Prevalence of dementia among Indigenous populations of countries with a very high Human Development Index: a systematic review.

Dementia is a health priority for Indigenous peoples. Here, we reviewed studies on the prevalence of dementia or cognitive impairment among Indigenous populations from countries with a very high Human Development Index (≥0·8). Quality was assessed using the Joanna Briggs Institute risk-of-bias tool and CONSolIDated critERia for strengthening the reporting of health research involving Indigenous peoples (CONSIDER), with oversight provided by an Indigenous Advisory Board. After screening, 23 studies were included in the Review. Relative to the respective non-Indigenous populations, greater age-standardised prevalence ratios were observed in the Australian Aboriginal and Torres Strait Islander (2·5-5·2), Aotearoa-New Zealand Māori (1·2-2·0), and Singaporean Malay (1·3-1·7) populations, and greater crude prevalence ratios were observed in the Canadian First Nation (1·3), Singaporean Malay (2·3), Malaysian Melanau (1·7-4·0), American Indian and Alaska Native (1·0-3·2), and Chamorro of Guam (1·2-2·0) populations. The prevalence ratios were greater across younger age groups, predominantly comprising those younger than 70 years. 14 studies presented a moderate risk of bias and few studies reported Indigenous involvement. Despite improved management of risk factors, a greater prevalence of dementia persists in Indigenous populations, overall and at younger ages than in non-Indigenous populations. Future epidemiological work involving Indigenous populations should uphold and prioritise Indigenous perspectives.