Psychometric properties of the Swedish version of the Outcome Questionnaire-45 as administered by automated technique in a large sample of mental ill-health patients in Primary Health Care

Background and Objectives: Mental health problems are common in Primary Health care and clinicians require valid and reliable instruments to make good treatment plans for these patients. The Outcome Questionnaire-45 (OQ-45) was developed by Lambert and colleagues in order to help improve outcomes of treatment. The aims of this study were to examine the psychometric properties of the Swedish version of OQ-45 when administered by an automated technique and to evaluate if the OQ-45 uniquely could contribute to the description of the patients’ difficulties and needs beyond demographic characteristics and other instruments. Methods: The study comprised 816 patients with mental ill-health taking part in a large randomized controlled trial, Regassa. The OQ-45 data were collected by Interactive Voice Response IVR, a computerized, automated telephone technique. The OQ-45 consists of 45 items summarized in a total score and in three subscales; Symptoms of distress, SD, Interpersonal relations, IR, and Social role functioning, SR. Depression was measured by MADRS and health-related quality of life by EQ-5D. Results: The OQ-45 total score showed good psychometric properties, but there was little support for its three factor structure. The OQ-45 significantly predicted level of depression and health-related quality of life in patients. Conclusions: The OQ-45 contributed uniquely to the description of the patients´ problems. The results indicate that the total score of the Swedish version of OQ-45 can be valuable to use for clinicians in the field