This review does not go in to details of the methods of valuation, which include TTO, standard gamble, visual analogue scale, discrete choice experiments (DCEs), and person trade-off.
He said: "The ability to tweak activity in parts of the brain, turning it slightly 'up' or 'down' at will, opens the door to treating a range of psychiatric and neurological problems, like compulsive gambling or visual impairments following stroke".
The three most commonly used approaches for direct assessment of utility are the time trade-off (TTO), standard-gamble, and visual analog scale (also referred to as rating scale) techniques [ 21].
Examples of indirect HU instruments include the Health Utilities Index, Mark3 (HUI3) and the Health Utilities Index, Mark2 (HUI2) [ 3], developed using direct HU measures from the standard gamble and visual analog scale (VAS) techniques and the EuroQOL 5-dimensions (EQ-5D) [ 4], developed using direct HU measures from time trade-off and VAS techniques.
The objective of this study was to compare discriminatory power of two different measures graphic positioning scale (GPS) versus traditional scale (TS in assessing respondent acceptability of three preference measures: visual analog scale (VAS), standard gamble (SG), and willingness to pay (WTP).
The utility values used in our study are derived from a study on quality of life in patients enrolled in SHCS [32] by transforming health state values assessed on a visual analogue scale into standard gamble utilities using methods as described in detail elsewhere [33].
Visual Analogue Scale and standard gamble techniques were used to measure utilities.
Highest scores were found for the patients' own current health state (Visual Analogue Scale: 0.77; standard gamble: 0.97).
Lowest scores were elicited for the health state 'irresectable tumour' (Visual Analogue Scale: 0.13; standard gamble: 0.34).
The SF-6D and HUI3 were valued using a visual analogue scale and standard gamble; the WHOQOL-BREF does not have preference based scoring.
