Remission Rates and Criteria for Clinical Studies on Schizophrenia

Chung, Seockhoon; Bahk, Won Myong; Kwon, Jun Soo; Kang, Shi Hyun; Joo, Yeon Ho; Ahn, Joon Ho; Kim, Chang Yoon

Abstract

OBJECTIVE
Standardizing remission criteria is helpful for documenting patient remission states by setting appropriate treatment goals and comparing the efficacy of various therapies. We investigated the applicability of two remission criteria through a 1-year prospective observational study on patients with recent-onset schizophrenia.
METHODS
Forty-nine patients were enrolled and assessed monthly using the BPRS, SAPS, SANS, and CGI. Criteria A included a BPRS total score of < or =36, a BPRS psychotic item score of < or =3, and a CGI-S score of < or =3. Criteria B included all of five global items in the SAPS and SANS of < or =2 (mild). Each remission criterion was required to be met for at least 2 consecutive months.
RESULTS
The remission rates at study endpoint were 64.3 and 42.9%, respectively, when criteria A and B were applied. Within criteria A, the remission rate was 78.6% when only a BPRS total score criterion was applied, which then dropped to 75.0% when a BPRS psychotic item criterion was added. A 75% remission rate was noted when the CGI criterion was independently applied. Within criteria B, a 71.4% remission rate was observed using the SAPS criterion, which decreased to 42.9% when a SANS score criterion was added. No significant difference was detected in the time to remission and the duration of maintained remission when criteria A or B were applied.
CONCLUSION
The SAPS and SANS scales are stricter for categorizing the remission state compared to the BPRS and CGI. Criteria based on the BPRS appear to be more representative of the remission state when a BPRS psychotic item criterion is added. In addition, CGI alone can be used for longterm follow-up evaluations of patients with schizophrenia.