Brief Psychiatric Rating Scale Expanded Version: How do new items affect factor structure?

Velligan, Dawn; Prihoda, Thomas; Dennehy, Ellen; Biggs, Melanie; Shores-Wilson, Kathy; Crismon, M. Lynn; Rush, A. John; Miller, Alexander; Suppes, Trisha; Trivedi, Madhukar; Kashner, T. Michael; Witte, Bradley; Toprac, Marcia; Carmody, Thomas; Chiles, John; Shon, Stephen

doi:10.1016/j.psychres.2005.05.001

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Volume 135, Issue 3 , Pages 217-228, 30 June 2005

Brief Psychiatric Rating Scale Expanded Version: How do new items affect factor structure?

Dawn Velligan
- Department of Psychiatry, University of Texas Health Sciences Center at San Antonio, Mail Stop 7792, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
- Corresponding author. Tel.: +1 210 567 5508; fax: +1 210 567 1291.
Thomas Prihoda
- Department of Psychiatry, University of Texas Health Sciences Center at San Antonio, Mail Stop 7792, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
Ellen Dennehy
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Melanie Biggs
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Kathy Shores-Wilson
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
M. Lynn Crismon
- Department of Psychiatry, University of Texas, Austin, TX, USA
A. John Rush
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Alexander Miller
- Department of Psychiatry, University of Texas Health Sciences Center at San Antonio, Mail Stop 7792, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
Trisha Suppes
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Madhukar Trivedi
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
T. Michael Kashner
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Bradley Witte
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
Marcia Toprac
- Texas Department of Mental Health and Mental Retardation, Austin, TX, USA
Thomas Carmody
- Department of Psychiatry, University of Texas Southwestern Medical School, Dallas, TX, USA
John Chiles
- Department of Psychiatry, University of Washington, Seattle, WA, USA
Stephen Shon
- Texas Department of Mental Health and Mental Retardation, Austin, TX, USA

Received 17 July 2004; received in revised form 14 April 2005; accepted 13 May 2005.

Abstract

Our goal was to suggest a factor structure for the Brief Psychiatric Rating Scale Expanded Version (BPRS-E) based upon a large and diverse sample and to determine which of the new items improved the factors derived from the 18-item version of the scale that have been used in clinical research for decades. We investigated the consistency of our proposed model over time and across demographic groups. As part of the Texas Medication Algorithm Project, the BPRS-E was administered to a total of 1440 psychiatric outpatients in three different diagnostic groups on multiple occasions. The sample was randomly split so that exploratory factor analysis could be done with the first half, and the model could be confirmed on the second half. A four-factor structure including factors assessing depression/anxiety, psychosis, negative symptoms, and activation was found. For each factor, we specify items in the expanded version that added to the breadth of the commonly used clinical factors while improving or maintaining goodness of fit and reliability. The final model proposed was consistent over time and across diagnosis, phase of illness, age, gender, ethnicity, and level of education. The BPRS-E has a stable four-factor structure, making it useful as a clinical outcome measure.

Keywords: Expanded BPRS, Exploratory factor analysis, Confirmatory factor analysis