The Brief Psychiatric Rating Scale: Schizophrenia, Reliability and Validity Studies

Abstract

In an attempt to increase uniformity and unambiguity of evaluation through rating scales of schizophrenia and schizophrenialike psychosis, the 5-step edition of the Brief Psychiatric Rating Scale (BPRS) is used. In this edition of BPRS the 18 symptoms and the symptom grading are expressed in explicit item definitions. Symptoms in the Hamilton Depression Scale and in the Beigel Mania Scale which correlate with BPRS have been incorporated as far as possible. Despite wide international application of BPRS, only few reliability and validity studies have been made, the fact notwithstanding that the scale is used as a reference when new scales are introduced.

This interim statement includes weekly co-rating of in-patients on the BPRS. The studies were commenced in August 1984. The rating procedure takes place between 8.15 and 9.00 a.m. and each patient is examined only once. The maximum number of raters is six but varies between three and six per rating procedure. The evaluated patients all comply with DSM-III criteria for schizophrenia.

Reliability is expressed by intra-class correlation R = 0.78, p. < 0.001, for the total scale. When considering degree of severity the global estimate (validity) showed a correlation of R = 0.66, p. < 0.01. After 18 weeks of co-ratings all other schizophrenic in-patients - a total of 17 - were rated as a control group. There was no difference between the two populations of schizophrenic patients, t = 0.92, p = 0.36.

Key Words:

• Schizophrenia
• reliability
• validity studies