Reliability of the Clinical Outcome Variables Scale When Administered Via Telephone to Assess Mobility in People With Spinal Cord Injury

Abstract Barker RN, Amsters DI, Kendall MD, Pershouse KJ, Haines TP. Reliability of the Clinical Outcome Variables Scale when administered via telephone to assess mobility in people with spinal cord injury. Objective To examine the equivalence reliability and test-retest reliability of the Clinical Outcome Variables Scale (COVS) when administered via telephone (TCOVS) to people with spinal cord injury (SCI). Design Equivalence (telephone administration vs in-person) and test-retest reliability study. Setting Assessments conducted in participants’ home environment. Participants Equivalence reliability was examined in a convenience sample of 37 people with a diagnosis of traumatic SCI who had been discharged from the Queensland Spinal Injuries Unit to the community. In a separate group of participants, test-retest reliability of COVS when administered via telephone was examined in 43 people with SCI who were randomly selected from the Queensland Spinal Cord Injuries Service records. Interventions Not applicable. Main Outcome Measures Reliability was assessed at the subscale and composite score level using intraclass correlation coefficients (ICC2,1 ) and Bland-Altman limits of agreement. Results Reliability was good for TCOVS and COVS for the composite score (ICC=.98), mobility subscale (ICC=.97), and ambulation subscale (ICC=.99). Reliability was also good for TCOVS test and retest assessments for the composite score (ICC=1), mobility subscale (ICC=1), and ambulation subscale (ICC=1). For all comparisons, most data points were within the 95% limits of agreement and the width of limits of agreement were considered to be clinically acceptable. Conclusions The study findings confirm the equivalence and test-retest reliability of the TCOVS in an SCI population when administered by trained raters.