Evaluating the Psychometric Properties and Responsiveness to Change of 3 Depression Measures in a Sample of Persons With Traumatic Spinal Cord Injury and Major Depressive Disorder

ObjectivesTo compare the measurement properties and responsiveness to change of the Patient Health Questionnaire-9 (PHQ-9), the Hopkins Symptom Checklist-20 (HSCL-20), and the Hamilton Depression Rating Scale (HAM-D) in people with spinal cord injury (SCI) diagnosed with major depressive disorder (MDD).DesignSecondary analysis of depression symptoms measured at 6 occasions over 12 weeks as part of a randomized controlled trial of venlafaxine XR for MDD in persons with SCI.SettingOutpatient and community settings.ParticipantsIndividuals (N=133) consented and completed the drug trial. Eligibility criteria were age at least 18 years, traumatic SCI, and diagnosis of MDD.InterventionsVenlafaxine XR.Main Outcome MeasuresPatients completed the PHQ-9 and the HSCL-20 depression scales; clinical investigators completed the HAM-D and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition (DSM-IV) Dissociative Disorders, which was used as a diagnostic criterion measure.ResultsAll 3 instruments were improved with rating scale analysis. The HSCL-20 and the HAM-D contained items that misfit the underlying construct and that correlated weakly with the total scores. Removing these items improved the internal consistency, with floor effects increasing slightly. The HAM-D correlated most strongly with Structured Clinical Interview for DSM-IV Dissociative Disorders diagnoses. Improvement in depression was similar on all outcome measures in both treatment and control groups.ConclusionsThe psychometric properties of the revised depression instruments are more than adequate for routine use in adults with SCI and are responsive to clinical improvement. The PHQ-9 is the simplest instrument with measurement properties as good as or better than those of the other instruments and required the fewest modifications.