Concomitant antipsychotic prescribing in US outpatient settings
published online 22 January 2009.
Abstract
Background
Clinicians use concomitant antipsychotic therapy for management of psychotic disorders despite a paucity of evidence for this practice.
Objective
To examine national patterns and determinants of concomitant antipsychotic therapy.
Methods
Concomitant antipsychotic therapy was defined as simultaneous use of 2 or more antipsychotic agents. Prescription data from the 2003-2004 National Ambulatory Medical Care Survey and the outpatient department portion of the 2003-2004 National Hospital Ambulatory Medical Care Survey were used to characterize the prescribing of concomitant antipsychotic therapy and antipsychotic monotherapy (defined as use of a typical or atypical agent). Multiple logistic regression was applied to antipsychotic visits to examine the determinants of concomitant antipsychotic therapy based on patient and provider characteristics.
Results
Overall, concomitant antipsychotic therapy was documented in 9% of the visits involving antipsychotic agents, and monotherapy in 91% of the visits. The use of atypical agents, namely risperidone, olanzapine, and quetiapine, was common in both forms of therapy. Concomitant therapy was frequently used for psychoses and bipolar disorder. Logistic regression revealed that the odds of receiving concomitant antipsychotic therapy were higher for patients younger than 65 years, with greatest odds (odds ratio=6.52) for patients 40 to 64 years old. Having a diagnosis of psychosis quadrupled (odds ratio=4.33) the odds of receiving concomitant antipsychotic therapy. Physicians in metropolitan areas were more likely (odds ratio=2.17) to use concomitant antipsychotic therapy than physicians in non-metropolitan areas.
Conclusions
Concomitant antipsychotic therapy continues to be prevalent and extensive in outpatient settings. With the use of concomitant antipsychotic therapy as a quality of care measure, there is a need to optimize prescribing of these potent combinations.
aDepartment of Clinical Sciences and Administration, College of Pharmacy, University of Houston, 1441 Moursund Street, Texas Medical Center, Houston, TX 77030, USA
bDepartment of Clinical Sciences and Administration, College of Pharmacy, University of Houston, TX 77030, USA
cDepartment of Psychiatry, University of South Dakota Sanford School of Medicine, Sioux Falls, SD 57105, USA
Corresponding author. Tel.: +713 7959374.
The authors have no relevant financial interest to declare. No funding was received for this study.
Presented in part at the 2007 Annual Meeting of the American Pharmacists Association, Atlanta, GA, March 2007.
ABSTRACT