Item test-retest reliability and responsiveness of the School Outcomes Measure (SOM)

The School Outcomes Measure (SOM) is a minimal data set designed to measure outcomes of students who receive school-based occupational therapy and physical therapy. The purpose of this study was to determine item test-retest reliability and the responsiveness to change of the SOM. Thirty-two occupational therapists and physical therapists collected data on 73 students, age 3-21 years, stratified into two groups based on the Gross Motor Function Classification System: those with mild/moderate functional limitations (Levels I, II, III) and those with severe functional limitations (Levels IV, V). Weighted kappa statistics (0.68-1.0) indicate good to excellent item test-retest reliability. Repeated measures analysis of variance indicated that the SOM is responsive to change in children with mild/moderate functional limitations but is less responsive to change in children with severe functional limitations. The findings support the use of the SOM to measure outcomes for students with mild/moderate functional limitations as well as enabling program evaluation of therapy services provided in school settings. More research is needed to evaluate responsiveness in students with severe functional limitations.