Abstract
BACKGROUND: Schizophrenia is a chronic mental disorder associated with substantial morbidity and mortality affecting 0.25-1.6% of adults in the USA. Antipsychotic treatment is the standard of care for schizophrenia, but real-world treatment patterns and associated costs have not been systematically reviewed. OBJECTIVE: We conducted a systematic review to summarize treatment patterns and associated costs related to oral antipsychotic treatment of patients with schizophrenia in the USA. DATA SOURCES: We searched Medline (via PubMed) and Embase to identify relevant observational studies published from January 1, 2008, to June 1, 2018; costs were converted to 2018 US dollars. STUDY ELIGIBILITY: Observational, real-world studies reporting on patterns of treatment and/or associated costs for adult patients with schizophrenia treated with oral antipsychotics in the USA were included. RESULTS: Eighty-one studies were identified. Frequently prescribed oral second-generation antipsychotics were olanzapine (up to 50.9%), risperidone (up to 40.0%), and quetiapine (up to 30.7%). Suboptimal adherence was common across studies. Antipsychotic switching occurred in about half of patients, while antipsychotic combination therapy occurred in nearly 30%; all were associated with increased medication-related costs. Mean annual direct medical costs differed by treatment, with reported costs of $17,115 to $26,138 for patients treated with olanzapine, $18,395 for risperidone, and $17,656 to $28,101 for quetiapine. LIMITATIONS: This systematic review is limited by the variations in definitions of schizophrenia-related clinical terms used between studies and by the inclusion of studies focused on only the US health care system. CONCLUSIONS: In the treatment of schizophrenia, suboptimal adherence, antipsychotic switching, and antipsychotic augmentation were all associated with high costs of care in comparison to patients who were adherent and did not require antipsychotic switching or augmentation. These findings illustrate the need for the development of new treatments that address efficacy and adherence challenges of currently available therapies.