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.
BaronK.KielhofnerG.IyengerA.GoldhammerV., & WolenskiJ. (2006). The Occupational Self Assessment (OSA) (Version 2.2). Chicago: Model of Human Occupation Clearinghouse, Department of Occupational Therapy, College of Applied Health Sciences, University of Illinois at Chicago.
2.
BaumC., & EdwardsD. (2001). The Washington University Activity Card Sort. St. Louis, MO: Penultimate Publications.
3.
BeckermanH.RoebroeckM. E.LankhorstG. J.BecherJ. G.BezemerP. D., & VerbeekA. L. (2001). Smallest real difference, a link between reproducibility and responsiveness. Quality of Life Research, 10, 571–578.
4.
BensonJ., & SchellB. A. (1997). Measurement theory: Application to occupational and physical therapy. In Van DeusenJ. & BruntD. (Eds.), Assessment in occupational therapy and physical therapy (pp. 3–24). Philadelphia: W. B. Saunders.
5.
CronbachL. J. (1990). Essentials of psychological testing (5th ed.). New York: Harper and Row.
6.
KielhofnerG. (2008). A model of human occupation: Theory and application (4th ed.). Baltimore: Lippincott, Williams & Wilkins.
7.
KielhofnerG.DobriaL.ForsythK., & BasuS. (2005). The construction of keyforms for obtaining instantaneous measures from the Occupational Performance History Interview rating scales. OTJR: Occupation, Participation & Health, 25, 23–32.
8.
KielhofnerG., & ForsythK. (2001). Measurement properties of a client self-report for treatment planning and documenting therapy outcomes. Scandinavian Journal of Occupational Therapy, 8(3), 131–139.
9.
KielhofnerG.ForsythK.KramerJ., & IyengerA. (in press). Developing the Occupational Self Assessment: The use of Rasch analysis to assure internal validity, sensitivity, and reliability. British Journal of Occupational Therapy.
10.
KielhofnerG., & NevilleA. (1983). The modified interest checklist. Unpublished manuscript, Model of Human Occupation Clearinghouse, Department of Occupational Therapy, University of Illinois at Chicago.
11.
LawM.BaptisteS.CarswellA.McCollM. A.PolatajkoH., & PollockN. (2005). The Canadian Occupational Performance Measure (4th ed.). Ottawa, Ontario, Canada: CAOT Publications.
12.
LeeS. W.TaylorR. R.KielhofnerG., & FisherG. (2008). Theory use in practice: A national survey of therapists who use the Model of Human Occupation. American Journal of Occupational Therapy, 62, 106–117.
13.
LexellJ. E., & DownhamD. Y. (2005). How to assess the reliability of measurements in rehabilitation. American Journal of Physical Medicine and Rehabilitation, 84, 719–723.
14.
LinacreJ. M. (1997). Instantaneous measurement and diagnosis: Paper presented at the First International Outcome Measurement Conference. Physical Medicine & Rehabilitation, 11, 315–324.
15.
National Board for Certification in Occupational Therapy, Inc. (2004). A practice analysis of entry-level occupational therapist registered and certified occupational therapy assistant practice. OTJR: Occupation, Participation, & Health, 24(suppl. 1), S1–S31.
16.
OakleyF.KielhofnerG., & BarrisR. (1985). An occupational therapy approach to assessing psychiatric patients' adaptive functioning. American Journal of Occupational Therapy, 39, 147–154.
17.
SchwartzC. E.AndresenE. M.NosekM. A.KrahnG. L., & the RRTC Expert Panel on Health Status Measurement. (2007). Response shift theory: Important implications for measuring quality of life in people with disability. Archives of Physical Medicine and Rehabilitation, 88, 529–536.
18.
ShroutP. E., & FleissJ. L. (1979). Intraclass correlations: Uses in assessing rater reliability. Psychological Bulletin, 86, 420–428.
19.
TurcotK.AissaouiR.BoivinK.HagemeisterN.PelletierM., & de GuiseJ. A. (2008). Test-retest reliability and minimal clinical change determination for 3-dimensional tibial and femoral accelerations during treadmill walking in knee osteoarthritis patients. Archives of Physical Medicine and Rehabilitation, 89, 732–737.
20.
WolfeE. W., & ChiuC. W. T. (1999). Measuring change across multiple occasions using the Rasch Rating Scale Model. Journal of Outcome Measurement, 3, 360–381.
21.
WrightB. D., & MastersG. N. (1982). Rating scale analysis. Chicago: MESA Press.
