The health state preferences and logistical inconsistencies of New Zealanders: a tale of two tariffs

Notwithstanding the proposed use of Cost-Utility Analysis (CUA) to inform health care priority setting in New Zealand, to date there has been no research into New Zealanders’ valuations of health-related quality of life. This paper reports the results of a study of the health state preferences of adult New Zealanders generated from a postal survey to which 1360 people responded (a 50% response rate). The survey employed a self-completed questionnaire in which a selection of health states were described using the EQ-5D health state classification system and respondents’ valuations were sought using a visual analogue scale (VAS). Close attention is paid to the quality of the data, in particular to the ‘logical inconsistencies’ in respondents’ valuations. Regression analysis is used to interpolate values over the 245 possible EQ-5D states. Two tariffs of health state preferences, arising from contrasting treatments of the logical inconsistencies, are reported.