Issues encountered when using health state utility values in decision analytic models

The publications used in this thesis consist of eight first author publications (2008 to 2013) exploring three technical issues that arise when using health state utility values (HSUVs) in decision analytic models in health care. The research provides analysts with HSUVs that may be used to describe the health-related quality of life (HRQoL) associated with not having particular conditions (i.e., the baseline evidence), recommendations on the preferred method to estimate HSUVs for comorbidities when the required evidence is not available, functions that can be used to map between two of the most commonly used HRQoL instruments (EQ-5D and SF-6D) using individual level patient data, and showed how well these functions estimate mean HSUVs from non-preference-based mean scores. The collection of work provides a unique and original contribution to the evidence base by bringing several previously overlooked issues into the public domain. This was an underdeveloped area of health economics and the lack of methodological guidelines in this area could result in sub-optimal allocation of scarce resources. This undermines the rationale behind the use of the quality adjusted life-year (QALY) and decision-making informed by cost per QALY thresholds. The publications received positive comments during the peer-review process and have been cited in approximately 280 journal articles. The condition-specific and general population HSUVs, and the mapping functions, have been used to inform the HSUVs used in 146 different decision analytic models. The mapping functions have also been used to predict HSUVs in an additional 37 articles. The remaining articles use the research to either support their choice of methods or to support or compare the results with their own results. The body of work has informed Technical Support Documents commissioned by the National Institute for Health and Care Excellence, a book chapter, methodological reports and training courses provided to the pharmaceutical industry, lectures on a post-graduate degree course, and an annual short-course at the University of Sheffield.