Background:
The Clinical Global Impression (CGI) scale is an established outcome measure in psycho-pharmacology research and has been applied to specific disorders, including schizophrenia, anxiety disorders, depression and bipolar disorder. Its simplicity and ability to transcend diagnostic boundaries support its utility in the general clinical setting. This study was conducted to test the validity of the CGI in a private psychiatric in-patient setting.
Methods:
Consecutive admissions (n = 786) to a private psychiatric hospital from January 2004 to December 2005 were studied. Retrospective data were collected on four outcome measures that were routinely administered at admission and discharge. These were the self-rated 21-item Depression Anxiety Stress Scales (DASS-21) and the Mental Health Questionnaire (MHQ-14), and the clinician-rated CGI and Health of the Nation Outcome Scales (HoNOS). In relation to the CGI, only the severity (CGI-S) and global improvement (CGI-I) subscales were used. Comparative statistical analyses were performed.
Results:
The numbers of completed CGI ratings were 624 admission CGI-S, 614 discharge CGI-S and 610 CGI-I. The admission and discharge CGI-S scores were correlated (r = 0.40), and the indirect improvement measures obtained from their differences were highly correlated with the direct CGI-I scores (r = 0.71). The CGI-S categories reflected similar trends in scores on the other three measures, and the CGI-I showed parallel changes with improvement on HoNOS.
Conclusions:
The CGI-S and CGI-I are comparable to other measures of illness severity and improvement. They appear to be valid instruments in the private psychiatric in-patient setting.