Article Abstract

Article Abstract

Online ISSN: 1099-176X Print ISSN: 1091-4358
The Journal of Mental Health Policy and Economics
Volume 19, Issue 1, 2016. Pages: 45-59
Published Online: 1 March 2016

Patient, Physician and Organizational Influences on Variation in Antipsychotic Prescribing Behavior

Yan Tang,¹* Chung-Chou H. Chang,² Judith R. Lave,³ Walid F. Gellad,⁴ Haiden A. Huskamp,⁵ Julie M. Donohue⁶

¹Ph.D., Center for Pharmaceutical Policy and Prescribing (CP3), Health Policy Institute, University of Pittsburgh; Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
²Ph.D., Professor, Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, PA, USA
³Ph.D., Professor Emerita, Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh, PA, USA
⁴MD, MPH, Associate Professor, VA Pittsburgh Healthcare System; Center for Pharmaceutical Policy and Prescribing (CP3), Health Policy Institute, University of Pittsburgh; Division of General Medicine, University of Pittsburgh, PA, USA
⁵Ph.D., Professor, Department of Health Care Policy, Harvard Medical School, MA, USA
⁶Ph.D., Associate Professor, Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh; Center for Pharmaceutical Policy and Prescribing (CP3), Health Policy Institute, University of Pittsburgh, PA, USA

* Correspondence to: Yan Tang, Ph.D., Center for Pharmaceutical Policy and Prescribing (CP3), Health Policy Institute, University of Pittsburgh; Department of Health Policy and Management, Graduate School of Public Health, University of Pittsburgh, PA, USA, 130 DeSoto Street, Crabtree Hall A645, Pittsburgh, PA 15261, USA.
Tel.: +1-412-624 3125
Fax: +1-412-624 3146
E-mail: yan.tang@pitt.edu

Source of Funding: This work was supported in part by grant R01MH093359 from the National Institute of Mental Health (Drs. Donohue and Huskamp), and by an inter-governmental agreement between the Pennsylvania Department of Human Services and the University of Pittsburgh. Dr. Huskamp serves on the Academic Advisory Committee for the Health Services Research Network at IMS Health Inc. (uncompensated). The other authors report no conflict of interest. Some of the findings were presented at the International Society of Pharmacoeconomics and Outcomes Research 20th Annual International Meeting, May 16-20, 2015, Philadelphia, PA, USA.

Abstract

Physicians face the choice of over 20 ingredients when prescribing antipsychotic medications. Personalized prescribing is of great importance given considerable patient heterogeneity in antipsychotic treatment response. Using Pennsylvania’s Medicaid data, IMS Health’s HCOS^TM database, and the AMA Masterfile, this paper studies variation in psychiatrists’ prescribing of antipsychotics and the influence of patient characteristics, physician characteristics, and organizational features on the diversity/concentration of antipsychotic prescribing. There was substantial variability in antipsychotic prescribing concentration, with share for most preferred ingredient ranging from 16%-85%. On average, psychiatrist prescribing behavior was relatively diversified; however, 11% of psychiatrists wrote an average of 55% of their prescriptions for their most preferred ingredient. Female physicians and those with smaller shares of disabled or serious mental illness patients had more concentrated prescribing behavior. Our findings indicate that even among specialties regularly prescribing a therapeutic category, some rely heavily on a small number of agents.

Background: Physicians face the choice of multiple ingredients when prescribing drugs in many therapeutic categories. For conditions with considerable patient heterogeneity in treatment response, customizing treatment to individual patient needs and preferences may improve outcomes.

Aims of the Study: To assess variation in the diversity of antipsychotic prescribing for mental health conditions, a necessary although not sufficient condition for personalizing treatment. To identify patient caseload, physician, and organizational factors associated with the diversity of antipsychotic prescribing.

Methods: Using 2011 data from Pennsylvania's Medicaid program, IMS Health's HCOS^TM database, and the AMA Masterfile, we identified 764 psychiatrists who prescribed antipsychotics to ³ 10 patients. We constructed three physician-level measures of diversity/concentration of antipsychotic prescribing: number of ingredients prescribed, share of prescriptions for most preferred ingredient, and Herfindahl-Hirschman index (HHI). We used multiple membership linear mixed models to examine patient caseload, physician, and healthcare organizational predictors of physician concentration of antipsychotic prescribing.

Results: There was substantial variability in antipsychotic prescribing concentration among psychiatrists, with number of ingredients ranging from 2-17, share for most preferred ingredient from 16%-85%, and HHI from 1,088-7,270. On average, psychiatrist prescribing behavior was relatively diversified; however, 11% of psychiatrists wrote an average of 55% of their prescriptions for their most preferred ingredient. Female prescribers and those with smaller shares of disabled or serious mental illness patients had more concentrated prescribing behavior on average.

Discussion: Antipsychotic prescribing by individual psychiatrists in a large state Medicaid program varied substantially across psychiatrists. Our findings illustrate the importance of understanding physicians' prescribing behavior and indicate that even among specialties regularly prescribing a therapeutic category, some physicians rely heavily on a small number of agents.

Implications for Health Policies, Health Care Provision and Use: Health systems may need to offer educational interventions to clinicians in order to improve their ability to tailor treatment decisions to the needs of individual patients.

Implications for Future Research: Future studies should examine the impact of the diversity of antipsychotic prescribing to determine whether more diversified prescribing improves patient adherence and outcomes.

Received 27 August 2015; accepted 7 December 2015