Psychometric Testing and Clinical Utility of a Modified Version of the Function in Sitting Test for Individuals With Chronic Spinal Cord Injury

Abstract

ObjectivesSeated balance (SB) is substantially compromised and greatly impacts the function of individuals living with a spinal cord injury (SCI). A clinically applicable criterion standard measure for SB does not exist for this population. Initial validation and reliability analysis of the Function in Sitting Test (FIST) in SCI has been published, but the authors of this study report that modifications to the tool may be necessary. This study aimed to explore the psychometrics and clinical utility of a modified version of the FIST to better measure SCI-specific functional tasks in sitting. DesignThe FIST was modified (FIST-SCI) by an expert panel and used by 2 graders to evaluate the SB of individuals with chronic SCI (cSCI) on 2 separate days. The Motor Assessment Scale item 3 (MAS-SCI) was included as a comparison measure. SettingResearch facility. ParticipantsIndividuals with cSCI longer than 1 year (N=38) participated in the study. Injury levels of individuals participating in this study spanned C1 to T10 (American Spinal Injury Association Impairment Scale A, 17 subjects; B, 12 subjects; and C, 9 subjects). Thirteen individuals required assistance to transfer. InterventionsNot applicable. Main Outcome MeasuresValidity, reliability, internal consistency, sensitivity, specificity, and responsiveness. ResultsValidity testing found a moderate relationship between the MAS-SCI and the FIST-SCI (ρ, .522; P<.05). FIST-SCI scores distinguished individuals requiring assistance to transfer from those who were independent (t=4.51; P<.05). Inter- and intra-rater reliability were excellent (intraclass correlation coefficient (2,k)=.985 and .983, respectively) and internal consistency was excellent (α=.94). A FIST-SCI cutoff score of 45 or greater was 92% sensitive and specific in characterizing transfer ability. Standard error of the measure (1.3) and minimal detectable change (3.5) were similar to previous work. ConclusionsInitial validity of the FIST-SCI is reported, but further assessment is required. Reliability is excellent in the cSCI population. FIST-SCI scores provide clinical insight into the seated functional ability of individuals with cSCI.