Measuring health status with the Dartmouth COOP charts in low-functioning elderly. Do the illustrations affect the outcomes?

The Dartmouth COOP method consists of seven questions measuring seven domains of health status: physical fitness, feelings, daily activities, social activities, change in health status, current overall health perceptions and bodily pain. Each question has five response options and each option is accompanied by an illustration. In this paper, we present the results of a randomized study of the effects of the illustrations of the seven Dartmouth COOP charts in a low-functioning elderly sample. In addition, the subjective evaluation of the illustrations was examined. The results showed no significant differences between the outcomes obtained with the illustrated COOP charts and the unillustrated COOP charts: the mean scores, patterns of intercorrelations and associations with other measures for the research participants who filled in the illustrated COOP charts hardly differed from those obtained from the participants who filled in the unillustrated charts. Furthermore, the results showed that approximately three-quarters of the research participants considered the illustrations informative, while approximately 17% of the participants considered the pictures exaggerated. We conclude that, as long as there is no empirical support for the advantages of the COOP charts with respect to cross-cultural standardization or use in subjects who have, for example, difficulty in reading, there seems to be no need for the illustrated COOP charts. The results of our study showed that both types of COOP charts appear to be interchangeable.