Proposing a new stroke-specific screening tool for depression: Examination of construct validity and reliability

Objectives The optimal tool for identifying depression after stroke is yet to be identified. In the present study, we propose a new context-specific screening tool for PSD and examined its construct validity and reliability within existing data on recent stroke survivors. Methods We assessed baseline data being collected as part of an intervention to improve one-year blood pressure control among recent (≤one month) stroke survivors. Depression was measured using the Hospital Anxiety and Depression Scale (HADS-D). We also independently administered the 26-items Health Related Quality of Life in Stroke Patients (HRQOLISP-26), a stroke-specific measure developed from a large cross-cultural sample. Using standard protocol, we identified 6 psychoemotional-domain items of the HRQOLISP-26 fitting a single dimensional model with phenomenological and conceptual overlap with the depression framework in the 10th revision of the International Classification of Diseases (ICD-10). We examined construct validity by comparing HRQOLISP-E with the HADS-D, and known group validity by comparing with age, gender, and stroke severity using both the Pearson product moment coefficient and multivariate regression analyses. Internal consistency and split-half reliability were also determined. Results Each HRQOLISP-E item (r = -0.40 to -0.53, all p < 0.001), as well as the total HRQOLISP-E score (-0.53, p < 0.001) showed significant correlation with the HADS-D. The HRQOLISP-E scores also correlated significantly with age and stroke severity. Depression assessed using the HRQOLIPS-E was independently associated with older age and stroke severity. All HRQOLISP-E items scale correlations were> 0.8 (0.81-0.93) compared with 0.56-0.68 for the HADS-D (Cronbach's alpha =0.939, versus 0.742 for the HADS-D, Split-half reliability = 0.899, versus 0.739 for HADS-D). Conclusion These results provides preliminary support for further development of the HRQOLISP-E as a context-specific screening tool for PSD through an investigation comparing the proposed measure against a referent-standard clinical diagnostic criteria such as the ICD 10 or Diagnostic and Statistical Manual of Fourth Edition of the Diagnostic and Statistical Manual of Mental Disorders.