Development and Validation of the Alzheimer’s Questionnaire

This series of studies was carried in order to develop and validate the Alzheimer’s Questionnaire (AQ). The underlying rationale for the creation of the AQ was to provide clinicians with a brief and easy-to-use informant-based assessment of symptoms associated with Alzheimer’s disease (AD). Initial studies of the AQ found that it has both high sensitivity and high specificity for differentiating individuals with AD and its prodrome, amnestic mild cognitive impairment (MCI). The AQ’s accuracy in identifying MCI was explored further in an additional study which sought to determine which items on the AQ were best predicted the presence of MCI. Four items were strongly associated with MCI which were: repetition of statements and/or questions [OR = 13.20 (3.02, 57.66)]; trouble knowing the day, date, month, year, and time [OR = 17.97 (2.63, 122.77)]; difficulty managing finances [OR = 11.60 (2.10, 63.99)]; and decreased sense of direction [OR = 5.84(1.09, 31.30)]. Concurrent validity was established through another study which found that the AQ correlated moderately with the MMSE (r = -0.56) and MoCA (r = -0.46) while a strong correlation (r = 0.79) was found with the Clinical Dementia Rating Sum of Boxes (CDR-SOB). Additional work found that the AQ correlated well with formal neuropsychological measures of episodic memory and executive function. Longitudinal analyses found that was AQ was a significant predictor of clinically meaningful decline as measured by the changes in CDR Global Score (OR = 1.20, 95% CI: 1.09, 1.32; p<0.001). In addition, AQ identified clinically meaningful change among MCI cases at a greater rate(24%) than the MMSE (17%). This series of studies demonstrates that the AQ is an accurate instrument that correlates well with known measures of MCI and AD.