Instrument Development in Occupational Therapy.

Instrument Development in Occupational Therapy

This book represents a collection of articles which report on the refinement of an interview instrument, Assessment of Occupational Function (AOF). It has previously appeared in an issue of a journal, Occupational Therapy in Mental Health. Based on an occupational therapy practice model, the AOF consists of an interview and rating form. The instrument is described as a screening tool designed to collect information on dynamic aspects of performance which influence function. The work presented in the book supports the use of the AOF as a standardized assessment tool for occupational therapists in mental health settings. Following carefully defined strategies, the articles examine validity issues using the first revised edition of the AOF. The culmination of the work presented in the text results in a second revision which appears in an appendix in one of the articles.

The commentary by Kielhofner and the article by Watts, Rollier and Schmidt place the effort of this instrument development team in historic context. As they explain, there continues to be a need for standardized evaluation tools which are consistent with the philosophy of occupational therapy and reflect the unique contribution of the profession to the overall rehabilitation process. The authors of the different articles recognize that this is an initial step and that more work on the second revision of the AOF with other populations is needed. The studies reported in this text analyzed data derived from the same 41 interviews with patients who have schizophrenia as their primary diagnosis.

The first article by Watts and her colleagues reports the results of two studies. The first study compares the first revision of the AOF with another interview instrument. Both instruments were designed by occupational therapists to obtain an understanding of factors which influence how patients function. The high agreement between the two instruments is hardly a surprise. Although different questions were asked, both interview instruments utilized the same practice model and the same operational definitions of variables. The fact that both interviews were administered and scored by the same graduate research assistant raises questions about the results since the researcher is not blind to the scores from the first interview. As a result, experimenter bias could contribute to the agreement between the two tools. The second study summarizes on feedback from clinicians regarding the two instruments. The feedback was positive but occupational therapists who had used the AOF felt practice was necessary for effective scoring.

The second article examines the content validity of the first revised version of the AOF by using occupational therapists considered experts in using the model of human occupation. Rollier et al. accepted 63.6% or better agreement on individual items to indicate content validity. Generally, the study supports the assumption that the interview questions would elicit information relevant to the model's components. The need to examine three items which did not meet criteria is clearly discussed.

Concurrent validity for the AOF (first revision) was examined in the third article. Utilizing data reported in the first article of the text, this study examines the relationship of the total score of AOF with the Global Assessment Scale (GAS). The potential influence of SES on how patients are rated raises a concern about potential bias which warrants further study.

The fourth article summarizes the previous work and discusses how changes were made to create the second revision of the AOF. The authors call on occupational therapists to use the new form of the interview and rating process and provide feedback which will assist in further developing the tool. The final article provides the reader with a case sample of how the AOF can be used and provides important information about how a patient functions.

The clinical usefulness of the second revision of the AOF will be limited to those occupational therapists who have a firm understanding in the "throughput phase" of the model of Human Occupation. For other rehabilitation specialists as well as occupational therapists who use other practice models, this text offers an opportunity to examine one aspect of instrument development. The strength of this collection of articles is as an illustration of the process. Watts and her colleagues examine the benefit and costs of each decision which other instrument developers will have to face.

Readers who use this book as an example of instrument development must approach the work with a critical eye and make their own decisions regarding acceptable levels for validity and reliability. An instrument's reliability and validity is achieved over time where support is accumulated from different studies. The acceptable levels used in the developmental stages of this work may not be appropriate when an instrument is ready for distribution.