FOCUSING ILLUSION AND EQ-5D HEALTH STATE DESCRIPTIONS: PATIENTS VS. PUBLIC

Purpose: Patients tend to assign higher utilities compared to the public. Several explanations are given for this difference of which focusing illusion, including the sparseness of a health state description such as the EQ-5D, and adaptation. Objective of the study was to investigate if patients and the public differ in which dimensions they find important. Further, we wished to assess whether patients and participants assigned higher rankings of importance to their self-nominated dimensions that to the predefined EQ-5D dimensions. Within each nominated dimension we investigated if the public used a more negative frame compared to patients. Similarly, adaptation was investigated by comparing patients with high levels of adaptation and patients with low levels of adaption.

Method: Data were collected using semi-structured interviews among 124 patients and 64 members of the public. Participants indicated which aspects were important to them when they think about their (imagined) life with Rheumatoid Arthritis and rated the importance of these aspects and of the EQ-5D dimensions.

Result: The public named more often aspects related to Sports & mobility (49% vs 27%), Leisure Activities (37% vs 23%), and Work (46% vs 26%), and framed these aspects more negatively (median framing value of the public = -0.75 vs. median of the patients = 0.00; Chi-Square(1) = 23.92, p < 0.005). The mean rank-order of EQ-5D dimensions was not different from the rank-order of self-named dimensions in patients (mean=3.47(1.24) vs. mean=3.26 (1.19); z = -1.64, p = .101). By contrast, members of the public rated the EQ-5D dimensions as more important compared to the self-named dimensions (mean=3.30 (0.99) vs. mean=4.01 (1.42); z = -3.32, p = .001). Patients who had higher adaptation level did not differ much from patients with lower adaptation.  

Conclusion: The public is focussed on life domains that are negatively influenced by having a health state, whereas patients are focussed on life more in general. Patients’ picture of a health state might better reflect reality.