Brief report: Utility of a demographic equation in detecting impaired NART performance after TBI

OBJECTIVES: This study applies a demographic regression equation devised by Crawford, Allan, Cochrane, and Parker (1990) to determine its utility in New Zealand, and to determine the proportion of persons with traumatic brain injury (TBI) with impaired performance on the National Adult Reading Test (NART). METHOD: The NART was administered to 80 community participants, 65 people with traumatic brain injury (TBI), and 27 orthopaedic controls. The Crawford et al. (1990) equation was applied to all three samples. RESULTS: The Crawford et al. (1990) equation was applicable in the New Zealand community sample. It was found that 30% of the TBI sample had impaired performance on the NART. Using corrected NART scores, a significantly larger proportion of the TBI sample was detected as intellectually impaired than in the control sample. CONCLUSION: Nearly one-third of the TBI sample evidenced impaired performance on the NART. Consequently, clinicians that use the NART in assessing people with TBI should use the demographic equation to check the accuracy of NART performances, and correct the NART scores if this is indicated.