Incidence of Young Onset Dementia in Waikato, New Zealand: A Population-Based Study

Background: There is limited epidemiological research on the incidence of young onset dementia (YOD). Estimates of YOD incidence in New Zealand are extrapolated from international studies that do not reflect New Zealand's population and ethnic diversity. Objective: To determine the incidence of YOD in the geographical area served by the Waikato District Health Board Methods: All new inpatient and outpatient in the age range 30-64 years with a documented diagnosis of dementia at Waikato Hospital between 1 January 2014 31 December 2016 were identified. Incidence rates were calculated by 5-year age-band, sex, and ethnicity. Results: 64 incident cases of YOD were included. Incidence rates for all cause YOD were 13.3 (95% CI 10.3-17.0) and 22.7 (95% CI 17.5-29.1) per 100,000 person-years in the age range 30-64 years and 45-64 years respectively. The incidence rate in Maori (20.0, 95%CI 11.4-32.4) was higher compared to non-Maori (12.0, 95%CI 8.9-15.9), but this difference was not statistically significant (p = 0.09). Conclusion: The incidence of YOD in this study is similar to global estimates. Incidence may be higher in Maori compared to non-Maori, highlighting the need for culturally appropriate approaches to dementia prevention, intervention, and care.