Medicine is a very important health resource in China. Although numerous efforts are paid to pre-marketed medicines, little is done to address practical problems in marketed medicines. The rational use and allocation of marketed medicines remain a major concern for decision-makers in China. It has been recognized that economic evaluation is an efficient tool for prioritizing the choice, and optimizing the use of medicines. This paper has explored the methods and principles for conducting economic evaluation of marketed medicines. Different strategies will be adopted for economic evidence for marketed medicines in terms of adequacy and sufficiency.However, a standard study pathway should be applied in economic evaluation of marketed medicines. Besides, the aspects for developing economic framework and the methods for reviewing existing economic evidence are also introduced in this paper, particularly, for marketed medicines within the same therapeutic group.
Objective To assess the effectiveness and safety of nine lipid-lowing agents in the national essential drug list (2000) and provide evidence for the adjustment and selection of essential drugs. Methods Based on principles of health technology assessment (HTA) and evidence-based medicine, we searched for all published clinical studies about these drugs from the following databases: MEDLINE (1966-2002.8), The Cochrane Library, EMBASE (1974-2002), CBMdisk (1979-2002.8) and VIP (1989-2002.8), the database of National Center for Adverse Drug Reaction(ADR) Monitoring of China and the database of WHO Uppsala drug monitoring center. Included studies were appraised, analyzed and compared for the reduction of triglyceride (TC) or low density lipoprotein (LDL-C), the prevention for the coronary events and the incidence of ADR. Results The results from comparative trials for lipid-lowing agents showed that the equivalent dose of statins for 25% reduction of LDL-C was atorvastatin 10 mg/d, simvastatin 20 mg/d, pravastatin 40mg/d, lovastatin 40 mg/d, cerivastatin 0.3 mg/d and fluvastatin 80 mg/d. It was difficult to compare fenofibrate with gemfibrozil, acipimox with statins or fibrates based on available data. The study on the primary and secondary prevention of cardiovascular events showed that pravastatin and lovastatin were effective in primary prevention, and long-term use could reduce the incidence of cardiovascular disease.Gemfibrozil could reduce the mortality from coronary heart disease (CHD) but the overall mortality was not changed. Pravastatin, simvastatin, atorvastatin, fluvastatin, gemfibrozil and fenofibrate had a confirmed effect in secondary prevention. Data from large-scale clinical trials and the reports from ADR monitoring center of England, America, Canada and Australia suggested that the statins which had rare ADR were safe and tolerated. Rhabdomyolysis was rare but had a serious adverse reaction associated with statins. The rate of fatal rhabdomyolysis related to cerivastatin was the highest among 6 statins. The safety of simvastatin, lovastatin and atorvastatin was lower than cerivastatin but higher than simvastatin and atorvastatin. The number of ADR reports of fenofibrate was fewer than that of gemfibrozil. Conclusions At present, the best evidence focused on pravastatin, simvastatin and lovastatin are widely used and have a confirmed safety and efficacy. Atorvastatin, fluvastatin and fenofibrate still need more data to confirm their effects on coronary heart disease prevention. The drugs which were shown to be inferior or insufficient evidence are cerivastatin, gemfibrozil and acipimox.