Analog scale, magnitude estimation, and person trade-off as measures of health utility: biases and their correction

Abstract

Subjects judged the disutility of health conditions "e[g[ blindness# using one of them "e[g[ blindness¦deafness# as a standard\ using three elicitation methods] analog scale "AS\ how bad is blindness compared to blindness¦deafness<#^mag! nitude estimation "ME\ blindness¦deafness is how many times as bad as blind! ness<#^and person trade!o} "PTO\ how many people cured of blindness is as good as 09 people cured of blindness¦deafness<#[ ME disutilities of the less bad condition were smallest\ and AS was highest[ Interleaving PTO with ME made PTO more like ME[ AS disutilities were inconsistent with direct judgments of di}erences between pairs of conditions[ ME and PTO judgments were internally inconsistent] e[g[ the disutility of one!eye!blindness relative to blindness¦deafness was larger than predicted from comparison of each to blindness[ Consistency training reduced inconsistency\ increased agreement between AS and PTO\ and transferred from one method to the other[ The results support the use of con! sistency checks in utility elicitation[

Revising a Priority List Based on Cost-Effectiveness

“…Subjects would then want to move them down. Baron and others 9 found that rating scale judgments yield smaller disutilities for health conditions and are more consistent with each other when subjects are first asked whether a condition is closer to one end of the scale or the other (normal health or death). For example, a subject who rates blindness as 40 on a scale from 0 (death) to 100 (normal) may revise this number upward after judging that blindness is closer to normal health than to death.…”

Revising a Priority List Based on Cost-Effectiveness

“…Subjects would then want to move them down. Baron and others 9 found that rating scale judgments yield smaller disutilities for health conditions and are more consistent with each other when subjects are first asked whether a condition is closer to one end of the scale or the other (normal health or death). For example, a subject who rates blindness as 40 on a scale from 0 (death) to 100 (normal) may revise this number upward after judging that blindness is closer to normal health than to death.…”

Lack of multiplicative transitivity in person trade‐off responses

“…Respondents were allowed to change previous numbers in their 10 PTO elicitations at any time in order to make them consistent. Moreover no difference was found between PTO numbers elicited by written format (n ¼ 26) and interview based format (n ¼ 22) [46].…”

The lack of theoretical support for using person trade-offs in QALY-type models

“…In a similar spirit, the World Health Organization has in some instances used a Disability-Adjusted Life Years (DALY) model with disability weights estimated by person trade-off protocols for assessment of region-and disease-specific burden of disease [50]. 1 Despite the popularity of health indices based on person trade-offs and many conceptual (non-technical) or experimental studies of the pros and cons of using such person trade-off based indices, theoretical support for its use has not been investigated ( [6,11,13,17]). In contrast, Williams [49] argues that the person trade-off method, as employed in the DALY valuations, muddles the valuation of the health states with people's views about distributional issues.…”

Revising a Priority List Based on Cost-Effectiveness

“…Subjects would then want to move them down. Baron and others 9 found that rating scale judgments yield smaller disutilities for health conditions and are more consistent with each other when subjects are first asked whether a condition is closer to one end of the scale or the other (normal health or death). For example, a subject who rates blindness as 40 on a scale from 0 (death) to 100 (normal) may revise this number upward after judging that blindness is closer to normal health than to death.…”

Lack of multiplicative transitivity in person trade‐off responses

“…Respondents were allowed to change previous numbers in their 10 PTO elicitations at any time in order to make them consistent. Moreover no difference was found between PTO numbers elicited by written format (n ¼ 26) and interview based format (n ¼ 22) [46].…”

The lack of theoretical support for using person trade-offs in QALY-type models

“…In a similar spirit, the World Health Organization has in some instances used a Disability-Adjusted Life Years (DALY) model with disability weights estimated by person trade-off protocols for assessment of region-and disease-specific burden of disease [50]. 1 Despite the popularity of health indices based on person trade-offs and many conceptual (non-technical) or experimental studies of the pros and cons of using such person trade-off based indices, theoretical support for its use has not been investigated ( [6,11,13,17]). In contrast, Williams [49] argues that the person trade-off method, as employed in the DALY valuations, muddles the valuation of the health states with people's views about distributional issues.…”

Revising a Priority List Based on Cost-Effectiveness

“…Subjects would then want to move them down. Baron and others 9 found that rating scale judgments yield smaller disutilities for health conditions and are more consistent with each other when subjects are first asked whether a condition is closer to one end of the scale or the other (normal health or death). For example, a subject who rates blindness as 40 on a scale from 0 (death) to 100 (normal) may revise this number upward after judging that blindness is closer to normal health than to death.…”

Lack of multiplicative transitivity in person trade‐off responses

“…Respondents were allowed to change previous numbers in their 10 PTO elicitations at any time in order to make them consistent. Moreover no difference was found between PTO numbers elicited by written format (n ¼ 26) and interview based format (n ¼ 22) [46].…”

The lack of theoretical support for using person trade-offs in QALY-type models

“…In a similar spirit, the World Health Organization has in some instances used a Disability-Adjusted Life Years (DALY) model with disability weights estimated by person trade-off protocols for assessment of region-and disease-specific burden of disease [50]. 1 Despite the popularity of health indices based on person trade-offs and many conceptual (non-technical) or experimental studies of the pros and cons of using such person trade-off based indices, theoretical support for its use has not been investigated ( [6,11,13,17]). In contrast, Williams [49] argues that the person trade-off method, as employed in the DALY valuations, muddles the valuation of the health states with people's views about distributional issues.…”