Background: Despite the widespread use of the Brief Psychiatric Rating Scale (BPRS), the clinical meaning of its total score and cut-off values used to define treatment response are unclear.
Aims: To link the BPRS to Clinical Global Impression (CGI) ratings.
Method: Equipercentile linking of BPRS and CGI ratings from seven drug trials in acutely ill patients with schizophrenia (n=1979).
Results: 'Mildly ill' according to the CGI approximately corresponded to a BPRS total score of 31, 'moderately ill'to a BPRS score of 41 and'markedly ill'to a BPRS score of 53.'Minimally improved'according to the CGI score was associated with percentage BPRS reductions of 24, 27 and 30% at weeks 1, 2 and 4, respectively. The corresponding numbers for a CGI rating of 'much improved' were 44, 53 and 58%.
Conclusions: The results provide a clearer understanding of how to interpret BPRS total and percentage reduction scores in clinical trials with patients acutely ill with schizophrenia who are experiencing positive symptoms.