(874): Validity study of the depression anxiety stress scales in a sample of chronic pain patients

Abstract

In the search for a reliable, efficient, clinical scale for monitoring the severity of mood disorders and their change over time in patients with chronic nonmalignant pain, we compared 3 commonly used scales to determine if the Depression Anxiety Stress Scales (DASS) would compare favorably with the more commonly sited Profile of Mood States (POMS), and Beck Depression Inventory (BDI). The DASS has 42 items and results in 3 scales: Depression, Anxiety and Stress. The POMS has 65 items resulting in 6 scales including: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Vigor-Activity, Fatigue-Inertia, and Confusion-Bewilderment. The BDI has 21 items resulting in a single depression score. Internal validity and degree of correlation were obtained using the DASS, Profile of Mood States (POMS), and Beck Depression Inventory (BDI) with a sample of 190 patients seeking treatment within a chronic pain rehabilitation program. High internal consistencies (0.72 to 0.95) were obtained at the subscale level for each of the instruments. Cronbach’s alpha for the DASS Depression scale was 0.96, for the BDI, 0.85, and for the POMS Depression scale, 0.95. The DASS Depression score was highly associated with both the BDI score (r=.81, p<.001) and the POMS Depression score (r=0.84, p<.001), demonstrating good convergent validity. The DASS Anxiety scale correlated with the POMS Tension scale at 0.71 and DASS Stress scale correlated with the POMS Tension at 0.72. The Vigor subscale from the POMS correlated negatively with the DASS Depression scale (r=-0.32, p<.001) and the DASS Anxiety scale (r=-0.16, p<0.04), to provide evidence of discriminant validity. Overall, the DASS appears to be a sound instrument for assessing emotional distress in the chronic pain population, while avoiding the confluence of health concerns and symptoms of depression.