Revisiting the Common Misconceptions About Traumatic Brain Injury Scale (CM-TBI); What Does It Really Measure?

The participants were a purposive sample of people starting an online TBI course, so the sample may not represent the wider public or people with TBI. The sample was mostly female, middle-aged, university educated, and Australian: 828 were female, 598 had a bachelor degree or above, and 647 lived in Australia. The revised scale has restricted coverage: it includes only one item specifically mentioning voluntary motor function, and it does not consider other speech or involuntary motor changes. The scale does not include sensory changes or biological functions such as sleep. No items on cognition or memory from the original scale were retained. Items about acute response to injury, such as consciousness, were not retained. The authors used classical test theory only, so they did not perform item-level analysis that Rasch or other item response theory methods would allow. The authors recommend future studies assess test-retest reliability or convergent validity, so these properties were not established in this paper. The scale mixes knowledge and misconceptions, and the paper says existing scales do not clearly separate the two constructs.

Do not treat the revised scale as a patient assessment or as evidence that it measures all important TBI domains. It was tested in people starting an online course, and the authors state that its coverage is restricted.