Health economics is the study of how scarce healthcare resources are used and should be used. Because resources are scarce, healthcare decision makers must decide, given the available evidence, how to deploy resources in a manner that optimizes value for money. The use of health economic tools aid decision makers in their deployment strategies by: clearly identifying the relevant alternatives, transparently evaluating the perspectives and inputs of the strategies, and modeling uncertainty and what if scenarios (1). Health economics is important because of the desire to make the decision process and its outcomes, more rational and transparent. This desire is revealed through the emergence of government and regional health bodies such as the National Institute for Health & Clinical Excellence (NICE), Scottish Medicines Commission (SMC), Medical Products Agency, Canadian Agency for Drugs and Technologies in Health (CADTH), and Pharmaceutical Benefits Advisory Committee (PBAC). These agencies use health economics to help inform the technology coverage decisions of England and Wales, Scotland, Sweden, Canada, and Australia, respectively.
Previous reviews have summarized the literature on the economic evaluations of asthma interventions (2–8). Sullivan and Weiss observed that the literature was evolving, but did not meet the standards of the time (4). They commented that amongst the studies reviewed, time horizons were not long enough and relevant comparators were not always used. They also argued that there was a lack of standardized outcomes in asthma economic evaluations. Sculpher and Price in their review that extended to 2002 remarked on many of the same issues and made suggestions for overcoming the common weaknesses observed in the literature (3). They advocated for longer term pragmatic trials, explicit statement of the perspective, and the use of cost-consequence models. They noted that only two of the 33 studies reviewed at that time reported utilities and suggested the increased use of generic measures alongside disease specific measures. Lee and Weiss added in their one year update that pharmaceutical agents are the primary component of direct medical expenditures and stressed the importance of evaluating the costs and outcomes of pharmaceuticals and their alternatives (2). Feenstra et al. compared the cost-effectiveness literature for children with asthma to four different asthma guideline bodies (5). They concluded that although cost-effectiveness was not explicitly included in the guidance, cost-effectiveness evidence was consistent with current treatment advice. Akazawa and Stempel (6), Shih et al. (7), and Shepherd et al. (8) reviewed the cost-effectiveness evidence of single inhaler combination therapy for persistent asthma.
We acknowledge the publication of previous asthma burden reviews. These reviews did not focus on the incremental benefit of asthma interventions, but rather focused on geographic specific burden (9, 10), pediatric burden (11–14) or work-related burden (15).
The aim of this systematic review was to summarize and assess the quality of asthma intervention health economic studies from 2002 to 2007, compare the study findings with clinical management guidelines, and suggest avenues for future improvement of asthma health economic studies. No outside funding was provided for the conduct of this study.