Antipsychotic medication use patterns and associated costs of care for individuals with schizophrenia.

BACKGROUND: Schizophrenia is a costly and complicated disorder to treat. A variety of schizophrenia treatment guidelines have been developed to provide valuable expert advice to practicing psychiatrists on various treatment options that are presumed to result in the best outcomes. However, examination of antipsychotic medication use patterns has suggested that current prescribing practices do not mirror recommended treatment guidelines and may have adverse economic consequences. AIM OF THE STUDY: This study seeks to describe antipsychotic medication treatment patterns and estimate the total costs of care associated with treatment patterns for individuals diagnosed with schizophrenia in usual care settings. METHODS: Use of outpatient antipsychotic medications and other health services during 1997 was obtained for 2,082 individuals with a diagnosis of schizophrenia in the IMS Health LifeLink employer claims database. We describe outpatient antipsychotic treatment patterns, estimated the costs of schizophrenia care by treatment pattern, and compared costs by treatment pattern using regression models. RESULTS: During 1997, 26% (n=536) of individuals diagnosed with schizophrenia received no antipsychotic medication in the outpatient setting, while 52% (n=1,088) were treated with only one antipsychotic (Monotherapy). For individuals who received more than one antipsychotic medication during 1997 (n=458), 13% (n=262) switched antipsychotic medications (Switch), 7% (n=154) augmented their original antipsychotic therapy with an additional antipsychotic (Augment), and 2% (n=42) of individuals were on more than one antipsychotic therapy at the start of the year. After adjusting for covariates, Switch and Augment patterns were associated with significant increases in total costs (an increase of 4,706 dollars (p<0.0001) and 4,244 dollars (p=0.0002), respectively) relative to Monotherapy. DISCUSSION: These results indicate that a substantial proportion of individuals with a diagnosis of schizophrenia were not treated with or had low exposure to antipsychotic therapy. Individuals treated with antipsychotic monotherapy experienced nearly half the annual costs as individuals who were treated with antipsychotic polytherapy or who switched antipsychotic medications. These observations should be interpreted in the context of the study limitations. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE: This analysis indicates that there may be considerable room for improvement in the treatment for individuals diagnosed with schizophrenia. IMPLICATIONS FOR HEALTH POLICIES: Though schizophrenia affects a very small portion of the population, the individual and societal burden associated with the disorder is quite high. This paper suggests that antipsychotic monotherapy and continuous therapy, commonly recommended by published treatment guidelines, may be associated with economic savings. IMPLICATIONS FOR FURTHER RESEARCH: Future research should evaluate the impact of newer antipsychotic medications on patterns of care and economic outcomes. More information is also needed on which individual patient characteristics are likely to predict success or failure on specific treatments. Finally, more detailed information on the reasons or rationale for switching or augmenting original pharmacotherapy would be valuable in improving medication management in these complex and often difficult to treat patients.