Economic evaluations are used to inform decision makers about the efficient allocation of scarce healthcare resources and are generated with the direct intent to support decisions in healthcare. Producing guidelines is a complex process and the inclusion of health-economic aspects in the formulation of the Swedish national guidelines as a basis for the written recommendations (priority gradings), distinguishes them from their European counterparts. Despite the increased use of cost-effectiveness data in decision-making, little is known about the actual use of such data. This thesis covers issues concerning how economic evaluations matter in health policy decision-making. The thesis includes four papers based on the Swedish national guidelines for heart diseases, one of the most prominent examples in Sweden of following the notion of evidence-based policy (EBP), in order to inform explicit priority setting.

Both Papers I and II followed a qualitative case study design, based on the same data set. Paper I explored how a specific working group, the Priority Setting Group (PSG), handled the various forms of evidence and values when producing the national guidelines. Two themes were identified in reaching collective agreement in priority gradings; group facilitation activities and avoiding deadlock in the discussion. The work process involved disagreement and negotiation as part of that task. Paper I contributes to the theoretical and practical debate on EBP. Paper II focused on the use of cost-effectiveness data as decision support in the PSG work process. The paper addressed availability of cost-effectiveness data, evidence understanding, interpretation difficulties, and the reliance on evidence. Three themes were identified. The paper contributes to knowledge on how cost-effectiveness evidence was used in actual decision-making. The use of cost-effectiveness evidence was one of many tools employed to avoid deadlock in discussion and to reach a priority grading, when the overall evidence base was weak, in times of uncertainty and on the introduction of new expensive medical technologies.

Quantitative research methods were used for both Papers III and IV. Paper III explored how the PSG was presented with cost-effectiveness evidence as decision support and as a basis for their priority gradings. Cost-effectiveness ratios (ICERs) were provided, based on a  systematic literature review, as well as how the results may be conveyed and communicated, for the treatment of heart diseases using a cost-effectiveness ranking or league and providing valid information within a limited space, aiding decision makers on the allocation of healthcare resources. The thesis also includes decision support in the form of cost-effectiveness analysis on catheter ablation treatment. Paper IV provides an example of presenting evidence in the form of a decision-analytic model. The modelling approach provides an analytic framework for decision-making, specifically under conditions of uncertainty as in the introduction of new medical technology. Catheter ablation was associated with reduced cost and an incremental gain in quality adjusted life years (QALYs), and was considered a cost-effective treatment strategy compared to the medical treatment strategy in a lifetime perspective.