Minimum Clinically Important Difference in the Global Assessment Functioning in Patients with Schizophrenia.

CONCLUSIONS • Despite extensive use of the GAF to evaluate functioning in patients with schizophrenia, this is the first empirical documentation of minimal clinically important difference thresholds, using distribution-based and anchor-based approaches. • Results range from 2.9 (within-patients score approach) to 11.7 (SD approach). • We suggest using a MCID of 10, based on the SEM approach. This is similar to the cut-offs used in the GAF scoring form. • A consensus on MCID preferred methodology is needed.