Psychometric evaluation of a standardized and expanded Brief Psychiatric Rating Scale

The interrater reliability, factorial and discriminant validity of a standardized and expanded Brief Psychiatric Rating Scale (BPRS-E) were investigated in a heterogeneous short-stay group of psychiatric inpatients in the Netherlands (n = 162). Repeated separate interviews by single clinicians (psychiatrists, residents or clinical psychologists), best reflecting the way the BPRS is usually employed in clinical practice and psychopharmacological research, were used to determine interrater reliability (n = 79). Although the 5 subscales of the original 18-item BPRS (BPRS-18) were successfully cross-validated in this Dutch sample, 4 of these subscales (except for thought disturbance) were found to lack interrater reliability. The 10-item schizophrenia scale derived from the BPRS-18 by a Scandinavian group met the standard of acceptable interrater reliability; BPRS-18 and BPRS-E global scales approximated this standard. For the thought disturbance subscale, the schizophrenia scale and for BPRS-18 and BPRS-E global scales, findings supported discriminatory power.