Project Activities
The research was conducted in four phases. In phase 1, the researchers examined item hierarchy and dimensionality in the SOM™ using an existing dataset of elementary and high school students. In phases 2 and 3, therapists collected baseline and follow-up data on the revised SOM™ and the Pediatric Evaluation of Disability Inventory–Computer Adaptive Test (PEDI-CAT) to establish the validity and responsiveness of the SOM™. In phase 4, an open access online data collection system was developed.
Structured Abstract
Setting
Data collection took place in preschools and elementary, middle, and high schools in five large school districts in New York, Illinois, Pennsylvania, Oklahoma, and New Mexico. Data were also collected from independent occupational and physical therapists across the U.S.
Sample
Participants included 248 school-based occupational and physical therapists from across the U.S. Each therapist recruited and collected SOM™ data from students on their caseloads (students receiving OT and/or PT as designated by their Individual Education Program; IEP), totaling 857 students ages 3 to 21. An additional 248 students were included in the national Beta testing.
The SOM™ is a 51-item measure that is completed by related services providers using the web-based data collection system. The SOM™ quantifies physical and behavioral functional abilities of students with disabilities who receive school-based OT and/or PT related services, with items that assess students' level of independence in fulfilling tasks and roles in school that are necessary for participation in learning. The SOM™ is a context-specific measure that assesses how all individuals perform in a given setting regardless of age or type of disability. The measure also includes items related to student and therapist demographics, student IEP (such as, disability category, educational placement, and frequency of therapy), therapy activities, and services provided.
Research design and methods
Research activities occurred in four interrelated phases. In phase 1, the researchers used existing data from elementary and high school students to examine the item hierarchy and dimensionality of the measure and revise the SOM™ so that it is appropriate for all age groups of students. During phase 2, baseline data on the revised SOM™ and the PEDI-CAT was collected from a national sample of students (stratified by age group and disability severity). Researchers re-examined the item hierarchy and dimensionality of the SOM™ for each severity level and age group. In phase 3, follow-up data on the SOM™ and PEDI-CAT was collected 4.5 and 10 months after baseline. In conjunction with an anchor-based Rasch analysis approach, the PEDI-CAT was used as a reference standard to determine the responsiveness of the SOM™ and the change scores representing the MFSD (amount of change that must be achieved to reflect a true difference in pre/post intervention scores beyond measurement error). Phase 4 involved the development of an open access data collection system that therapists can use to collect SOM™ data nationwide and measure the effectiveness of their services.
Control condition
Due to the nature of the research design, there was no control condition.
Key measures
In addition to the SOM™, the PEDI-CAT was used to assess the construct validity of the SOM™. The PEDI-CAT is a comprehensive measure that assesses functional skills, including daily activities in the home and community, of children in infancy through age 20.
Data analytic strategy
The primary data analytic approach included unidimensional and multidimensional Rasch rating scale and partial credit models. In phases 1 and 2, Rasch analysis was performed to examine internal consistency, dimensionality, rating scale functioning, and adherence to Rasch model requirements. In phases 3 and 4, the researchers conducted Rasch analysis and t-tests and computed a responsiveness coefficient (Guyatt Responsiveness Index for Responsiveness) to determine validity and responsiveness of the SOM™. Researchers determined the measure's MFSD by comparing SOM™ scores to the established PEDI-CAT cutoff scores.
Key outcomes
The main findings of this project, as reported by the principal investigator, are as follows:
- The SOM™ was successfully developed in REDCap, validated, and used by therapist participants in national student data collection and Beta testing.
- The items on the SOM™ were transposed to interval level items, with equal weight, and include both easy and hard items for students of all ages with all levels of (dis)abilities.
- The Rasch analysis revealed that the SOM™ is a multidimensional tool (5 dimensions/domains), meaning that each domain can stand alone vs. using the tool as a total sum scale. Thus, a minimal functional significant difference (MFSD) exists for each domain, providing to therapists (and students/families) the smallest change in an outcome (school functional dimension) required that a student would perceive as a meaningful change.
- The SOM™ is an open access national data system that collects longitudinal student data available to all practicing school-based occupational therapists and physical therapists.
People and institutions involved
IES program contact(s)
Project contributors
Products and publications
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ERIC Citations: Find available citations in ERIC for this award here.
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