The Occupational Self Assessment: Stability and the Ability to Detect Change Over Time

Headnote

key words: Model of Human Occupation, Rasch rating scale model

ABSTRACT

The Occupational Self Assessment (OSA) was designed to guide collaborative treatment planning and measure client-reported change to document therapy outcomes. This study examined the stability of the OSA and its ability to detect changes in reported Competence and Values. The OSA was administered twice to 112 participants with disabilities 58 to 650 days apart. A Rasch rating scale model was used to analyze the data and determine the stability. Competence and Values items were stable over time. The Competence rating scale was used by participants in the same manner at both administrations. However, the Values rating scale was used differently at time 2; participants were less likely to use the Values rating scale category "More important" at time 2. Thirty-two percent and 49% of participants had significantly different measures at time 2 on Competence and Values scales, respectively. This study lends support for the use of the OSA as a client-reported outcome measure.

(ProQuest: ... denotes formulae omitted.)

Although occupational therapists have several self-report assessments of participation available for use in practice (Baron, Kielhofner, Iyenger, Goldhammer, & Wolenski, 2006; Baum & Edwards, 2001; Kielhofner & Neville, 1983; Law et al., 2005; Oakley, Kielhofner, & Barris, 1985), self-report assessments are infrequently used to evaluate the outcomes of occupational therapy intervention (Lee, Taylor, Kielhofner, & Fisher, 2008; National Board for the Certification in Occupational Therapy, Inc., 2004). One of the barriers to use of self-reports for documenting outcomes is concern about the dependability (reliability and validity) and sensitivity (ability to detect change) of such assessments. Practitioners may be more likely to use a self-report to evaluate outcomes if evidence confirmed the psychometric soundness of the assessment along with the ability of the assessment to capture change. Previous research has contributed evidence about the reliability and validity of the Occupational Self Assessment (OSA) (Kielhofner & Forsyth, 2001; Kielhofner, Forsyth, Kramer, & Iyenger, in press). The aim of this study was to generate further evidence concerning the stability of the OSA and its ability to detect change because both of these factors are crucial to determining the usefulness of the OSA as an outcome measure.

Background

The OSA was designed to guide collaborative treatment planning and measure...