RICHMOND, VA—Cognitive-behavioral impairment can be intensified by pain in traumatic brain injury patients and impede rehabilitation efforts, according to a new study. While multiple self-report pain assessment tools are proven reliable in cognitively intact adults and children, those have been understudied in the cognitively impaired, especially in TBI patients, it adds.

The study in Military Medicine sought to assess the utility and reliability of four pain assessment instruments among TBI patients during inpatient rehabilitation and the influence of cognitive impairment.1

For the study led by Hunter Holmes McGuire VAMC-led researchers, participants self-completed four pain intensity measures, the Verbal Descriptor Scale, Faces Pain Scale, Numerical Rating Scale and Color-Enhanced Visual Analog Scale, during five study visits over a two-week period. The study team collected data on time to completion and most preferred pain measure.

In addition, to assess scale reliability, participants re-rated their current pain. To assess scale responsiveness, researchers measured mean response across time and a worst past pain experience was rated. Cognitive impairment, meanwhile, was assessed with the Memory, Orientation and Amnesia Test.

The numeric rating scale was the most preferred measure by participants at every time point in the study, with mean pain measure completion time for all measures remaining less than 11 seconds and not significantly varying during the study period.

The authors pointed out that all scales showed very high test-retest reliability, with very strong correlations. Standard mean response from Day 0 to 14 ranged from 0.387 to 0.532 across the scales, they said.

When stratified by cognitive impairment, the mean scores were consistently nominally higher for impaired participants, reaching statistical significance only for the color analogue scale and Faces at baseline. In the cognitively-impaired group, reliability for the Faces showed some weakening, as did the visual analogue scale to a lesser degree, according to the study team.

“All four pain measures demonstrated good utility, very high test-retest reliability, and satisfactory responsiveness. Greater cognitive impairment was associated with elevated pain ratings, especially in the Faces and CAS,” the study authors concluded. “The NRS was the most preferred by patients, regardless of cognitive impairment level.”

1.Hoot MR, Khokhar B, Walker WC. Self-report Pain Scale Reliability in Veterans and Service Members With Traumatic Brain Injuries Undergoing Inpatient Rehabilitation. Mil Med. 2019 Sep 9. pii: usz272. doi: 10.1093/milmed/usz272.[Epub ahead of print] PubMed PMID: 31498391.