Validation of the Hospital Anxiety and Depression Scale in Patients With Acute Low Back Pain

The Hospital Anxiety and Depression Scale (HADS) is a self-report instrument used to evaluate depression and anxiety in clinical research. The HADS has advantages over other assessments of anxiety and depression; it is efficient in assessing both anxiety and depression with a total of 14 items, and it was originally developed on a general medical rather than psychiatric sample. However, the HADS has not been evaluated specifically for use in clinical trials of acute pain. Validation analyses were conducted on data from a randomized, double-blind, parallel-group study of tapentadol immediate release vs oxycodone immediate release for acute low back pain (N = 666). Analyses of psychometric properties, internal consistency, convergent validity, assessments of bias, and confirmatory factor analysis were conducted on pretreatment data. Additional analyses were performed to test the responsiveness and predictive validity of the HADS. Both the Anxiety and Depression subscales 1) showed good psychometric properties, 2) had high internal consistency, 3) displayed good convergent validity, 4) had no unexpected biases, 5) fit the a priori factor structure, and 6) were highly sensitive to changes as a result of analgesic treatment. We conclude that the HADS is a valid instrument for efficient, low-burden assessment of anxiety and depression in clinical trials with an acute low back pain population.