Validation of the neuropsychological assessment battery screening measure (NAB-S) in participants with traumatic brain injury

Background: This study validates the Neuropsychological Assessment Battery Screening Tool (NAB-S) against a battery of established neuropsychological tests, used as a convergent validity test battery (CVTB). Method: Forty-four participants with traumatic brain injury (TBI) were recruited from an outpatient clinic at a UK trauma centre and residential rehabilitation centre. The NAB-S and CVTB were administered to the sample. Results: Strong positive correlations were observed between NAB-S indices and NAB-S TBI index in comparison with indices for distinct cognitive domains from the CVTB, and the convergent validity test battery mean (CVTBM). There was a high collinearity between NAB-S subtest indices, and poor internal consistency for some indices. Semi-partial correlations revealed the unique variance between NAB-S and CVTB indices, which were highly significant for the NAB-S attention and memory indices. An area under the receiver operator characteristic curve (AUROC) revealed that the NAB-S and NAB-S TBI indices are highly predictive of impairment measured by the CVTB. Conclusions: The NAB-S has good predictive validity of overall impairment as measured by the CVTB and is an adequate screen of cognitive impairment following TBI. Some indices had poor internal consistency and high collinearity, suggesting that further assessment with more sophisticated tests would be warranted