13.3% in severe asthma versus 2.0% in controls). Conclusion: This analysis confirmed that asthma remains a common morbidity among children in the UK. Increasing asthma severity was associated with worsening symptoms, and asthma patients had significantly more comorbidities compared with non-asthmatic controls.