ABSTRACT
OBJECTIVE: To assess the validity, responsiveness, and test-retest reliability of DISCs (Depression Intensity Scale Circles) as a simple screening tool for depression in patients with cognitive or communicative deficits following acquired brain injury. DESIGN: Cohort analysis of consecutive patients entered into an integrated care pathway for screening and management of depression in the context of rehabilitation. SETTING: Regional neurological rehabilitation service in the UK. PARTICIPANTS: 114 patients with complex disabilities caused by acquired brain injury (mean (SD) age, 42.8 (14.5) years). MAIN OUTCOME MEASURES: DISCs (a graphic rating scale depicting six circles with increasing proportion of dark shading), Numbered Graphic Rating Scale (NGRS), Yale single question ("Do you often feel sad or depressed"), Beck Depression Inventory-II (BDI-II), DSM-IV criteria for depression. RESULTS: At initial assessment the DISCs correlated with total BDI-II scores (Spearman rho = 0.66, p < 0.001), NGRS (rho = 0.87, p<0.001), and DSM-IV (rho = 0.59, p<0.001). A DISCs score > or =2 identified depression (major or minor) according to DSM-IV criteria with 60% sensitivity, 87% specificity, 75% positive predictive value, and 77% negative predictive value. Test-retest reliability after 24 hours (n = 66) showed "excellent" level of agreement (weighted kappa = 0.84). In 45 patients who received intervention for depression, the DISCs showed a significant change in response to treatment (Wilcoxon; p<0.001). CONCLUSIONS: DISCs had acceptable convergent validity, reliability, and responsiveness as a simple graded tool for screening and assessment of depression in patients with complex disabilities following acquired brain injury. It warrants further investigation in patients with more profound language and cognitive deficits for which it is primarily intended.
