Measurement properties of the wheelchair outcome measure in individuals with spinal cord injury

Abstract

One-week retest methodological study. To assess the reliability and validity of the wheelchair outcome measure (WhOM) in a sample of individuals with spinal cord injury (SCI). Vancouver, British Columbia, Canada. The WhOM measures the impact of wheelchair interventions on a user's self-selected participation outcomes. The WhOM was administered to 50 participants on two occasions by the same rater, 1 week apart, to assess test-retest reliability. To determine inter-rater reliability, the WhOM was administered a third time approximately 72 h later by a different rater. Validity was evaluated by correlating scores from the WhOM with scores from the Assessment of Life Habits (LIFE-H). The test-retest intraclass correlation coefficients (ICC(2, 2)) for the WhOM satisfaction (Sat) and WhOM importance (Impt) × Sat scores were 0.83 (95% confidence interval (CI), 0.72-0.90) and 0.88 (95% CI, 0.79-0.93), respectively. The inter-rater ICC for the WhOM Sat and WhOM Impt × Sat scores were 0.91 (95% CI, 0.85-0.95) and 0.90 (95% CI, 0.83-0.94), respectively. As hypothesized, most scores on the WhOM were fair to moderate (r=0.3-0.5) and positively correlated with scores on the LIFE-H. The WhOM is a new outcome measure that demonstrates good reliability and validity among individuals with SCI. It is designed to assist wheelchair users identify and evaluate the impact of wheelchair interventions on participation level outcomes. The WhOM may be applicable for clinical- or research-oriented purposes.