The CERAD neuropsychological assessment battery total score detects and predicts Alzheimer disease dementia with high diagnostic accuracy

Objectives: To establish the diagnostic accuracy of the Total Score of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological assessment battery (CERAD-NP) both for cross-sectional discrimination of Alzheimer disease (AD) dementia and short-term prediction of incident AD dementia.

Design: Longitudinal cohort study with two assessments at a 1.5-year interval.

Setting: Primary care sample randomly recruited via medical record registries.

Participants: As part of the German Study on Ageing, Cognition, and Dementia (AgeCoDe), a sample of elderly individuals (N = 1,606; mean age: 84 years) was assessed.

Measurements: Subjects were assessed with the CERAD-NP and followed up for 18 months (97.6% follow-up rate). Logistic regression and receiver-operating-characteristic (ROC) curve analysis were used to compare the diagnostic accuracy of the CERAD-NP Total Score (CTS) with that of single CERAD-NP scores and the Mini-Mental-State-Examination (MMSE) score.

Results: ROC curve analysis resulted in excellent (area under the curve [AUC]: 0.97) cross-sectional discrimination between non-AD and AD dementia subjects. Prediction of incident AD dementia with the CTS was also very good (AUC: 0.89), and was significantly better than prediction based on the MMSE.

Conclusions: The cross-sectional results confirm that the CTS is a highly accurate diagnostic tool for detecting AD dementia in elderly primary care patients. In addition, we provide evidence that the CTS is also accurate for the prediction of incident AD dementia. These findings further support the validity of the CTS as an index of overall cognitive functioning for detection and prediction of AD dementia.