Telephone screening for mild cognitive impairment in hispanics using the Alzheimer's questionnaire

BACKGROUND/STUDY CONTEXT: There is a need for a simple and reliable screening test to detect individuals with mild cognitive impairment (MCI). The authors analyzed the relationship between performance of the Alzheimer's Questionnaire (AQ), an informant-rated measure of dementia-related behaviors, relative to the Telephone Interview for Cognitive Status-modified (TICS-m), Memory Impairment Scale-telephone version (MIS-t), and the Telephone Executive Assessment (TEXAS) as predictors of MCI.

Comparative cross-sectional design, with data collected from participants in the Texas Alzheimer's Research and Care Consortium's (TARCC) San Antonio site. One-hundred percent of our sample was Hispanic. The San Antonio subset of TARCC sample is highly enriched with Mexican Americans (MAs). Fifty-five percent of the interviews were conducted in Spanish. Of the 184 persons enrolled, 124 were normal controls (NCs), and 60 participants had MCI. MCI status and Clinical Dementia Rating Scale Sum of Boxes (CDR-SOB) were determined through clinical consensus and performed blind to telephone assessments. Controlling for age, gender, education, and language of interview, the association between telephone measures and CDR-SOB was evaluated by multivariate regression.

AQ scores were not affected by education, gender, and language of interview, but subject's age did show a positive correlation with informant AQ ratings. The AQ predicted CDR-SOB independently of the cognitive measures, adding variance above and beyond demographics. The TICS-m and the TEXAS appear to have additive value in improving the detection of cognitively impaired patients. The MIS-t failed to contribute significantly to CDR-SOB, independent of the other measures.

The AQ may have utility as a culture-fair telephone screening for MCI. The AQ was able to modestly distinguish MCI from NCs. The TEXAS adds variance to a model of dementia severity independent of the AQ, suggesting that the latter may weakly assess that cognitive domain (executive control function). On the other hand, the AQ attenuates the MIS-t effect. This suggests a prominent AQ bias in favor of detecting memory impairment. Additional studies are required to determine if the AQ can distinguish between amnestic and dysexecutive MCI subtypes, or between MCI and Alzheimer's disease in Hispanics.