Patient-Rated Outcome Assessment With the German Version of the Outcome Questionnaire 45 in People With Severe Mental Illness

Abstract

The purpose of this study was to assess the feasibility and psychometric properties of the German version of the Outcome Questionnaire (Ergebnisfragebogen; EB-45) in people with severe mental illness (N = 294). Reliability and sensitivity to change were assessed. Convergent validity was examined through correlations with the measures Health of the Nation Outcome Scales (HoNOS-D) and Global Assessment of Functioning (GAF), and predictive validity through correlation with length of inpatient stay. The EB-45 showed good reliability and sensitivity to change, as well as good internal consistency for the total score and the subscale “symptom distress.” The EB-45 was found to be acceptable and feasible for use within inpatient psychiatric settings. Also predictive validity was good. However, psychometric properties of the subscales “interpersonal relations” and “social role” were equivocal. Thus, interpreting subscale scores only is not advisable. Also low convergent validity is a concern. Taken together, the EB-45 can be recommended for outcome assessment in a wide range of mental health service settings including inpatient psychiatric services. However, treatment planning and evaluation of effectiveness of services for people with severe mental illness should not be based on EB-45 data alone.