Objective: To characterize real-world patterns of persistence in patients with schizophrenia treated with antipsychotic (AP) monotherapy vs AP polypharmacy.
Methods: We examined commercial claims from 01/01/2007 to 04/30/2010 using the HealthCore Integrated Research Database. Patients (N=4156) 13-64 years old with ≥2 claims for schizophrenia and treated with APs (2nd and/or 1st generation) were followed for 1 year. Groups were categorized as: AP monotherapy (1 antipsychotic: 77%) and AP polypharmacy (2+ antipsychotics: 23%). Differences in therapy duration, and proportions of patients discontinuing were analyzed. Regression analyses were used to predict discontinuation before 12 months, and therapy duration.
Results: Most patients discontinued AP therapy prior to 1-year follow-up (77% polypharmacy vs 53% monotherapy patients). 50% of polypharmacy patients discontinued AP treatment (1 or more APs) before 3 months vs 17% of monotherapy patients. Mean therapy duration was significantly shorter for polypharmacy than monotherapy patients. 69% of monotherapy patients <26 years old discontinued by 12 months vs 47% of monotherapy patients >45 years. Among polypharmacy patients, 88% of patients <26 years, and 72% of patients >45 years discontinued prior to 1 year. Both age and polypharmacy use were independent predictors of therapy duration and discontinuation by 12 months. In addition, having ≥3 additional psychiatric medications was associated with shorter therapy duration.
Conclusion: Persistence with AP therapy is low, especially among younger patients and patients on polypharmacy. Continuance differences by age and type of therapy may be due to differences in disease severity.