Patient-assessed versus physician-assessed disease severity and outcome in patients with nonspecific pain associated with major depressive disorder

Abstract

Objectives: This post hoc analysis compared how patients and physicians estimate disease severity and global improvement during 8 weeks of treatment for major depressive disorder (MDD) with associated nonspecific pain. In addition, predictors of pain and depression were identified. Method: Data were derived from a double-blind, placebo-controlled, multicenter, European study (conducted from May 2005 to May 2006) in adult outpatients with MDD (DSM-IV criteria) and moderate pain not attributable to a diagnosed organic pain syndrome (Brief Pain Inventory-Short Form [BPI-SF] average pain score ≥ 3). Patients were randomly assigned to duloxetine 60 mg/day or placebo and treated for 8 weeks. Physicians were asked to rate severity of depression by using the Montgomery-Asberg Depression Rating Scale (MADRS) and the Clinical Global Impressions-Severity of Illness (CGI-S) and CGI-Improvement (CGI-I) scales. Patients were asked to assess pain using the BPI-SF, psychological symptomatology (9 domains including depression) with the Symptom Checklist-90-Revised (SCL-90-R), and overall improvement with the Patient Global Impression of Improvement (PGI-I). Multivariate linear regressions were performed as post hoc analyses to identify predictors of disease assessment at baseline and at the end of the study using a last-observation-carried-forward approach. Results: All SCL-90-R domains improved during the 8 weeks of treatment. At baseline, the MADRS was associated only with the SCL-90-R obsessive-compulsive score, while the SCL-90-R depression score was associated with the BPI-SF average pain score and with many SCL-90-R subscores. The global impression of improvement was rated higher by the physicians than by the patients. At the end of the study, CGI-I was significantly associated with a decrease in depression severity (MADRS; p