Meta-analytic exploration of the joint factors of the Brief Psychiatric Rating Scale - Expanded (BPRS-E) and the positive and negative symptoms scales (PANSS).

Previous meta-analyses of the BPRS-E and PANSS were combined to analyze the joint factors across 77 factor analyses from 68 studies of 32,896 individuals. The BPRS-E and PANSS share the 18 original BPRS items and each has additional unique items (6 BPRS-E and 12 PANSS). Based on the combined data across the BPRS-E and PANSS four separate sets of factor analyses were conducted using sample weighting (weighted and unweighted) and matrix type (similarity coefficients and reproduced correlations). Five factors: Positive Symptoms, Affect, Negative Symptoms, Disorganization and Activation-Mania were consistent across all solutions. The factors Positive Symptoms and Affect were defined primarily by the original 18 BPRS items. The factors Negative Symptoms and Disorganization were largely defined by the PANSS additional items. The Activation-Mania factor was largely defined by the additional BPRS-E items. The results were similar to those found in previous meta-analyses but the current factors were substantially more comprehensive and better defined because they included all the items from both the BPRS-E and the PANSS. Future research should consider using all the items from both the PANSS and BPRS-E as the unique items from each scale improve the assessment and measurement of these factors.