Partial compliance with antipsychotics increases mental health hospitalizations in schizophrenic patients: analysis of a national managed care database

Abstract

Objective: To investigate the relationship between partial compliance with antipsychotic medication and mental health hospitalization in managed care patients with schizophrenia.

Study design: We performed a retrospective evaluation of 1499 outpatients with ≥1 antipsychotic claims and a diagnosis of schizophrenia in a managed care database (PHARMetrics).

Methods: Patients were followed for 12 months after their initial oral antipsychotic prescribing event. Compliance was estimated by gaps in medication therapy, medication consistency and persistence, and medication possession ratio. Categorical and logistic regression analyses modeled effects of compliance, age, and gender on hospitalization risk.

Results: The managed care cohort had an overall hospitalization risk of 5.9% during follow-up. Increased hospitalization risk was associated with lower partial compliance, as measured by 3 of the 4 definitions. Patients with a maximum gap of >30 days were 4.7 times more likely to be hospitalized than those with a maximum gap of 0 to 10 days (P <.001). Low medication consistency of <70% and a medication possession ratio of <70% were significantly associated with increased risk of hospitalization (P <.001). Logistic regression analyses indicated that hospitalization odds decreased 16.9% (P <.001) and 18.8% (P <.001) for every 10% increase in medication possession ratio and medication consistency, respectively.

Conclusion: Small decreases in compliance with antipsychotics are associated with increased hospitalization risk among patients with schizophrenia in a managed care population.

Figure 1. Hospitalization Rate as Measured by Maximum Gap (Days) in Medication Therapy

Figure 2. Hospitalization Rate as Measured by MPR, Consistency, and Persistence

Peter J. Weiden