Prevalence of cognitive impairment in Brazilian indigenous community from Amazonas

Abstract

ABSTRACT. Studies on the prevalence of dementia in the indigenous population are still scarce worldwide. In the few available studies, prevalence evidence varies from low to very high, with early onset of the disease and high mortality rate after the initial diagnosis. Still, little is known about the rate of dementia in indigenous populations from low- and middle-income countries, where the dementia prevalence in the general population is estimated to increase significantly in the next decades. Objective: This study aimed to determine the prevalence of cognitive impairment and associated factors in Brazilian indigenous people of the Mura ethnicity in Amazonas, Brazil. Methods: A total of 217 indigenous individuals aged 50 years and older from Amazonas, Brazil, were submitted to cognitive assessment. Attention, memory, verbal fluency, visuospatial performance, and mood state composed the cognitive impairment diagnosis. Results: The prevalence of cognitive impairment was 43.3% (95%CI 36.6-49.7) and varied according to age [OR=1.03 (95%CI 1.00-1.06)], education [OR=0.74 (95%CI 0.62-0.87)], body mass index [OR=0.91 (95%CI 0.83-0.98)], and income [OR=0.52 (95%CI 0.27-0.99)]. Conclusions: Cognitive impairment had an early onset in an indigenous community, and its prevalence was greater in older individuals with low education and low family income. These findings highlight the importance of implementing public indigenous health policies focusing on health professional training for early cognitive impairment detection.

Culturally adapted cognitive assessment tool for Indigenous communities in Brazil: Content, construct, and criterion validity

“…32 In our study, merging expert and stakeholder feedback yielded a culturally sensitive cognitive assessment tool that is brief, valid, easy to apply, and cost-effective compared to traditional cognitive tests used in Brazilian Indigenous contexts. 15,30 Validating the BRICA marks an essential advancement in the early detection of cognitive disorders in urban Indigenous communities within the Brazilian Amazon.…”

“…32 Besides validity, the BRICA yields other advantages as a dementia screening tool, such as its shorter application time (10-15 minutes), culturally appropriate content, and cost effectiveness. 13,15 These benefits stem from its concise nature, allowing faster implementation than other non-Indigenous Brazilian studies' methodologies. The traditional cognitive tools, though popular in assessing cognitive status in elderly Brazilians, 3 tend to overestimate dementia prevalence when applied exclusively.…”

“…Regarding criteria and construct validity, the BRICA scores demonstrated a strong correlation with cognitive assessment scales used in previous studies investigating Brazilian Indigenous populations. 13,15 Moreover, it effectively distinguished between individuals with unimpaired cognition and dementia patients. A cut-off score of ≤ 33 for dementia demonstrated exceptional sensitivity (94.44%) and specificity (99.2%), aligning with the performance of the KICA-Cog adaptation in Canadian Indigenous populations.…”

“…13 The evidence of dementia prevalence in these countries was obtained using verbal assessment tests validated for low-educated groups but not culturally adapted for use in Indigenous populations. [13][14][15][16][17] In Brazil, prevalence studies have been conducted using traditional cognitive tests, with a cut-off point adjusted according to education and two standard deviations below the average for the general older population. 15,18 Despite the metric adjustment made to cut-off scores controlling for the education level of older Indigenous participants, this strategy fails to address the need to culturally adapt the elements of the scales (e.g., phrases, figures, tasks) and, thus, cannot measure cognition correctly because of the inclusion of elements that hold no meaning to Indigenous culture.…”

“…[13][14][15][16][17] In Brazil, prevalence studies have been conducted using traditional cognitive tests, with a cut-off point adjusted according to education and two standard deviations below the average for the general older population. 15,18 Despite the metric adjustment made to cut-off scores controlling for the education level of older Indigenous participants, this strategy fails to address the need to culturally adapt the elements of the scales (e.g., phrases, figures, tasks) and, thus, cannot measure cognition correctly because of the inclusion of elements that hold no meaning to Indigenous culture. Preserving the culture is essential to building trustful relationships and improving accessibility and usability to health-care resources.…”