Asthma exacerbations in New Zealand 2010-2019: A national population-based study.

INTRODUCTION: Asthma is one of the most common long-term conditions in the world, with New Zealand (NZ) having one of the highest rates of asthma symptoms. Despite the significant burden of asthma in NZ, there is a lack of data on asthma exacerbation rates in NZ and how these have varied over time. This study is a national population-based study of asthma exacerbation rates in NZ between 2010 and 2019, and explores how these rates vary amongst different demographic groups. METHODS: A retrospective population-based observational cohort study covering the ten years 2010-2019 to determine asthma prevalence, and asthma exacerbation and hospitalisation rates, using de-identified data from five national healthcare datasets. Exacerbations were defined based on hospital discharge diagnoses or oral corticosteroid dispensing. RESULTS: Total number of patients with asthma was 447,797 in 2010 to 512,627 in 2019, equating to approximately 10% of the population. Of these 19.4% experienced an exacerbation in 2010 (a population rate of 376.2 per 1000 patient-years); this exacerbation rate increased to 25.1% in 2019 (438.3 per 1000 patient-years). Exacerbations rates were consistently higher for females than males, and among Pacific peoples and Maori. In contrast, hospital admissions 25% lower in 2019 than 2010, decreasing from 1.4% to 0.9%, however over 50% of these admissions were in Maori and Pacific peoples. CONCLUSION: Asthma exacerbation rates in NZ have increased over 2010-2019, however hospitalisation rates have decreased. This potentially suggests a move away from secondary to primary care management of exacerbations and provides important information for asthma care planning.