Researchers from several universities across the United States have developed and tested the Activity-based Balance Level Evaluation (ABLE), a new balance assessment tool for individuals with spinal cord injury (SCI). The study they performed was intended to develop a scale capturing the wide spectrum of functional ability following SCI and assess the initial psychometric properties of the scale using a Rasch analysis. The results were published in the August 2012 issue of Physical Therapy.
Elizabeth M. Ardolino, PT, PhD, from the department of physical therapy at the University of St. Augustine, Austin, TX, and her team used a methodological research design to test the initial psychometric properties of the ABLE scale, which is based on the Delphi technique. SCI individuals at each of four centers were evaluated using the ABLE scale, and a Rasch analysis was conducted to test for targeting, item difficulty, item bias, and unidimensionality. The researchers also completed an analysis of variance to test for discriminant validity.
According to the results, the Rasch analysis revealed a scale with minimal floor and ceiling effects as well as a wide range of item difficulty capturing the large scope of functional capacity after SCI. The researchers reportedly observed multiple redundancies of item difficulty. All raters of the study were physical therapists, which might have skewed the results, and the sample size of 104 participants precluded a principal component analysis.
The researchers conclude that development of an all-inclusive clinical instrument assessing balance in the SCI population was accomplished using the Delphi technique. In addition, modifications of the ABLE scale based on the Rasch analysis yielded a 28-item scale with minimal floor or ceiling effects. The authors write that larger studies using the revised scale and factor analyses are needed to establish unidimensionality and reduction of the total item number.
Source: Physical Therapy
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