Psychometric properties of the persian version of the diabetes self-management questionnaire for patients with Type 2 diabetes in Iran

Background: Diabetes self-management questionnaire (DSMQ) is among the relatively new tools with comprehensive structure measuring various dimensions of self-care behaviors in diabetic patients. This study was carried out to evaluate psychometric properties of Persian version of DSMQ. Methods: A cross-sectional study was carried out from January to March 2017 among patients with type 2 diabetes mellitus (T2DM) referred to urban health centers, in Kerman, southeastern Iran. Data were collected from 589 patients using DSMQ. The DSMQ was translated into Persian by forward and backward translation method. Cronbach's alpha method and intraclass correlation coefficient (ICC) were used to measure internal consistency and test-retest reliability, respectively. In addition, construct validity was assessed by confirmatory factor analysis and exploratory factor analysis (EFA). Results: The sum-scale Cronbach's alpha of DSMQ was equal to 0.82 for 30 participants. The mean inter-item correlation and mean item-total correlation of "Sum Scale" (SS) were equal to 0.21 (standard deviation (SD) = 0.22) and 0.53 (SD = 0.19), respectively. All items had item-total correlations higher than 0.30 except items 7, 11, and 15. For "SS," ICC was obtained as 0.93. EFA revealed a four-factor model accounting for 62.5% of the total variance. All indices were acceptable for the modified DSMQ with four factors (chi(2) = 134.33, degrees of freedom = 89, P = 0.001, comparative fit index = 0.97, root mean square error of approximation = 0.044, Tucker-Lewis index = 0.96, and normal fit index = 0.92). Conclusions: The Persian version of DSMQ was found to have acceptable reliability and validity for assessing self-management among patients with T2DM.