Measuring upper limb capacity in patients after stroke: reliability and validity of the stroke upper limb capacity scale

OBJECTIVE: To investigate the interrater reliability and construct validity of the Stroke Upper Limb Capacity Scale (SULCS). DESIGN: Cohort study. SETTING: Inpatient department of a rehabilitation center. PARTICIPANTS: Patients after stroke (N=21; mean age +/- SD, 61.7 +/- 7.9y; 57% men), undergoing inpatient rehabilitation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The SULCS was administered by occupational therapists (OTs) within 6 weeks after stroke (t1), 3 months after t1 by the same OT (t2), and within 1 week after t2 by another OT (t3). Interrater reliability, the repeatability between different raters, was assessed by calculating the intraclass correlation coefficient (ICC) based on the scores at t2 and t3. Construct validity, indicating agreement with hypotheses concerning the construct that is being measured, was assessed with Spearman rank correlation coefficient (rho). The SULCS scores were cross-sectionally correlated with those of the Action Research Arm Test (ARAT) and the Rivermead Motor Assessment (RMA) at t1, and longitudinally with the respective change scores between t1 and t2. RESULTS: The SULCS (range, 0-10) had a high ICC (.94; 95% confidence interval, .86-.97) and strong cross-sectional correlation with both the ARAT and the RMA (rho=.91 and rho=.85, respectively), while the respective change scores showed a strong correlation with the ARAT (rho=.71) and a moderate correlation with the RMA (rho=.48). CONCLUSIONS: The SULCS has good interrater reliability and construct validity