Rasch analysis of the scoring scheme of the HADS Depression subscale in Chinese stroke patients.

The Hospital Anxiety and Depression Scale (HADS) is a widely used screening instrument for depression in medically ill patients. The purpose of this study was to examine the optimal scoring scheme, unidimensionality and item fit of the depression subscale of the HADS (HADS-D) in stroke survivors. A research assistant administered the HADS-D to 100 Chinese patients with acute stroke who were consecutively admitted to a general hospital. A psychiatrist, who was blind to the HADS-D scores, administered the SCID-DSM-III-R to all 100 patients and made a DSM-IV diagnosis of depression, which served as the benchmark for judging the performance of the HADS-D in screening for depression. Rasch analysis has shown that the HADS-D was unidimensional; low endorsements for the higher coded alternative response categories were found in the sample. In clinical samples with a low frequency of depression, the scoring categories of the HADS-D may be reduced.