From the perspective of a health system as a drug purchaser, it is becoming increasingly obvious that the traditional pharmacoeconomic cost-outcomes techniques of comparator drug evaluation are of limited application. The reason is that such approaches fail to address the information needs of drug purchasers. The key question that these evaluations should address is: If a new product is introduced to formularly, what will be the net impact on the costs of treatment of that disease or therapy area and on the outcomes profile of the treating population? It is on these criteria that claims made for lipid therapies should be judged. Issues that the traditional approach fails to address include: 1) the impact of budget constraints, 2) the determinants and impact of therapy switching, 3) the impact of poor compliance on claims for cost-effectiveness, and 4) the way in which more integrative approaches to treatment delivery might reinforce claims made for particular products. Guidelines are important in this process because they set out the informational requirements and analytical standards required of drug manufacturers making a submission to pharmacy and therapeutics committees. This paper identifies what may be considered to be the minimum informational requirements and suggests how a systems approach to drug evaluation could apply in the area of lipid therapy and the claims for competing products.