Assessment of compliance with antipsychotic treatment and resource utilization in a Medicaid population.

Background: Partial compliance with mental health medications has been associated with an increased risk of clinical worsening, relapse, and repeat hospitalization.

Objective: The purpose of this study was to evaluate the effect of partial compliance of patients (diagnosed as having schizophrenia or bipolar disorder) with prescribed oral atypical and conventional antipsychotic agents and the corresponding impact on resource utilization.

Methods: Patients receiving antipsychotic agents ina large Southeastern Medicaid program were grouped according to their level of compliance. Compliance was measured by the continuous, multiple interval medications available methodology. Patients were deemed partially compliant if compliance was <80%, compliant if compliance was 80% to 125%, and overly compliant if compliance was >125%. Medical costs were modeled as a function of compliance while controlling for background covariates. Logistic regression was used to model the probability of specific resource utilization.

Results: A total of 7864 patients were included in this analysis. After controlling for background covariates, partially compliant patients were 49.0% (95% CI, 29.2%-71.7%) more likely than compliant patients to have an inpatient hospitalization and incurred 54.5% (P < 0.001) higher inpatient charges. Partially compliant patients were also 64% (P < 0.01) more likely than compliant patients to switch or augment therapy.

Conclusion: Partial compliance was associated with an increased risk of hospitalization and switching or augmentation of therapy when compared with being compliant.