Introduction: Asthma is the commonest chronic disease in children and asthma attacks result in significant morbidity. We assessed the association between demographic and clinical risk factors and asthma-related hospital admissions in children and adolescents and estimated the proportion of hospital admissions potentially attributable to modifiable risk factors.

Methods: Cohort study of English primary care records from 1st January 2017 to 31st December 2019 in the Clinical Practice Research Datalink Aurum database and linked Hospital Episode Statistics Admitted Patient Care data using descriptive statistics, negative binomial regression, and population attributable risk fractions (PAF).

Results: Data from 90,989 children (5-11 years) and 114,927 adolescents (12-17 years) were analysed over a mean follow-up of 2. 7 years. The hospitalisation rate per thousand person years was 20 (95%CI 19.5-20.6) for children and 10 (95%CI 9.7-10.4) for adolescents. In children, risk factors included belonging to an ethnic minority group, increasing socioeconomic deprivation, allergies (PAF 11.4%, 95% CI 6.8 to 15.8), and atopic eczema (6.8%, 3.6 to 9.9). In adolescents, risk factors also included being female, former smoking (PAF 6.8%, 0.9 to 12.3), and allergic rhinitis. ?6 salbutamol inhaler prescriptions in the previous year were associated with a 5-fold increase in risk.

Conclusion: Our study, highlights important risk factors for severe asthma attacks requiring hospitalisations in children and adolescents. Identification and treatment of modifiable risk factors have significant potential to reduce severe asthma attacks.