Answer: The COPM is designed as an outcome measure and consequently, the scores are used for comparative purposes at reassessment. Unlike some norm-referenced tests where you compare your client’s score against a population norm, the COPM is an individualized measure, so the client’s scores are compared against their own reassessment scores. Our research has indicated that changes of two or more points on the COPM are clinically important.
Adding the scores on each problem, then dividing by the number of problems, gives the average score for each domain. These scores provide a summary and may be of interest to you and your clients. More typically, they would be useful in program evaluation, quality improvement, and research activities where the interest may be on more summative measures of change. Two cautions are important in interpreting the average scores. There may be times when therapy goals will indicate that performance or satisfaction decreases over a period of time (e.g., an increased level of insight may cause clients to rate themselves lower for an activity on the reassessment). Adding negative change and positive change may be misleading. You may want to consider the two separately. A second concern arises when adding scores across areas of occupational performance. The types of problems identified may vary in complexity (e.g., tying one’s shoes versus finding a new job). It may not be very meaningful to add scores across a variety of problems, as much of the meaning will be lost. Looking for increases/decreases between Time 1 and Time 2 assessments for each problem provides more relevant information.