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.