National data sets on prevalence and incidence are important for understanding population trends and allocating healthcare resources. We aimed to provide a current snapshot of national prevalence and annual incidence rate of type one diabetes (T1D) in children aged 0–14 in New Zealand and identify differences associated with geography and ethnicity.
All paediatric diabetes centres across New Zealand were invited to record anonymised demographic and diabetes data on children under their services for the year 1st Oct 2020 to 30th Sept 2021 with a diagnosis of T1D. The national prevalence and incidence, stratified by age, ethnicity, and region was calculated using estimated resident population counts from the 2018 census. The effect of ethnicity on prevalence and incidence was assessed using Poisson regression.
There were 1209 children aged 0-14 with T1DM on October 2021. National prevalence was 128/100,000 (95% CI 121 to 135). Compared to Māori or Pacific Peoples, European have twice the prevalence. There was no effect by gender; and as expected, prevalence increased with age. Collectively children of Māori and Pacific ethnicity made up over 25% of the cohort. The one-year incidence of T1D was 22/100,000 (95% CI 19 to 25). Compared to children of Māori ethnicity, European children were 2.5 times more likely to be diagnosed with T1D in that year (adjusted PRR=2.5, 95% CI 1.55 to 4.02). Regional differences in prevalence and incidence were noted and are shown in figure 1.
In this capture of incidence and prevalence in New Zealand, we demonstrate that T1D affects an ethnically diverse population, and important regional differences exist which may impact workforce planning.