Psychometric evaluation of the Depression Anxiety Stress Scale 8 among women with chronic non-cancer pelvic pain

Abstract

Psychiatric comorbidity and abusive experiences in chronic pelvic pain (CPP) conditions may prolong disease course. This study investigated the psychometrics of the Depression Anxiety Stress Scale 8 (DASS-8) among women with CPP (N = 214, mean age = 33.3 ± 12.4 years). The DASS-8 expressed excellent fit, invariance across age groups and menopausal status, good know-group validity (differentiating women with psychiatric comorbidity from those without comorbidity: U = 2018.0, p = 0.001), discriminant validity (HTMT ratios < 0.85), excellent reliability (alpha = 0.90), adequate predictive and convergent validity indicated by strong correlation with the DASS-21 (r = 0.94) and high values of item-total correlations (r = 0.884 to 0.893). In two-step cluster analysis, the DASS-8 classified women into low- and high-distress clusters (n = 141 and 73), with significantly higher levels of distress, pain severity and duration, and physical symptoms in cluster 2. The DASS-8 positively correlated with pain severity/duration, subjective symptoms of depression/anxiety, experiences of sexual assault, fatigue, headache severity, and collateral physical symptoms (e.g., dizziness, bloating, fatigue etc.) at the same level expressed by the parent scale and the DASS-12, or even greater. Accordingly, distress may represent a target for early identification of psychiatric comorbidity, CPP severity, experiences of sexual assault, and collateral physical complaints. Therefore, the DASS-8 is a useful brief measure, which may detect mental distress symptoms among women with CPP.