A Self-Report Risk Index to Predict Occurrence of Dementia in Three Independent Cohorts of Older Adults: The ANU-ADRI: e86141

• Published in: PloS one Vol. 9; no. 1
• Main Authors: Anstey, Kaarin J, Cherbuin, Nicolas, Herath, Pushpani M, Qiu, Chengxuan, Kuller, Lewis H, Lopez, Oscar L, Wilson, Robert S, Fratiglioni, Laura
• Format: Journal Article
• Language: English
• Published: 01.01.2014
• Subjects: Australia
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0086141

Background and Aims The Australian National University AD Risk Index (ANU-ADRI, http://anuadri.anu.edu.au) is a self-report risk index developed using an evidence-based medicine approach to measure risk of Alzheimer's disease (AD). We aimed to evaluate the extent to which the ANU-ADRI can predict the risk of AD in older adults and to compare the ANU-ADRI to the dementia risk index developed from the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study for middle-aged cohorts. Methods This study included three validation cohorts, i.e., the Rush Memory and Aging Study (MAP) (n = 903, age greater than or equal to 53 years), the Kungsholmen Project (KP) (n = 905, age greater than or equal to 75 years), and the Cardiovascular Health Cognition Study (CVHS) (n = 2496, age greater than or equal to 65 years) that were each followed for dementia. Baseline data were collected on exposure to the 15 risk factors included in the ANU-ADRI of which MAP had 10, KP had 8 and CVHS had 9. Risk scores and C-statistics were computed for individual participants for the ANU-ADRI and the CAIDE index. Results For the ANU-ADRI using available data, the MAP study c-statistic was 0.637 (95% CI 0.596-0.678), for the KP study it was 0.740 (0.712-0.768) and for the CVHS it was 0.733 (0.691-0.776) for predicting AD. When a common set of risk and protective factors were used c-statistics were 0.689 (95% CI 0.650-0.727), 0.666 (0.628-0.704) and 0.734 (0.707-0.761) for MAP, KP and CVHS respectively. Results for CAIDE ranged from c-statistics of 0.488 (0.427-0.554) to 0.595 (0.565-0.625). Conclusion A composite risk score derived from the ANU-ADRI weights including 8-10 risk or protective factors is a valid, self-report tool to identify those at risk of AD and dementia. The accuracy can be further improved in studies including more risk factors and younger cohorts with long-term follow-up.