What is the CGI?

The Clinical Global Impression (CGI) measure was initially devised in 1976 (Guy, 1976) and has been extensively used to assess the clinical outcomes for both adults and children. It has been particularly well used in pharmacological studies.

The major advantage of this measure is its face validity and extreme simplicity. The measure consists of two scales which are rated by the treating clinician.

CGI-S - Severity: at Treatment Start, at 3 months, and at Treatment End

The CGI-S is a seven point scale of the severity of the clinical problem;
1=Normal
2=Close to normal
3=Mild
4=Moderate
5=Quite severe
6=Severe
7=Very severe

CGI-I - Improvement: at Treatment Close

The CGI-I is a seven point scale of the amount of improvement during or at the end of treatment.
1=Very much improved
2=Much improved
3=Mildly improved
4=No improvement
5=Mildly worse
6=Moderately worse
7=Very much worse

Psychometric properties of the CGI

The CGI is used in a huge number of studies, mainly drug trials. However, it is also used in treatment evaluation in adult and child psychiatry. The validity of the CGI was recently evaluated by on an adult series of 786 psychiatric in-patient admissions (patients aged from 16-91 years) for which the CGI was compared with HONOS, the MHQ and DASS-21 (Berk et al., 2008). The MHQ and the DASS are patient rated measures. The CGI-I correlated 0.71 with measures of change from these other standardised instruments. However, the limitations of such a simple scale have also been recognised (Beneke & Rasmus, 1992).

The CGI has been used in recent child mental health outcome studies on OCD (Coskun & Zoroglu, 2009), Depression (March, Entusah, Rynn, Albano, & Tourian, 2007), Anxiety (March et al., 2007)and ADHD (Schachar et al., 2008). These studies range from pre-school children through to adolescents.

Use of CGI in AMBIT

For AMBIT, it is suggested that the CGI-S could be rated by clinicians at the beginning of treatment, at three months and then at discharge. The CGI-I could be rated at discharge.

References:

Beneke, M. & Rasmus, W. (1992). "Clinical Global Impressions" (ECDEU): Some critical comments. Pharmacopsychiatry, 171-176.

Berk, M., Ng, F., Dodd, S., Callaly, T., Campbell, S., Bernardo, M. et al. (2008). The validity of the CGI severity and improvement scales as measures of clinical effectiveness suitable for routine clinical use. Journal of Evaluation in Clinical Practice, 979-983.

Coskun, M. & Zoroglu, S. (2009). Efficacy and safety of fluoxetine in preschool children with obsessive-compulsive disorder. Journal of Child and Adolescent Psychopharmacology, 297-300.

Guy, W. (1976). ECDEU Assessment Manual for Psychopharmocology - Revised. U.S. Department of Health, Education and Welfare, Public Health Service, Alcohol, Drug Abuse and Mental Health Administration, NIMH.

March, J. S., Entusah, A. R., Rynn, M., Albano, A. M., & Tourian, K. A. (2007). A randomized controlled trial of venlafaxine ER versus placebo in pediatric social anxiety disorder. Biological Psychiatry, 1149-1154.

Schachar, R., Ickowicz, A., Crosbie, J., Donnelly, G. A. E., Reiz, J. L., Miceli, P. C. et al. (2008). Cognitive and behavioral effects of multilayer-release methylphenidate in the treatment of children with attention-deficit/hyperactivity disorder. Journal of Child and Adolescent Psychopharmacology, 11-24.