A Late Life Risk Index for Severe Cognitive Impairment in Mexico

Background: Several dementia risk indices have been developed for older adults in high-income countries. However, no index has been developed for populations in low- or middle-income countries. Objective: To create a risk index for predicting severe cognitive impairment among adults aged ≥60 in Mexico and to compare the accuracy of this index to the Dementia Screening Indicator (DSI). Methods: This study included 3,002 participants from the Mexican Health and Aging Study (MHAS) interviewed in 2001 and 2012. The MHAS risk index included sociodemographic, health, and functional characteristics collected in 2001. A point value based on the beta coefficients from a multivariable logistic regression model was assigned to each risk factor and the total score was calculated. Results: The MHAS risk index (AUC = 0.74 95 CI = 0.70-0.77) and DSI (AUC = 0.72 95 CI = 0.69-0.77) had similar accuracy for discriminating between participants who developed severe cognitive impairment from those who did not. A score of ≥16 on the MHAS risk index had a sensitivity of 0.69 (95 CI = 0.64-0.70) and specificity of 0.67 (95 CI = 0.66-0.69). A score of ≥23 on the DSI had a sensitivity of 0.56 (95 CI = 0.50-0.63) and specificity of 0.78 (95 CI = 0.76-0.79). Discussion: The MHAS risk index and DSI have moderate accuracy for predicting severe cognitive impairment among older adults in Mexico. This provides evidence that existing dementia risk indices may be applicable in low- and middle-income countries such as Mexico. Future research should seek to identify additional risk factors that can improve the accuracy of the MHAS risk index.