The results of this study do not support the common view that RS values are lower than TTO values , may suggest that TTO biases largely cancel , and support the validity of formulas for correcting SG bias
Background .
A common assertion is that rating scale ( RS ) values are lower than both st and ard gamble ( SG ) and time tradeoff ( TTO ) values .
However , differences among these methods may be due to method specific bias .
Although SG and TTOs suffer systematic bias , RS responses are known to depend on the range and frequency of other health states being evaluated .
Over many diverse studies this effect is predicted to diminish .
Thus , a systematic review and data synthesis of RS-TTO and RS-SG difference scores may better reveal persistent dissimilarities .
The purpose of this study was to establish through systematic review and meta- analysis the net effect of biases that endure over many studies of utilities .
Relationship between health utility and psychometric health status measures.
This study examined the relationship between health utility and psychometric health status measures . Utility scores derived by st and ard gamble and categorical rating methods were also compared to determine if they produce equivalent preference scales . Health status and utility was assessed in 73 chronic renal disease patients with anemia ( hematocrit less than or equal to 30 ) participating in a 48-week clinical study .  Patient preferences for current health and three hypothetical states were assessed using st and ard gamble and categorical rating procedures . St and ard gamble utility was related to home management ( P less than .05 ) ; categorical rating utility was related to home management ( P less than .05 ) , energy ( P less than .05 ) , alertness behavior ( P less than .05 ) , social interaction ( P less than .05 ) , and life satisfaction scale scores ( P less than .05 ) . Only 25 - 27 % of the variance in utility scores was explained by the health status measures . St and ard gamble utilities were consistently higher than categorical rating values for end-stage renal disease with hemodialysis ( P less than .0001 ) and severe anemia requiring blood transfusions ( P less than .0001 ) . Patient preferences for current health may be influenced in part by their functional status and well-being , risk aversion or risk-taking attitudes , and the cognitive evaluation processes involved in making judgments necessary for the measurement task , as well as their actual preferences
The results of this study do not support the common view that RS values are lower than TTO values , may suggest that TTO biases largely cancel , and support the validity of formulas for correcting SG bias
Background .
A common assertion is that rating scale ( RS ) values are lower than both st and ard gamble ( SG ) and time tradeoff ( TTO ) values .
However , differences among these methods may be due to method specific bias .
Although SG and TTOs suffer systematic bias , RS responses are known to depend on the range and frequency of other health states being evaluated .
Over many diverse studies this effect is predicted to diminish .
Thus , a systematic review and data synthesis of RS-TTO and RS-SG difference scores may better reveal persistent dissimilarities .
The purpose of this study was to establish through systematic review and meta- analysis the net effect of biases that endure over many studies of utilities .