The heterogeneity of schizophrenia in disease states

Mohr, Penny E.; Cheng, C.Michael; Claxton, Karl; Conley, Robert R.; Feldman, Jacob J.; Hargreaves, William A.; Lehman, Anthony F.; Lenert, Leslie A.; Mahmoud, Ramy; Marder, Stephen R.; Neumann, Peter J.

doi:10.1016/j.schres.2003.11.008

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Volume 71, Issue 1 , Pages 83-95, 1 November 2004

The heterogeneity of schizophrenia in disease states

Penny E. Mohr
- Corresponding author. Centers for Medicare and Medicaid Services, ORDI/REG/DBR, Mail stop C3-19-07 7500, Security Boulevard, Baltimore, MD 21244, USA. Tel.: +1-301-656-7401; fax: +1-301-654-0629.
- Centers for Medicare and Medicaid Services, ORDI/REG/DBR, Mail stop C3-19-07 7500, Security Boulevard, Baltimore, MD 21244, USA
C.Michael Cheng
- PacifiCare, Medical Informatics, 5757 Plaza Drive, Mail Stop CY44-176 Cypress, CA 40630, USA
Karl Claxton
- University of York, Department of Economics, Heslington, York, UK
Robert R. Conley
- Maryland Psychiatric Research Center, Baltimore, MD, USA
Jacob J. Feldman
- Senior Fellow NORC, 7500 Old Georgetown Road, Suite 620, Bethesda, MD, 20814, USA
William A. Hargreaves
- UC-SF, School of Medicine, Department of Psychiatry, San Francisco, CA, USA
Anthony F. Lehman
- U-MD, School of Medicine, Department of Psychiatry, Baltimore, MD, USA
Leslie A. Lenert
- UC-SD, School of Medicine, Health Services Research and Development, San Diego, CA, USA
Ramy Mahmoud
- Janssen Pharmaceutica Products, L.P., Medical Development, Titusville, NJ, USA
Stephen R. Marder
- Mental Illness Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, USA
Peter J. Neumann
- Harvard School of Public Health, Boston, MA, USA

Received 29 May 2003; received in revised form 7 November 2003; accepted 12 November 2003.

Abstract

Previous presentation: Some of the contents of this paper have been previously presented at the 16th Annual Meeting of the International Society for Technology Assessment in Health Care June 20, 2000 in the Hague, Netherlands and at the 21st Annual Meeting of the Society for Medical Decision Making as a poster on October 3, 1999 in Reno, NV. Background: Studies of schizophrenia treatment often oversimplify the array of health outcomes among patients. Our objective was to derive a set of disease states for schizophrenia using the Positive and Negative Symptom Assessment Scale (PANSS) that captured the heterogeneity of symptom responses. Methods: Using data from a 1-year clinical trial that collected PANSS scores and costs on schizophrenic patients (N=663), we conducted a k-means cluster analyses on PANSS scores for items in five factor domains. Results of the cluster analysis were compared with a conceptual framework of disease states developed by an expert panel. Final disease states were defined by combining our conceptual framework with the empirical results. We tested its utility by examining the influence of disease state on treatment costs and prognosis. Results: Analyses led to an eight-state framework with varying levels of positive, negative, and cognitive impairment. The extent of hostile/aggressive symptoms and mood disorders correlated with severity of disease states. Direct treatment costs for schizophrenia vary significantly across disease states (F=27.47, df=7, p<0.0001), and disease state at baseline was among the most important predictors of treatment outcomes. Conclusion: The disease states we describe offer a useful paradigm for understanding the links between symptom profiles and outcomes.

Keywords: Schizophrenia, Outcome assessment, Prognosis, Treatment costs