ORIGINAL ARTICLE Reliability of the Clinical Outcome Variables Scale When Administered Via Telephone to Assess Mobility in People With Spinal Cord Injury Ruth N. Barker, PhD, Delena I. Amsters, MPhyt, Melissa D. Kendall, MHumSrv, Kiley J. Pershouse, BSocWk, Terry P. Haines, PhD ABSTRACT. Barker RN, Amsters DI, Kendall MD, Per- shouse KJ, Haines TP. Reliability of the Clinical Outcome Variables Scale when administered via telephone to assess mobility in people with spinal cord injury. Arch Phys Med Rehabil 2007;88:632-7. 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 con- venience 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 (ICC 2,1 ) 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 agree- ment 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. Key Words: Outcome assessment (health care); Rehabilita- tion; Reproducibility of results; Spinal cord injuries; Telephone. © 2007 by the American Congress of Rehabilitation Medi- cine and the American Academy of Physical Medicine and Rehabilitation P EOPLE WITH TRAUMATIC spinal cord injury (SCI) can now expect to live close to a normal life span; however 1 many may experience age-related health issues at an earlier age than the general population. 2,3 To investigate these health issues, the Queensland Spinal Cord Injuries Service (QSCIS) is undertaking a longitudinal study to track changes in people with SCI across the lifespan. Assessment occurs via telephone interview, a method of data collection that is easily administered, cost effective, and inclusive of a geographically dispersed group of people. Many outcome measures that are included in the assessment are tradi- tionally administered in-person, particularly functional measures. It is necessary, therefore, to confirm that information obtained by telephone interview is similar to information obtained by in- person observation (equivalence reliability) and that information obtained by telephone interview is consistent over time (test-retest reliability). Only then can any variability in assessment findings be attributed to real change, and not simply to variability in reporting. One of the key functional outcome measures to be used in the longitudinal study is the Clinical Outcomes Variable Scale (COVS), a clinician rated, composite measure of mobility that is used routinely across the continuum of care provided by QSCIS. 4 It has also been used for general rehabilitation popu- lations and specific diagnostic groups such as stroke, traumatic brain injury, amputations, and musculoskeletal injuries, and has been applied in acute, inpatient, and outpatient rehabilita- tion settings, and community settings. 4-6 In its current form, it consists of 13 items, which comprise rolling (2 items), lying to sitting (1 item), sitting balance (1 item), transfers (2 items), ambulation (4 items), wheelchair mobility (1 item), and arm function (2 items). All 13 items are rated by a clinician through observation and assessment of task performance according to detailed guidelines. Each COVS item is scored on a 7-point scale ranging from 1 (fully dependent mobility) to 7 (normal independent mobility). COVS scores are generally reported as a single composite score ranging from 13 to 91. In an SCI population, 2 subscales have also been reported, of which the first is a general mobility score ranging from 7 to 49 and the second is an ambulation score ranging from 5 to 35. 7 As such, COVS offers a more relevant and more complete profile of mobility after SCI when compared with other mobility tools. A list of individual items and those that are included in the composite score and subscale scores is outlined in table 1. The findings of previous studies have shown that COVS has ac- ceptable construct validity when used in an SCI population, particularly when the 2 subscales are used. 7 It has been found to discriminate between respondents across lesion levels, com- pleteness of injury level, American Spinal Injury Association impairment grade and walking status at the individual item, composite score, and subscale score levels. In addition, COVS has been found to have acceptable internal consistency and inter- rater reliability between hospital and community settings and greater sensitivity than the FIM instrument in measuring changes over time for assessment of mobility in people with SCI. 8 From the Spinal Outreach Team (Barker, Amsters, Pershouse) and the Transitional Rehabilitation Program (Kendall), Queensland Spinal Cord Injuries Service, Princess Alexandra Hospital; and the University of Queensland and Princess Alexandra Hospital (Haines), Brisbane, Queensland, Australia. Supported by the Queensland Health and the Centre of National Research on Disability and Rehabilitation. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Kiley J. Pershouse, BSocWk, Spinal Outreach Team, PO Box 6053, Buranda, Queensland, 4102, Australia, e-mail: kiley_pershouse@health.qld.gov.au. 0003-9993/07/8805-11323$32.00/0 doi:10.1016/j.apmr.2007.02.032 632 Arch Phys Med Rehabil Vol 88, May 2007