An Effort Index for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)

Abstract

The present study aimed to develop an internal validity indicator for a brief general purpose screening battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Two subtests of the RBANS were predicted to be relatively resilient to cognitive dysfunction on the basis of previous research. An Effort Index (EI) was created by combining them via a scaling system. The frequency of EI scores was first examined in a heterogenous clinical sample. A subsequent validation study showed good discriminability. In conclusion, the EI appears to be useful for detecting insufficient effort on a screening battery.

Notes

MTBI = Mild traumatic brain injury; Sim = Simulated.

^a n = 32

^b n = 24

^c n = 15

^d n = 28

^e n = 24

¹Interestingly, there was minimal difference between the receiver operating characteristic curves of the Digit Span (area under the curve = .844, standard error = .040, 95% confidence interval = .767 to .922), List Recognition (area under the curve = .908, standard error = .032, 95% confidence interval = .846 to .970), and EI variables. That is, the discriminability of the individual cut-offs for the Digit Span and List Recognition subtests was no better or worse than that of the EI across the complete range of cut-off points. However, because they will very often produce discrepant (and irreconcilable) classification outcomes and have an unacceptably high cumulative false positive rate, their use is not recommended.

²Note that it may be possible to achieve superior discriminability between these groups using an alternative approach that capitalizes on patterns unique to TBI, such as preserved recall of prose passages relative to word lists (Bayless, Hamilton, & Roberts, 1995). However, the goal of the present study was to develop an internal validity indicator that would be maximally insensitive to a wide rage of cognitive disorders.