Valuing condition specific health states using simulation contact lenses
C Czoski-Murray, J Carlton, JE Brazier, HK Kang, TA Young, NL Papo
OBJECTIVE:This article reports on a study that used contact lenses to simulate the effects of a visual impairment caused by age-related macular degeneration (ARMD). The primary objective was to examine the feasibility of using this method of simulation. A secondary objective was to compare the results from this experiment with those obtained from ARMD patients (n = 209) using generic preference-based measures (Health Utilities Index 3 (HUI3) and EUROQOL 5 Dimensions (EQ-5D) and patient time trade-off (TTO).
METHODS: Utility values were elicited from healthy participants (n = 108) for three ARMD states simulated using contact lenses.
RESULTS: A significant relationship was found between visual acuity and TTO values elicited from our sample population (n = 108). It was stronger than that found for HUI3, EQ-5D, and own TTO values from patients (n = 209). Our sample values informed by the experience of simulation were found to be significantly different from values from patient TTO and generic preference-based measures obtained from patients for the same level of visual impairment. Sociodemographic characteristics did not significantly affect results, although baseline TTO utility values were positively associated with TTO values for simulated states. Nevertheless, the patient population was significantly older than the sample population.
CONCLUSIONS: ARMD has a major impact on our sample values TTO health state values. Differences across four visual health severity groups appear larger than those found for a generic preference-based measure and patient TTO values. For conditions that are difficult to describe and imagine, simulation methods may offer an additional tool when combined with usual methods of description for obtaining better informed general population preferences.