The Vulnerability Index: A weighted measure of dementia and cognitive impairment risk

Abstract

Introduction: A brief, easily calculated and interpretable index to assess vulnerability to developing cognitive impairment is needed in clinical practice and research. To address this, we developed the Vulnerability Index (VI) with the goal of identifying individuals possessing a high risk for cognitive impairment.

Methods: Twelve easily obtained sociodemographic, medical, and functional factors were used to develop the VI, with each selectively weighted based on factor analysis and predictive modeling. This cross-sectional study examined 387 subject-partner dyads.

Results: The VI was found to accurately discriminate between cognitively normal controls and participants with cognitive impairment (area under the curve [AUC]: 0.844; 95% confidence interval [CI]: 0.776-0.913) and individuals scoring high on the VI (≥8) had worse health, functional, behavioral, cognitive, and quality of life ratings than those with lower scores.

Discussion: The VI could be used in screening asymptomatic individuals for risk of cognitive impairment and guiding the development of primary and secondary prevention plans.

Keywords: Alzheimer's disease; cognitive impairment; dementia; functional assessments; health records; primary prevention; risk assessment; screening; sociodemographics.

FIGURE 1

A) A split histogram depicting the number of subjects from each impairment group for each score in the Vulnerability Index (VI). (B) Curves highlighting the distribution of the VI for each impairment group. The distribution of the dementia group was not skewed, whereas the curves for both the mild cognitive impairment (MCI) and Control groups are skewed, with the majority of these subjects exhibiting lower values of the VI and tapering off toward the higher end of the scale. (C) A stacked histogram showing the overall distribution of the VI