Preference for implant treatment - Standard gamble and time trade-off

Abstract

Standard gamble (SG) and time trade-off (TTO) are preference-based instruments to measure health-state utilities. Objectives: This study determined the utility values of dental implant treatment using SG and modified TTO. Methods: 59 adult Chinese subjects (18 males, 41 females, mean age=39) attending a University Dental Hospital were recruited. Conventional (fixed and removable partial dentures) and implant replacement options were described. Subjects were asked to imagine having missing anterior/posterior tooth scenarios. They were then asked to indicate the preferred option if the chance of success of an implant was X%, where X was randomly selected from 0-100. Using the bidding method at 10% increment (conventional option preferred) or decrement (implant preferred), value of SG was recorded at the final bid before the subjects chose the opposite option. Similarly, subjects were asked to bid the minimum years of service of implant replacement they could accept before they were left with no further replacement, with a starting bid of ten years and at 1 year increment/decrement. TTO was recorded when the subjects refused to accept or it exceeded/matched the subjects expected life expectancy. Demographic data regarding age, gender, education attainment, level of income, presence of missing teeth and restorative need were also collected. SG and TTO were compared between scenarios and among various demographic parameters. Results: SG values were 0.8 and 0.85 for anterior and posterior scenarios respectively (P > 0.05). Subjects with self-perceived ‘good’ dental health had SG values significantly lower than those with ‘fair’/’poor’ dental health (0.55 vs. 0.84/0.81, (P < 0.05). TTO for both scenarios was 13.67 years, with no difference between scenarios and among demographic parameters (P > 0.05). Conclusion: Subjects in this study could accept 20% risk of failure and a minimum of 13.67 years of service when considering implant treatment for tooth replacement.