Predictors of antipsychotic polypharmacy in an acute-care teaching hospital

Abstract

Introduction: Antipsychotic polypharmacy increases the risk of adverse reactions, interactions, and cost. Data for the use of antipsychotic polypharmacy are limited. The Joint Commission’s Hospital Based Inpatient Psychiatric Services (HBIPS) recently established a set of quality measures evaluating inpatient psychiatric care, including the rate of antipsychotic polypharmacy at discharge.Methods: A retrospective medical record review was approved by the Institutional Review Board. Admission records were used to identify patients 18 years or older who were discharged from an inpatient psychiatric unit from January 1, 2012 to June 30, 2012. Exclusion criteria included patients not discharged on antipsychotics, pregnancy, length of stay not more than three days, elopement or failing to return from leave, or those who expired. Patients were divided into two groups: those discharged on antipsychotic monotherapy or antipsychotic polypharmacy. The objective of this study was to determine the association between patient-specific factors and the presence of antipsychotic polypharmacy at discharge. A secondary objective was determining if appropriate justification for antipsychotic polypharmacy at discharge was documented.Results: Of 901 inpatient psychiatric admissions, 442 patients were included. There were 362 patients discharged on antipsychotic monotherapy and 80 patients discharged on antipsychotic polypharmacy. Five characteristics were significantly associated with antipsychotic polypharmacy at discharge: Medicare insurance (OR 2.156, 95% CI 1.279-3.636), psychotic disorders (OR 3.665, 95% CI 1.999-6.789), greater than one antipsychotic on admission (OR 27.179, 95% CI 13.895-53.668), quetiapine at discharge (OR 2.3, 95% CI 1.355-3.901), and paliperidone at discharge (OR 2.415, 95% CI 1.38-4.219). Of the 80 patients discharged on antipsychotic polypharmacy, 83.7% did not have appropriate justification for the polypharmacy documented.Conclusions: The patient-specific factors of Medicare, psychotic disorders, greater than one antipsychotic on admission, and quetiapine and paliperidone were significantly associated with antipsychotic polypharmacy at discharge. For patients discharged on multiple antipsychotics, supporting documentation was infrequent.