Excellent test-retest reliability for Oswestry Disability Index; variable levels of responsiveness
WEDNESDAY, July 11 (HealthDay News) -- For patients with lumbar spinal stenosis the Oswestry Disability Index, Modified Swiss Spinal Stenosis Scale (SSS), and Patient Specific Functional Scale have been shown to possess adequate psychometric properties for use in assessment of outcome, according to a study published online July 2 in The Spine Journal.
Joshua A. Cleland, P.T., Ph.D., from Franklin Pierce University in Concord, N.H., and colleagues conducted a secondary analysis of 55 patients (mean age, 69.5 years; 43.1 percent female) with lumbar spinal stenosis receiving outpatient physical therapy participating in a randomized clinical trial. The Oswestry Disability Index, SSS, Patient Specific Functional Scale, and Numeric Pain Rating Scale (NPRS) were completed at baseline and follow-up in order to assess test-retest reliability, responsiveness, and minimum levels of detectable and clinically important differences. To categorize whether patients experienced clinically meaningful change, a 15-point Global Rating of Change was conducted at follow-up.
The researchers found that the only outcome measure which showed excellent test-retest reliability was the Oswestry Disability Index, with an intraclass correlation coefficient of 0.86; all other measures ranged between fair and moderate. The Oswestry Disability Index, SSS, and Patient Specific Functional Scale showed varying levels of responsiveness but were superior to the NPRS. For the Oswestry Disability Index the minimal clinically important difference was five points.
"The results of our study indicate that the Oswestry Disability Index, SSS, and Patient Specific Functional Scale possess adequate psychometric properties to be used in the outcome assessment of patients with lumbar spinal stenosis," the authors conclude.
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