Validation of the aphasic depression rating scale

Abstract

Background and Purpose - The Aphasic Depression Rating Scale (ADRS) was developed to detect and measure depression in aphasic patients during the subacute stage of stroke. Methods - Six experts selected an initial sampling of behavioral items from existing depression rating scales. Stroke patients (aphasic and nonaphasic) were assessed with these items by the rehabilitation staff, with the Hamilton Depression Rating Scale (HDRS) for nonaphasic patients only, by a psychiatrist, and by the rehabilitation staff with Visual Analog Scales (VAS). A second item selection was conducted after a regression algorithm was run including VAS as independent variables (criterion validity) and after their factorial structure was analyzed with a principal component analysis (factorial validity). The construct validity was evaluated with respect to the other depression assessments. A threshold for the diagnosis of depression was computed with respect to the psychiatrist's diagnosis. Interrater and test-retest reliability were assessed in 2 additional groups of aphasic patients. Results - Eighty patients participated in the study (59 aphasic), Fifteen behavioral items from existing depression rating scales were selected, and 9 were retained after the validation process. ADRS correlated highly with VAS and HDRS (r=0.60 to 0.78, P=10-4 to 10-6). With respect to the psychiatrist's diagnosis, the sensitivity and specificity of ADRS were 0.83 and 0.71, respectively, when the threshold was set at 9/32. Its factorial structure was comparable to HDRS structure. Interrater and test-retest reliability were high (average κ coefficient of the 9 items=0.69). Conclusions - ADRS is a valid, reliable, sensitive, and specific tool for the evaluation of depression in aphasic patients during the stroke subacute phase.