Validation of the neurobehavioral cognitive status examination and the Rivermead Behavioural Memory Test in investigations of dementia.

The aim of this retrospective study was to validate two commonly used instruments, Cognistat and the Rivermead Behavioural Memory Test, RBMT, for detection of MCI and mild dementia. Two different diagnosis groups, mild cognitive impairment (MCI) and Alzheimer's disease combined with mixed dementia representing mild dementia (MD), were compared with a group of patients who did not receive a diagnosis of dementia. All patients were assessed at a specialized outpatient memory clinic in a university hospital in Sweden using the Mini Mental State Examination (MMSE), Cognistat, and RBMT. Sensitivity, specificity, predictive value, and likelihood ratio were calculated for the tests. The Cognistat and RBMT have moderate validity in the detection of MCI and mild dementia. On their own, none of the tests used is sufficient for diagnosing MCI or mild dementia. A combination of the Cognistat and RBMT provides additional information in early stage dementia; in this regard the RBMT is better than the Cognistat, which also has other limitations. The RBMT can be helpful for distinguishing between MCI and mild dementia. There is a need for a more sensitive screening test to capture early cognitive impairment related to patients' occupational performance and problems in daily life.