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 .
A cost-utility analysis of laser-assisted angioplasty for peripheral arterial occlusions.
Despite the perception of many people that lasers represent the cutting edge of high-technology medicine , this form of medical technology has been subject to relatively little rigorous evaluation . This dearth of research relates particularly to economic evaluation , where there have been few attempts to justify the high cost of laser equipment . This paper details an economic evaluation of the use of laser technology as a secondary adjunct to angioplasty to treat peripheral arterial occlusions . Using data from a range of sources , including a published r and omized trial , a cost-utility model is developed to estimate the costs and benefits of the laser , relative to st and ard angioplasty . The best available data indicate a cost-effective role for the laser , but important areas of uncertainty exist , including the  laser 's secondary recanalization rate , which has been estimated on the basis of limited numbers of patients . This uncertainty suggests that further research is required before widespread diffusion of the laser for use in this clinical context
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 .