Rey Tangled Line Test: A measure of processing speed in TBI.

The study had 100 participants with TBI and no healthy or orthopedic control group, so it cannot show how well the test separates TBI from normal performance. The moderate/severe group included only 9 people with severe TBI, so severity comparisons may miss true differences. Participants were tested between 30 days and 5 years after injury, a wide range, although time since injury was not related to RTLT scores. RTLT accuracy had very little spread: 75% got all trials correct, so it was not useful in the factor analysis and may not be a sensitive measure. The factor analysis was exploratory, and RTLT latency also linked to motor tests, so the test is not a pure processing-speed measure. Not all participants completed the whole battery, and missing data were handled pairwise, so different analyses may have used different numbers of participants. The latency scores were skewed, suggesting a possible ceiling effect, and updated normative data are needed. The error-group comparisons were post-hoc and involved multiple other tests, so they need confirmation.

The authors declared no conflicts of interest. The paper does not state who funded the research.

Do not use the Rey Tangled Line Test to judge TBI severity or to diagnose cognitive impairment. Test scores did not differ between mild and moderate/severe groups, and the study had no healthy control group.