Consistency of responses on retesting among head-injured subjects in litigation versus head-injured subjects not in litigation.
The consistency of responses to individual items of the Wechsler Information, Comprehension, Arithmetic, Similarities, and Vocabulary subtests on two separate testings were compared for two groups of 20 head-injured subjects. One group of subjects was involved in litigation to recover damages for deficits allegedly resulting from the head injury; the other group was not involved in any litigation. A scoring system was devised to reflect responses that were different on the second testing, and this raw score was converted to a scaled score. The Response Consistency Index represents the sum of the scaled scores for the five subtests. The Response Consistency Index scores showed that retest responses were less consistent in the litigation group than in the non-litigation group. The best cutoff point separated the groups with accuracies of 90% (litigation group) and 100% (non-litigation group). These results suggest that the approach described in this study provides an objective method that significantly differentiates between litigants and non-litigants among head-injured subjects. It would appear that litigants, either deliberately or for other reasons, fail to produce consistent responses on successive examinations.