Practical issues in conducting pharmacoeconomic studies.

Many difficulties are inherent to pharmacoeconomic studies. Because these studies are observational, there are many factors that cannot be controlled; for example, there are many variations across the country in the practice of any particular therapy. Therefore, designing a case report form that will match the source documents from various investigator sites is not easy. Issues arise in every activity such as choice of investigator site, data collection, data analysis, and interpretation of the results. These issues will be discussed, and an example of a pharmacoeconomic study conducted to evaluate the cost-effectiveness of patch testing in patients diagnosed with allergic contact dermatitis will be presented.