Graphic representation of illness: a novel method of measuring patients' perceptions of the impact of illness.

BACKGROUND: Health outcome is multi-faceted, and for both research and clinical practice, greater knowledge of its facets is required. The Pictorial Representation of Illness and Self Measure (PRISM) was developed as a simple, rapid measure of the current impact of illness and symptoms on the individual.
METHODS: The PRISM task was completed by 26 outpatients with rheumatoid arthritis participating in a larger study of psychosocial correlates of arthritis, which included assessment of disease variables, functional impairment, pain, depression and patients' appraisals of their illness. In the PRISM task, the patient was asked to imagine that a small board represents his/her life and a fixed disk on the board represents his/her 'self'. The task was to place another (Illness) disk on the board to represent the current importance of illness in the patients' life. The main outcome measure was the distance between the Self and Illness disks.
FINDINGS: Only 2 patients had difficulty understanding the task. PRISM distance did not correlate with any disease variables. It correlated inversely with pain, functional impairment and depression, and positively with coping resources. PRISM distance correlated with perceived control over illness and negatively with awareness of illness.
INTERPRETATION: PRISM is an innovative measure, simple and well accepted by patients. It appears to measure what in German is termed leidensdruck, the burden of suffering due to illness. It offers a promising measure of an intangible but important health outcome, hitherto neglected, applicable to research interventions and clinical practice.