Development and validation of a brief dementia risk assessment tool for use in primary care

Abstract

Undiagnosed dementia is common in older adults, and detection of 'any cognitive impairment' is now federally mandated as part of the Medicare Annual Wellness Visit. Yet screening all older adults for cognitive impairment may result in unacceptably high false positive rates, particularly in younger Medicare patients. The objective of our study was to develop and validate a brief Dementia Risk Assessment (DRA) tool for use in primary care to enable clinicians to identify high-risk patients who should be targeted for cognitive screening. The DRA was developed and validated using data from four existing cohort studies: the Cardiovascular Health Study (CHS), Framingham Heart Study (FHS), Health and Retirement Study (HRS), and Sacramento Area Latino Study on Aging (SALSA). These studies were selected because they included data on incident dementia and a broad palette of potential risk markers and together provided representation of individuals from diverse geographic and race/ethnic backgrounds. We first calculated 6-year dementia risk as a function of age and set ≥80 years as the age at which cognitive screening should be considered based on age alone. In participants age 65–79 years, we then performed Cox proportional hazards analyses and used an iterative process to identify a common set of dementia risk predictors. Meta-analysis was performed to develop a DRA point score based on the predictors retained in the final model. The final DRA tool included age (1 point/year), <12 years education (9 points), stroke (6 points), diabetes mellitus (3 points), body mass index <18.5 kg/m 2 (8 points), requiring assistance with money or medications (10 points), and evidence of depression (anti-depressant use or self-reporting “everything an effort” ≥3 days/week, 6 points). Accuracy based on Harrell's c statistic (95% confidence interval) was CHS, 0.68 (0.65, 0.72); FHS, 0.77 (0.73, 0.82); HRS, 0.76 (0.74, 0.77); and SALSA, 0.78 (0.72, 0.83). Across all 4 studies, a point-value of ≥22 identified a group of 65–79 year-olds whose 6-year dementia risk was comparable to 80–84 year-olds. The DRA is a simple tool that can be used in primary care to identify older patients with an increased risk of developing dementia who should be considered for cognitive screening.