The MIRECC Version of the Global Assessment of Functioning Scale: Reliability and Validity

Abstract

This study examined the reliability and convergent, discriminant, and predictive validity of the Mental Illness Research, Education, and Clinical Center (MIRECC) version of the Global Assessment of Functioning (GAF) scale. The MIRECC GAF measures occupational functioning, social functioning, and symptom severity on three subscales. MIRECC GAF ratings were obtained for 398 individuals with schizophrenia or schizoaffective disorder who were receiving treatment at three Veterans Affairs mental health clinics. Assessments were completed by using the Positive and Negative Syndrome Scale and the Quality of Life Interview at baseline and nine months later. All three MIRECC GAF subscales exhibited very high levels of reliability. The occupational and symptom subscales showed good convergent and discriminant validity. The social subscale was related to measures of social functioning and, to a greater degree, symptom severity. The occupational and social subscales significantly predicted their respective domains at the nine-month follow-up. The symptom subscale predicted negative symptoms at follow-up; however, it did not predict positive symptoms or cognitive disorientation. Instead, the social subscale was predictive of cognitive disorientation at follow-up. When the standard GAF was routinely administered by clinicians, scores demonstrated little validity. The three MIRECC GAF subscales can be scored reliably, and they have good concurrent and predictive validity. Further work is needed on brief measures of patient functioning, especially measures of social functioning.