Outcome in Psychiatric Outpatient Services Reliability, Validity and Outcome Based on Routine Assessments with the Gaf Scale

Söderberg, Per & Tungström, Stefan (2007). Outcome in psychiatric outpatient services: Reliability, validity and outcome based on routine assessments with the GAF scale. Doctoral dissertation from the Department of Psychology, Umeå University, S-901 87 UMEÅ, Sweden: ISBN 91-7264-240-8; ISBN 978-91-7264-240-9 The general aim of the studies presented in this thesis is to investigate the possibility of using clinical data to measure outcomes in psychiatric outpatient services. The specific aims are to investigate whether routine clinical assessments and ratings are reliable and have adequate validity, and then to use these data to calculate treatment outcomes and explore factors that affect these outcomes. The main result shows that ratings of global mental health made by clinicians in routine clinical work can be used to evaluate treatment outcomes in outpatient settings. The clinicians responsible for diagnosing and assessing patients used the GAF scale with satisfactory reliability (ICC1,1 = 0.81) and fair interrater reliability (overall kappa = 0.53) when categorizing main diagnostic groups of the DSM-IV axis I. The GAF scale can thus be used to assess global mental health and to monitor outcomes in clinical settings. However, a GAF culture bias was observed. This bias can probably be corrected with feedback and training. Psychiatric treatment in outpatient settings had a generally positive effect on patients’ global mental heath (ES = 0.65). The overall result when clinical significance methodology was used showed that 28.1% of the patients had recovered and a further 6.6% showed reliable improvement. Patients being treated with psychotherapeutically influenced methods showed a considerably better effect (ES = 1.00). There is a dose of sessions effect that is particularly marked for short treatment episodes. Thirteen sessions are required for 50% of the patients to show reliable improvement. The strongest influence on treatment outcome was whether the termination of a patient’s treatment was planned or unplanned. In conclusion: Clinical databases can be used to study the outcome of psychiatric services provided they a) include a large number of subjects representing an intention-to-treat perspective; b) the instruments used are clinically relevant and reliable; c) the raters contributing to the data base are motivated to decrease attrition; d) the database includes extensive data