Early detection of Post Stroke Depression: psychometric properties of the Signs of Depression Scale – Rehabilitation centre.

Abstract

Background: Observational tools for nurses could be useful to improve the recognition of depressive symptoms in stroke patients. The Signs of Depression Scale (SODS) is probably the most promising instrument in daily nursing care. Aim and research question(s): Early recognition and treatment of depression could contribute to nurses quality of care and patients’ rehabilitation outcomes. This study is a validation of the Dutch four-point rated SODS (SODS-R) on internal consistency, inter-rater reliability, test-retest reliability, criterion validity, construct validity, diagnostic accuracy and feasibility. Method: An observational, cross-sectional study was conducted in an inpatient ward of a rehabilitation centre. Participants were approached according a census approach. The 9-item Patients Health Questionnaire (PHQ-9) was used as a reference test for the SODS-R in criterion validity and diagnostic accuracy. The Barthel Index (BI) was used as an external validator for construct validity of the SODS-R. Feasibility was evaluated with a questionnaire on criteria of practicality. Results: The SODS-R was administered 38 times by 18 nurses in 13 patients. The PHQ-9 was administered 12 times through patients and 12 times through relatives. Internal consistency (Cronbach’s α=0.805) and test-retest reliability (ICC=0.836) of the SODS-R were good and inter-rater reliability showed a moderate correlation (ICC=0.509). The SODS-R showed a low criterion-validity against the PHQ-9 (r=0.559). The optimum cut-point was ≥3 (sensitivity=66.67%, specificity=100%, positive predictive value=100%, negative predictive value=90%). Construct validity of the SODS-R against functional impairment with the BI was moderate (r=-0.622). Feasibility was good except for the response format, which was subject to interpretations. Conclusion: This study showed slight indications for the use of SODS-R by nurses in rehabilitation centres. Recommendations: Further research is recommended on the psychometric properties of the SODS-R in a larger sample of stroke patients. Regardless this study, screening for PSD should be part of routine care.