Normative cognitive test performance and typical error patterns among American Indian older adults: The Strong Heart Study.

OBJECTIVE: The Strong Heart Study, a large cohort of American Indians from three U.S. regions, collected standardized neuropsychological assessments from participants aged 65-95 years at two visits (2010-2019), with prior documentation of lower overall score distributions and higher prevalence of cognitive impairment and dementia. This report aims to define expected score ranges for impaired and unimpaired as well as typical error patterns across this multidomain battery. METHOD: Participants were assessed as cognitive unimpaired (normal) or impaired through case review by a panel of clinicians-experts. Cognitive test score distributions were summarized and regression-normalized by age, sex, education, baseline cognition, bilingual status, and depression. RESULTS: The strongest determinants of variability explained in test scores were age, education, and baseline cognition; depression was also associated with some tests. Error patterns were similar between overall group and intact group. Subitem analyses suggested that some tasks did not contribute to overall scores because most participants either correctly or incorrectly responded to the item. Common item analyses between similar tests suggested that interference may change score interpretability for similar tasks when repeated on different tests. CONCLUSIONS: These data represent the best estimates of expected cognitive test performance for older American Indians and may be useful to clinicians and researchers hoping to contextualize individual performance for patients within this sociodemographic. These results suggest that more research is needed among other Tribal groups, other Indigenous peoples, other socioeconomic contexts, younger ages, and with longitudinal evaluation. (PsycInfo Database Record (c) 2026 APA, all rights reserved).