Introduction: Asthma is a common chronic disease across the life course and exacerbations result in significant morbidity. We assessed the association between demographic and clinical risk factors and asthma-related ICU admissions.

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 and negative binomial regression.

Results: A total of 1,385,326 patients were included in the study comprising 90,989 children, 114,927 adolescents, and 1,179,410 adults. The incidence rate of asthma-related ICU admissions (per 1,000 person years) was 0.54 (95% CI 0.45-0.64) in children, 0.29 (95%CI 0.23- 0.35) in adolescents and 0.15 (95% CI 0.14-0.16) in adults. Patients from black ethnic minority groups were at increased risk across all age groups compared to white patients (IRR 4, 95% CI 2.3-7 in children, IRR 3.5, 95% CI 1.6 to 7.6 in adolescents, IRR 2.69, 95% CI 1.7 to 4.1 in adults). Adolescent and adult females, patients from the most socioeconomically deprived quintile, and adults with depression were also at increased risk. Prescription of ?6 salbutamol prescriptions and multiple asthma medications across all age groups were associated with increased ICU admissions.

Conclusion: Black ethnicity, high socioeconomic deprivation, depression, and high medication burden are important risk factors for asthma-related ICU admissions and should be considered when risk stratifying patients.