Pictorial Representation of Self and Illness Measure (PRISM): A Graphic Instrument to Assess Suffering in Fatigued Cancer Survivors

The Pictorial Representation of Self and Illness Measure (PRISM) measures in a simple, graphic way the burden of suffering due to illness. The question addressed in this study is whether the PRISM is a valid instrument to measure suffering in cancer survivors experiencing severe fatigue. Quantitative and qualitative data of a previous randomized controlled trial demonstrating the efficacy of cognitive behavior therapy (CBT) especially designed for postcancer fatigue was used to assess convergent validity and sensitivity to change in a sample of 83 cancer survivors. The PRISM, yielding self-illness separation (SIS-fatigue = suffering due to fatigue; SIS-cancer = suffering due to cancer), fatigue severity (Checklist Individual Strength; CIS-fatigue), functional impairment, psychological well-being, quality of life, and coping with the experience of cancer (Impact of Event Scale; IES). Moderate significant correlations were found with the PRISM and the above-mentioned measures. On the basis of SIS scores, the sample was divided into two separate groups: cancer survivors who suffered more because of fatigue and cancer survivors who suffered more because they had cancer in the past. The two groups had different scores on CIS-fatigue and IES, in line with that aspect that caused them the most suffering. The qualitative data confirmed this finding. Participants in the CBT condition demonstrated a significant difference between SIS-fatigue at baseline versus 6 months later compared with those in the waiting list condition. No change of SIS-cancer was found. The PRISM seems to be a valuable tool in fatigue research and clinical practice.