A comparison of health state utilities for dentofacial deformity as derived from patients and members of the general public

The cost-utility approach is a method of economic evaluation, which assigns a ratio of cost to benefit, based on utility values of the health state in question. It allows efficient use of health care resources and is a useful method in that it permits comparison of a wide range of medical interventions, including those which are life saving and those that improve quality of life. This study obtained utility values for dentofacial deformity from orthognathic patients and members of the general public using three recognized methods--rating scale (RS), standard gamble (SG), and time trade-off (TTO). There were no significant differences between the utility values for the two groups of respondents. Method agreement between the TTO and the SG (the 'gold standard') was better than that between the RS and SG. In addition, the SG and TTO were found to have greater repeatability than the RS.