Valuing condition specific health states using simulation contact lenses

OBJECTIVE: This paper reports on a study that used contact lenses to simulate the effects of a visual impairment caused by Age Related Macular Degeneration (ARMD). The aim was to examine the feasibility of using this method of simulation and to compare the results from this experiment with those obtained from ARMD patients (n=209) using generic preference-based measures (HUI3 and EQ-5D) and patient time trade-off TTO.

METHODS: Utility values were elicited from healthy participants (n=108) by TTO for three ARMD states simulated using contact lenses.

RESULTS: A significant relationship was found between visual acuity and TTO values elicited from members of the general population (n=108). It was stronger than that found for HUI3, EQ-5D and own TTO values from patients (n=209). General population values informed by the experience of simulation were found to be significantly different to values from patient TTO and generic preference-based measures for the same level of visual impairment. Socio-demographic characteristics did not significantly affect results, although baseline TTO utility values were positively associated with TTO values for simulated states.

CONCLUSIONS: ARMD has a major impact on general population TTO health state values. Differences across four visual health states appear larger than those found for a generic preference-based measures and patient TTO values. For conditions that are difficult to describe and imagine, simulation methods may offer an important method for obtaining better informed general population preferences.