Establishing Age-Specific Normative Data for the NIH Toolbox among Urban-Dwelling American Indian and Alaska Native Elders in the URBANE Study

This study presents group norms for fluid, crystallized, and total cognition scores on the NIH Toolbox among urban-dwelling American Indian and Alaska Native (AI/AN) Elders. From 2021 to 2024, the URBan Native Elders study recruited 1007 (n = 994) Elders to elucidate risk and protective factors for Alzheimer’s Disease and related dementias (ADRD). Volunteers self-identified as AI/AN, were aged 55 years and older, and lived in or commuted to urban areas in the United States defined by Rural Urban Commuter Area codes. Participants underwent extensive medical interview and neurocognitive assessment. When comparing total participants assigned female at birth to total participants assigned male at birth, the former had higher overall uncorrected standard scores across fluid (mean 88.0, SD 11.1 vs mean 83.6, SD 13.0), crystallized (mean 105, SD 10.3 vs mean 104, SD 10.0), and total (mean 95.4, SD 10.3 vs mean 92.8, SD 11.9) domains than the latter. Potential influential factors for differences in composite scores include a high burden of traumatic brain injury (34.9%) and 66.2% attending at least one year of college. Findings from this data will inform clinical and public health decisions while forming the foundation of future longitudinal research on ADRD in AI/AN people.