Interpreting pharmacoeconomic and quality-of-life clinical trial data for use in therapeutics

Interpretation of quality-of-life (QOL) and pharmacoeconomic data for therapeutic decision making and therapeutic policy planning requires a basic understanding of the methods, assumptions and limitations of the data and associated methods of analysis. Measures of the effectiveness of different pharmaceutical agents can be modified by including functions which involve assessment of the treated individual's quality of life. These quality-adjusted effectiveness measures will alter conclusions concerning clinical decisions as well as the cost-effectiveness of the comparative agents under consideration. To provide a conceptual and analytical framework for understanding the relationship between QOL assessment and pharmacoeconomic modelling, interpretations of the quality-adjusted analyses are reviewed, conceptual and analytical models are proposed, and recommendations for using QOL data in pharmacoeconomic models are outlined. Techniques for incorporating QOL measures in pharmacoeconomic models are examined using a hypothetical model involving therapeutic assessments of antiviral treatments for individuals with HIV disease. Adjustments of effectiveness measures based upon QOL-related functions are then globally addressed using stochastic compartmental models. Three specific methods for adjustment used in therapeutic trials are reviewed. Applications of these techniques to 3 studies involving the treatment of HIV disease and hypertension are critically reviewed. Issues relevant to choosing or estimating measures of quality of life for use in pharmacoeconomic models are summarised, and research guidelines are proposed.