Translation and adaptation of the Zung Self- Rating Depression Scale for application in the bilingual Azerbaijani population

BACKGROUND: A self-reported Zung Self-Rating Depression Scale (ZSDS) is recognized as a reliable and valid measure for assessment of depressive symptoms, applicable cross-culturally. The aim of the study was to adapt ZSDS for application in the bilingual Azerbaijani population. METHODS: ZSDS was translated into Azerbaijani and Russian. Two pilot studies on small samples (n=30 and n=45) were conducted to improve the scale's acceptability. A readability study was conducted on a bigger sample of depressed subjects (n=55) and healthy controls (n=120). Chronbach's alpha for the total scale, item-test correlations, alpha if item deleted, and sensitivity and specificity at various cut-off levels were calculated. RESULTS: The drop-out rate was 83.3% at the first pilot study due to problems of comprehension of item 5 and culturally unacceptable wording of item 6. After rewording of the items drop-out reduced to 20%. On the reliability study Chronbach's alpha for the total scale was 0.8727, and item-test correlations for the most individual items were satisfactory. An optimal cut-off point was 45 points with sensitivity=90.91%, specificity=80.83%. CONCLUSIONS: Adaptation of the Zung Self-Reported Depression Scale improved cultural acceptability of the scale in the context of the Azerbaijani study population.