A model of health status for rheumatoid arthritis. A factor analysis of the Arthritis Impact Measurement Scales.

Health status is a key aspect of quality of life that may be addressed and affected by health care. The measurement of this construct requires the identification of unique and relevant components of health status that can be operationally defined by specific scales or scale groupings. We explored the components of health status that are operationalized by the Arthritis Impact Measurement Scales (AIMS). Prior testing has shown that the AIMS measures delineate at least 3 components of health status: Physical Function, Psychological Status, and Pain. This 3-component model, however, can be theoretically and empirically restrictive. Using AIMS responses from a rheumatoid arthritis (RA) patient population, our investigation, through factor analyses, identifies 5 components of health status in this chronic disease: Lower Extremity Function, Upper Extremity Function, Affect, Symptom, and Social Interaction. It is proposed that these intuitively reasonable and measurable components constitute the core of the health status construct for individuals with RA. These 5 components could also prove central to the assessment of health status in other rheumatic diseases. Future studies of health status in RA should include tested measures to assess these 5 components.