Children's Global Assessment Scale (CGAS)

Overview

The Children’s Global Assessment Scale (CGAS), adapted from the Global Assessment Scale for adults, is a rating of general functioning for children and young people aged 4-16 years old. The clinician assesses a range of aspects of psychological and social functioning and gives the child or young person a single score between 1 and 100, based on their lowest level of functioning. The score puts them in one of ten categories that range from “needs constant supervision” (1-10) to “superior functioning” (91-100). The measure can be used by clinicians as well as researchers to complement other scales measuring more specific symptoms.

Terms of use

The CGAS was developed by Shaffer and colleagues at the Department of Psychiatry, Columbia University.

If you are planning to use this measure for the delivery and improvement of health and/or social care, a licence to incorporate it into electronic systems can be obtained from NHS Digital. Please note that licences obtained via this route may be restricted to particular territories (e.g. England, UK). If planning to use the measure outside of England, you may wish to contact NHS Digital to clarify the geographical scope of the licence.

Scales / Subscales

See Shaffer et al. (1983) for CGAS items and examples.

Suitability

The CGAS is used to assess children and young people aged 4 to 16 years and is completed by clinicians.

The CGAS is adapted from the Global Assessment Scale, which is used for adults.

The CGAS has been modified for use with children with developmental disabilities (DD-CGAS).

There is also a version of the CGAS for assessing parent-infant relationships (PIRGAS).

To our knowledge, no study has been published regarding the suitability of the measure for children and young people in the UK and across different ethnic or linguistic groups. Some studies have indicated preliminary applicability internationally and across cultures (Bird et al., 1987; Hanssen-Bauer et al., 2007).

Please do get in touch at CORC@annafreud.org if you are aware of any information that may be of interest to users of the measure as we may be able to update our webpage to include it.

Administration

The CGAS is a clinician reported outcome measure. There is one item on the CGAS on a scale from 0 to 100, broken down into categories. The clinician needs to gather information from prior assessments, and interviews with the child, parents and carers and school. Global functioning is then assessed based on the child’s lowest level of functioning in a specified time period, which is usually the preceding month).

CGAS Scale

More details on administering, scoring and interpreting the Developmental Disability-Children’s Global Assessment Scale (DD-CGAS) can be found in this article. Further information on the Parent-Infant Relationship Global Assessment Scale is available here.

Further information

Free web-based training for the CGAS including practice examples is available here.

Working remotely

As far as we know, adaptations and derivatives are not authorised without written permission from the developer. Regarding any adaptations, the instrument may not be altered to remove the copyright or other text in the margins regarding the source and terms.

For more information of working remotely with outcome measures, please read our guide: https://www.corc.uk.net/outcome-experience-measures/using-outcome-and-experience-measures-remotely/

Scoring and Interpretation

The CGAS asks the clinician to rate the child from 1 to 100 based on their lowest level of functioning, regardless of treatment or prognosis, over a specified time period.

The following score ranges are defined by Shaffer et al. (1983), who advise using intermediary levels (e.g. 34, 52, 65):

1-10: Needs constant supervision (24 hour care)
11-20: Needs considerable supervision
21-30: Unable to function in almost all areas
31-40: Major impairment in functioning in several areas and unable to function in one of these areas
41-50: Moderate degree of interference in functioning in most social areas or severe impairment of functioning in one area
51-60: Variable functioning with sporadic difficulties or symptoms in several but not all social areas
61-70: Some difficulty in a single area, but generally functioning pretty well
71-80: No more than slight impairment in functioning
81-90: Good functioning in all areas
91-100: Superior functioning

Psychometric properties

Property	Definition	CGAS
Internal consistency	Degree to which similar items within a scale correlate with each other.	No information available
Construct validity	Degree to which the questionnaire actually measures the specific trait or attribute it is intended to measure.	No information available
Test-retest reliability	Degree to which the same respondents have the same score after period of time when trait shouldn't have changed.	Early research on the CGAS showed that raters were consistent over time (Shaffer et al., 1983). Analyses of mean scores across two periods showed no significant differences across time (Shaffer et al., 1983).
Convergent validity	Degree to which two measures of constructs that theoretically should be related are in fact related.	Early research on the CGAS showed moderate correlations with the Conners index, another measure of functioning (Shaffer et al., 1983).
Concurrent validity	Correlation of the measure with others measuring same concept.	Comparisons to measures of adaptive functioning, severity of psychopathology, behaviour problems, and social competence showed strong correlations in early research (Bird et al., 1987). CGAS ratings were significantly related to measures of competence, but not symptomatology, in psychiatric inpatients (Green et al., 1994).
Discriminant validity	Lack of correlation with opposite concepts.	Early research on the CGAS showed that it is sensitive to differences in functioning between inpatient and outpatients, as well as to degree of impairment in clinical and nonclinical populations (Shaffer et al., 1983; Bird et al., 1987).

Translation

The CGAS is originally available in English, and has been translated into Spanish (Ezpeleta, L. et al., 1999) and Swedish (Lundh, A. et al., 2010).

References

Bird, H., Canino, G., Rubio-Stipec, M., & Ribera, J. (1987). Further Measures of the Psychometric Properties of the Children’s Global Assessment Scale. Archives of General Psychiatry, 44, 821-824.

Ezpeleta, L., Granero, R., & de la Osa, N. (1999). Assessment of impairment in children and adolescents with the Children's Global Assessment Scale (CGAS). [Spanish]. Revista de Psiquiatria Infanto-Juvenil, 1, 18-26.

Green, B., Shirk, S., Hanze, D., & Wanstrath, J. (1994). The Children's Global Assessment Scale in clinical practice: An empirical evaluation. Journal of the American Academy of Child & Adolescent Psychiatry, 33(8), 1158-1164.

Hanssen-Bauer, K., Gowers, S., Aaelen, O., Bilenberg, N., Brann, P., Garralda, E., Merry, S., & Heyerdahl, S. (2007). Cross-National Reliability of Clinician-Rated Outcome Measures in Child and Adolescent Mental Health Services. Administration and Policy in Mental Health and Mental Health Services Research, 34, 513-518.

Lundh, A., Kowalski, J., Sundberg, C. J., Gumpert, C., & Landén, M. (2010). Children's Global Assessment Scale (CGAS) in a naturalistic clinical setting: Inter-rater reliability and comparison with expert ratings. Psychiatry research, 177(1-2), 206–210. https://doi.org/10.1016/j.psychres.2010.02.006

Shaffer, D., Gould, M.S., Brasic, J., Ambrosini, P., Fisher, P., Bird, H., & Aluwahlia, S. (1983). A Children’s Global Assessment Scale (CGAS). Archives of General Psychiatry, 40, 1228-1231.