High-Level Mobility Assessment Tool (HiMAT): interrater reliability, retest reliability, and internal consistency.

The High-Level Mobility Assessment Tool (HiMAT) assesses high-level mobility in people who have sustained a traumatic brain injury (TBI). The purpose of this study was to investigate the interrater reliability, retest reliability, and internal consistency of data obtained with the HiMAT. Three physical therapists and 103 people with TBI were recruited from a rehabilitation hospital. Three physical therapists concurrently assessed a subset of 17 subjects with TBI to investigate interrater reliability. One physical therapist assessed a different subset of 20 subjects with TBI on 2 occasions, 2 days apart, to investigate retest reliability. Data from the entire sample of 103 subjects were used to investigate the internal consistency of this new scale. Both the interrater reliability (intraclass correlation coefficient [ICC]=.99) and the retest reliability (ICC=.99) of the HiMAT data were very high. For retest reliability, a small systematic change was detected (t=3.82, df=19), indicating a marginal improvement of 1 point at retest. Internal consistency also was very high (Cronbach alpha=.97). The HiMAT is a new tool specifically designed to measure high-level mobility, which currently is not a component of existing scales used in TBI. This study demonstrated that the HiMAT is a reliable tool for measuring high-level mobility.