Cost-effectiveness and cost-benefit analysis

In the United States, second-generation antipsychotics have become the most widely used drugs in the treatment of schizophrenia, with total annual costs in 2007 of over $12 billion. Earlier studies of patients with chronic schizophrenia reported that these medications were not only more effective than older drugs with fewer side effects, but that they also lowered the risk of hospitalization, generating sufficient savings to offset their greater drug costs entirely. However, many of these studies were based on non-experimental designs, and a small number of randomized trials showed either much smaller net savings or even increased total costs. Two more recent 12-month trials failed to find advantages for the newer drugs in either clinical effectiveness, reduced Parkinsonian side effects, or lowered costs, and an economic analysis showed increased costs to the California Medicaid program in association with the introduction of these medications. A recent literature review of cost-effectiveness studies involving second-generation antipsychotics also failed to find evidence of greater cost-effectiveness for these agents To further evaluate the cost-effectiveness of these medications, the Clinical Antipsychotic Trial of Intervention Effectiveness (CATIE) schizophrenia trial included extensive data collection on health service use to allow estimation of health care costs incurred by study participants, along with several measures of effectiveness, including a disease-specific estimate of quality-adjusted life years (QALYs), that together would support a comparative analysis of the cost-effectiveness of one first-generation antipsychotic (perphenazine) and all four second-generation antipsychotics (olanzapine, risperidone, quetiapine, and ziprasidone), with the exception of clozapine, that were available in the US in 2001–2004 when CATIE was implemented.