Assesing motor impairment of the trunk in patients with traumatic brain injury: reliability and validity of the trunk impairment scale

Abstract

Introduction: Literature regarding trunk assessment after Traumatic Brain Injury (TBI) is limited. The Trunk Impairment Scale (TIS) is a newly developed tool which is intended to assess static and dynamic sitting balance and trunk co-ordination.Aim: It was the aim of this study to examine the reliability andvalidity of the TIS in TBI patients.Methods: Thirty TBI subjects were recruited from within arehabilitation setting. Two researchers observed each subjectsimultaneously, but scored independently. Each subject wasre-examined by one of the raters.Results: Kappa and weighted kappa values for all items ranged from 0.34 to 1. All percentages of agreement were 70% or higher. Intraclass correlation (ICC) coefficients for the sub-scale scores were between 0.72 and 0.88. Test-retest and inter-rater reliability for the total TIS score (ICC) was 0.88 and 0.95, respectively. The 95% limits of agreement for the test-retest and interexaminer measurement error interval were -4,4 and -3,3, respectively. The construct validity was evaluated by means of the Spearman rank correlation coefficient between the TIS and the Barthel Index (r=0.59, p=.0007).Discussion and conclusion: Fair to perfect item agreement was found but the reliability of certain items requiresfurther attention. Acceptable sub-scale and total TIS reliability and validity justify the use of the TIS in TBI treatmentand research.