In search of the evidentiary foundation of published Canadian economic evaluations (2001–06)

OBJECTIVES: The aim of this study was to present a review of economic evaluations conducted from a Canadian perspective and to characterize sources of evidence and statistical methods to analyze effectiveness measures, resource utilization, and uncertainty. METHODS: A search strategy was developed to identify Canadian economic evaluations published between January 2001 and June 2006. A standardized abstraction form was used to extract key data (e.g., study design, data sources, statistical methods). RESULTS: A total of 153 unique studies were included for review, of which 75 were evaluations of drug therapies and less than half were funded by industry. Cost-effectiveness analysis was the most common type of economic evaluation and 80 percent of the studies used modeling techniques. A single source of evidence for effectiveness measures was used in half of the studies. Statistical methods were commonly reported to compare effectiveness measures when the economic evaluation was conducted alongside a clinical trial but less commonly when determining effectiveness input parameters in model-based economic evaluations, or to analyze resource utilization data. Authors relied mostly on univariate sensitivity analyses to explore uncertainty. CONCLUSIONS: This review identifies the need to improve the conduct and reporting of statistical methods for economic evaluations to improve confidence in the results.