The validity of the NART-RSPM index in detecting intellectual decline following traumatic brain injury: a controlled study.

The present study replicated Van den Broek and Bradshaw's (1994) study by developing a multiple regression equation to predict Ravens Standard Progressive Matrices (RSPM) scores from participants' National Adult Reading Test (NART) scores and demographic variables. A test of the validity of this procedure was undertaken by applying both the Van den Broek and Bradshaw equation and the present study's equation to a mixed sample of orthopedic control (OC) and closed head injury (CHI) participants. Premorbid RSPM scores were estimated using both equations and then compared to obtained scores. Results indicated that both equations had good predictive accuracy in estimating RSPM scores and were able to detect significantly higher rates of impairment in general intelligence in the CHI participants (24%) compared to the OC sample (7%).