Self-report Pain Scale Reliability in Veterans and Service Members With Traumatic Brain Injuries Undergoing Inpatient Rehabilitation

Introduction Pain in trauma patients with traumatic brain injury (TBI) may heighten cognitive-behavioral impairment and impede rehabilitation efforts. Multiple self-report pain assessment tools have been shown reliable in cognitively intact adults and children but are understudied in the cognitively impaired, particularly in persons with TBI. The objective of this study was to assess the utility and reliability of four pain assessment instruments among TBI patients during inpatient rehabilitation and the influence of cognitive impairment. Methods Participants self-completed four pain intensity measures, the Verbal Descriptor Scale, Faces Pain Scale (Faces), Numerical Rating Scale (NRS), and Color-Enhanced Visual Analog Scale (CAS), during five study visits over a 2-week period. Data were collected on time to completion and most preferred pain measure. To assess scale reliability, participants re-rated their current pain. To assess scale responsiveness, standard mean response was measured across time and a worst past pain experience was rated. Cognitive impairment was assessed with the Memory, Orientation, and Amnesia Test. Results The NRS was the most preferred measure by participants at every time point in the study. Mean pain measure completion time for all measures was under 11 seconds and did not significantly change during the study period. 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. When stratified by cognitive impairment, the mean scores were consistently nominally higher for impaired participants, reaching statistical significance only for the CAS and Faces at baseline. In the cognitive impaired group, reliability for the Faces showed some weakening, as did the VAS to a milder degree. Conclusions 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 NRS was the most preferred by patients, regardless of cognitive impairment level.