Psychometric Comparisons of 4 Measures for Assessing Upper-Extremity Function in People With Stroke

Abstract

Functional limitation of the upper extremities is common in patients with stroke. An upper-extremity measure with sound psychometric properties is indispensable for clinical and research use. The purpose of this study was to compare the psychometric properties of 4 clinical measures for assessing upper-extremity motor function in people with stroke: the upper-extremity subscale of the Fugl-Meyer Motor Test (UE-FM), the upper-extremity subscale of the Stroke Rehabilitation Assessment of Movement, the Action Research Arm Test (ARAT), and the Wolf Motor Function Test. This was a prospective, longitudinal study. Fifty-three people with stroke were evaluated with the 4 measures at 4 time points (14, 30, 90, and 180 days after stroke). Thirty-five participants completed all of the assessments. The ceiling and floor effects, validity (concurrent validity and predictive validity), and responsiveness of each measure were examined. Interrater reliability and test-retest reliability also were examined. All measures, except for the UE-FM, had significant floor effects or ceiling effects at one or more time points. The Spearman rho correlation coefficient for each pair of the 4 measures was > or =.81, indicating high concurrent validity. The predictive validity of the 4 measures was satisfactory (Spearman rho, > or =.51). The responsiveness of the 4 measures at 14 to 180 days after stroke was moderate (.52 < or = effect size < or = .79). The 4 measures had good interrater reliability (intraclass correlation coefficient [ICC], > or =.92) and test-retest reliability (ICC, > or =.97). Only the minimal detectable changes of the UE-FM (8% of the highest possible score) and the ARAT (6%) were satisfactory. The sample size was too small to conduct data analysis according to type or severity of stroke. In addition, the timed component of the Wolf Motor Function Test was not used in this study. All 4 measures showed sufficient validity, responsiveness, and reliability in participants with stroke. The UE-FM for assessing impairment and the ARAT for assessing disability had satisfactory minimal detectable changes, supporting their utility in clinical settings.