Brain Injury Screening Tool (BIST): test-retest reliability in a community adult sample.

OBJECTIVE: To determine the test-retest reliability of the Brain Injury Screening Tool (BIST), which was designed to support the initial assessment of mild traumatic brain injury (mTBI) across a variety of contexts, including primary and secondary care. DESIGN: Test-retest design over a 2-week period. SETTING: Community based. PARTICIPANTS: Sixty-eight adults (aged 18-58 years) who had not experienced an mTBI within the last 5 years and completed the BIST on two different occasions. MEASURES: Participants were invited to complete the 15-item BIST symptom scale and the Depression, Anxiety and Stress Scale (DASS-21) online at two time-points (baseline and 2 weeks later). To account for large variations in mood affecting symptom reporting, change scores on the subscales of the DASS-21 were calculated, and outliers were removed from the analysis. RESULTS: The BIST total symptom score and subscale scores (physical-emotional, cognitive and vestibular) demonstrated moderate to good test-retest reliability with intraclass correlation coefficients ranging between 0.51 and 0.83. There were no meaningful differences between symptom reporting on the total scale or subscales of the BIST between time1 and time2 at the p<0.05 level when calculated using related samples Wilcoxon signed-rank tests. CONCLUSION: The BIST showed evidence of good stability of symptom reporting within a non-injured, community adult sample. This increases confidence that changes observed in symptom reporting in an injured sample are related to actual symptom change rather than measurement error and supports the use of the symptom scale to monitor recovery over time. Further research is needed to explore reliability of the BIST within those aged <16 years.

The Brain Injury Screening Tool (BIST): Tool development, factor structure and validity.

Currently health care pathways (the combination and order of services that a patient receives to manage their injury) following a mild traumatic brain injury vary considerably. Some clinicians lack confidence in injury recognition, management and knowing when to refer. A clinical expert group developed the Brain Injury Screening Tool (BIST) to provide guidance on health care pathways based on clinical indicators of poor recovery. The tool aims to facilitate access to specialist services (if required) to improve longer term prognosis. The tool was developed using a three-step process including: 1) domain mapping; 2) item development and 3) item testing and review. An online retrospective survey of 114 adults (>16 years) who had experienced a mild brain injury in the past 10 years was used to determine the initial psychometric properties of the 15-item symptom scale of the BIST. Participants were randomised to complete the BIST and one of two existing symptom scales; the Rivermead Post-concussion Symptom Questionnaire (RPQ) or the Sports Concussion Assessment Test (SCAT-5) symptom scale to determine concurrent validity. Participant responses to the BIST symptom scale items were used to determine scale reliability using Cronbach's alpha. A principal components analysis explored the underlying factor structure. Spearman's correlation coefficients determined concurrent validity with the RPQ and SCAT-5 symptom scales. The 15 items were found to require a reading age of 6-8 years old using readability statistics. High concurrent validity was shown against the RPQ (r = 0.91) and SCAT-5 (r = 0.90). The BIST total symptom scale (α = 0.94) and the three factors identified demonstrated excellent internal consistency: physical/emotional (α = 0.90), cognitive (α = 0.92) and vestibular-ocular (α = 0.80). This study provides evidence to support the utility, internal consistency, factor structure and concurrent validity of the BIST. Further research is warranted to determine the utility of the BIST scoring criteria and responsiveness to change in patients.