Diagnosing dementia: Interrater reliability assessment and accuracy of theNINCDS/ADRDA criteria versus CERAD histopathological criteria for Alzheimer's disease

We investigated the interrater reliability and accuracy of two independent medical doctors in using NINCDS/ADRDA criteria to classify 82 elderly subje cts enrolled in OPTIMA, a longitudinal study investigating dementia. Kappa statistics revealed moderate agreement (0.5) in overall classification of d ementia type, and almost perfect agreement (0.9) on the absence or presence of dementia. Combining NINCDS/ADRDA 'possible' and 'probable' Alzheimer's disease (AD) categories produced substantial agreement (0.7). Comparison wi th CERAD histopathological criteria for AD showed that combining 'possible' and 'probable' AD resulted in a high sensitivity and accuracy, but a low s pecificity. To increase specificity, the NINCDS/ADRDA 'probable AD' categor y should be used alone. An important finding was that the accuracy of diagn oses of AD made from the case notes alone was not different from the diagno ses obtained following active involvement with participants. Copyright (C) 2000 S. Karger AG, Basel.