Focusing illusion, adaptation and EQ-5D health state descriptions: the difference between patients and public

Patients tend to assign higher utilities to health states compared with the general public. Several explanations have been given for this difference including focusing illusion -, caused in part by the sparseness of a health state description such as the EQ-5D -, and adaptation.

We investigated whether patients and the public differ in which dimensions they find important. Furthermore, we compared whether the dimensions named by patients and the public obtained higher rankings of importance compared with the predefined EQ-5D dimensions. Within each nominated dimension we investigated whether the public used a more negative frame compared with patients. In addition, adaptation was investigated by comparing patients with high levels of adaptation and patients with low levels of adaptation.

Data were collected using semistructured interviews among 124 patients with rheumatoid arthritis and 64 members of the public. Participants indicated which aspects are important to them when they think about their life having rheumatoid arthritis and rated the importance of these aspects and of the EQ-5D dimensions.

In contrast to patients, the public named more often aspects related to sports and mobility, leisure activities and work and framed these aspects negatively. Compared with self-rated dimensions, the public ranked the EQ-5D dimensions as more important whereas patients found both groups of aspects equally important. Patients who showed higher levels of adaptation did not differ significantly from patients with lower levels.

The public is focused on life domains that are negatively influenced by the described health state whereas patients are focused on both the positive and negative aspects of their lives.