Patient-Assessed Versus Physician-Assessed Disease Severity and Outcome in Patients With Nonspecific Pain Associated With Major Depressive Disorder

Abstract

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. 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. 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 < .0001), younger age (p = .0005), and a decrease of the SCL-90-R interpersonal sensitivity score (p = .0359), but not with BPI-SF average pain. In contrast, patient-rated PGI-I was significantly associated with the SCL-90-R depressive domain (p < .0001), BPI-SF average pain (p = .0003), and the SCL-90-R anxiety domain (p = .0041) scores. In patients with MDD associated with at least moderate nonspecific pain, physicians consider mainly the change in depressive symptoms as measured by MADRS in their CGI-I ratings, while patients also consider pain, depression, and anxiety in their PGI-I ratings. When treating depression and assessing treatment outcome, a broad spectrum of symptoms needs to be monitored. clinicaltrials.gov Identifier: NCT00191919.