Purpose and Scale Analysis

The Global Assessment of Functioning Scale (GAF-100) was developed in 1976 by Spitzer and colleagues. It is used by clinicians to assess the functional status of individuals with mental illness. The scale is applied in clinical psychology and health psychology questionnaires to evaluate the impact of mental health conditions on overall functioning.

Scoring and Statistical Analysis

In the GAF-100, patients are evaluated based on their mental state and the extent to which their condition affects them during a specific time period. The scale ranges numerically from 1 to 100 and is divided into 10-point intervals (1–10 to 91–100). A score of 1 reflects the most severe dysfunction, while a score of 100 indicates optimal mental health. Score interpretations typically follow these ranges: 1–40 for hospitalized patients, 41–70 for non-hospitalized patients with moderate symptoms or difficulties, 71–80 for individuals with no significant psychopathology, and 81–100 for mentally healthy individuals.

Validity and Reliability

The scale was translated into Greek by Madianos (1987). Its reliability was found to be satisfactory, with an intraclass correlation coefficient (ICC) of 0.74 and a standard error (SE) of 5.8. Regarding validity, a correlation coefficient of r = -0.653 (p < 0.001) was reported, indicating strong convergent validity.

References

Endicott, J., Spitzer, R. L., Fleiss, J. L., & Cohen, J. (1976). The Global Assessment Scale: A procedure for measuring overall severity of psychiatric disturbance. Archives of General Psychiatry, 33(6), 766–771.
Velelekou, A. (2020). Investigation of the psychosocial characteristics of psychotic patients and their relationship with length of hospitalization (Master’s thesis).
Madianos, M. (1987). The Global Assessment of Functioning Scale (GAS): Its reliability and validity in the Greek context. Encephalos, 24, 97–100.