Inter- and intra-rater reliability of the GAITRite system among individuals with sub-acute stroke

Abstract

Technology-based assessment tools with semi-automated processing, such as pressure-sensitive mats used for gait assessment, may be considered to be objective; therefore it may be assumed that rater reliability is not a concern. However, user input is often required and rater reliability must be determined. The purpose of this study was to assess the inter- and intra-rater reliability of spatial and temporal characteristics of gait in stroke patients using the GAITRite system. Forty-six individuals with stroke attending in-patient rehabilitation walked across the pressure-sensitive mat 2-4 times at preferred walking speeds, with or without a gait aid. Five raters independently processed gait data. Three raters re-processed the data after a delay of at least one month. The intraclass correlation coefficients (ICC) and 95% confidence intervals of the ICC were determined for velocity, step time, step length, and step width. Inter-rater reliability for velocity, step time, and step length were high (ICC>0.90). Intra-rater reliability was generally greater than inter-rater reliability (from 0.81 to >0.99 for inter-rater versus 0.77 to >0.99 for intra-rater reliability). Overall, this study suggests that GAITRite is a reliable assessment tool; however, there still remains subjectivity in processing the data, resulting in no patients with perfect agreement between raters. Additional logic checking within the processing software or standardization of training could help to reduce potential errors in processing.

Keywords: Gait; Reliability of results; Stroke.