Reliability and validity of the Persian version of the Kessler psychological distress scale among patients with type 2 diabetes

Introduction: Prevalence of depression in patients with diabetes is 2-3 times more than patients without diabetes. Hence, the aim of the current study was to evaluate the reliability and validity of Persian version of the 10-item Kessler Scale (K10) in assessment of mental health status among patients with type 2 diabetes in Ardabil, Northwest of Iran. Methods: This cross-sectional methodological study was conducted in Ardabil on a total of 70 patients with type 2 diabetes. K10 was translated into Persian by backward-forward method, and content validity was evaluated by a panel of experts in the field of psychiatry, psychology and epidemiology. Concurrent validity examined by the correlation between K10 and general health questionnaire-12 (GHQ-12). The reliability and stability evaluated by Cronbach¢s alpha and intraclass correlation coefficient (ICC) (test-retest method). The total score was computed from 10-items, which were classified into four categories (well, mild, moderate and severe). The analysis was performed using SPSS the level of significance was set at 0.05. Results: The total average content validity ratio (CVR) and content validity index (CVI) were 0.88 and 0.95; correlation between K10 and GHQ-12 was significant (r = 0.63, P < 0.001), hence, the content and concurrent validity of K10 Persian version was confirmed. Reliability was tested by Cronbach¢s alpha = 0.84 and ICC = 0.77, respectively. Conclusion: The Persian version of K10 is valid and reliable for evaluation of mental health status among patients with type 2 diabetes.