Ceiling and floor effects on the Rivermead Behavioural Memory Test in patients with alcohol-related memory disorders and healthy participants

Objective. The Rivermead Behavioural Memory Test (RBMT) is a widely used measure of everyday memory performance. In the most recent revision of this test (RBMT-3) some important changes have been made compared with the RBMT. This study examines whether this revision has improved the quality of the clinical classifications using this test, as well as the frequency of floor and ceiling performances that were prominent on some subtests of the RBMT, using a heterogeneous study sample. Methods. Twenty-five healthy adults and 25 patients with alcohol-related memory impairment (including 15 Korsakoff patients) were examined using both the RBMT and the RBMT-3. The number of perfect scores and floor performances, as well as the percentage of individuals classified as impaired (< 5th percentile), were scored and compared. Results. Administration of the RBMT-3 results in less participants performing at or near individual subtest's ceiling, and resulted in less floor performances. Moreover, the RBMT-3 misclassifies less healthy participants as impaired than the RBMT. Conclusions. The RBMT-3 is a substantial improvement over the original RBMT, as it reduces the problem of ceiling and floor performances and the number of misclassifications. However, more research is needed on the ecological validity of the RBMT-3.