Functional outcome in rheumatoid arthritis.

The ability to carry out daily activities depends on an individual's physical and psychological make up, and the environment and society in which he or she lives. Thus, rheumatoid arthritis produces functional impairment that is not simply related to the severity of the disease process. Two-thirds of patients are concerned more with potential loss of function than with discomfort. There is, therefore, a need to assess disability separately from inflammatory activity. The principles of disability measurement concern assessment of performance of everyday activities. Global measures or the performance of one or more specific activities can be used to assess aspects of mobility and manual dexterity. Activities can be related to social life and employment and can include assessment of psychological as well as physical disability. Many different tools are available and can be divided into: 1. Measures depending on clinical judgement. 2. Measures based on observed patient performance. 3. Measures depending on patients' opinions. In addition, a variety of health status measures have been described that include disability as one of a number of parameters aimed to assess the overall impact of the disease on the patient. Evaluation of these tools has been patchy. Full assessment using measurement theory (validity, simplicity, reliability and sensitivity) has not been undertaken for any index. However, the Health Assessment Questionnaire (HAQ) Disability Index and the Arthritis Impact Measurement Scales (AIMS) have both been tested fairly extensively in North America. The choice of a particular measurement tool depends on: 1. The context in which it will be used.(ABSTRACT TRUNCATED AT 250 WORDS)