Journal of North Khorasan

Abstract Background and Objectives: The aim of the study was first to translate the Kidney Disease Quality of Life Short Form KDQOL-SF (version 1.3 (Questionnaire into Iranian and then to assess it in terms of validity and reliability on Iranian patients. Material & Methods: The questionnaire was first translated into Farsi by two independent translators, and then subsequently translated back into English. An initial test-retest reliability evaluation was performed on a sample of 20 patients from the total group (212 patients with end stage renal disease), over a ten day interval. Afterwards, reliability was estimated by internal consistency and validity was assessed using known group comparison and construct validity on the patient group as a whole. Finally, the factor structure of the questionnaire was extracted by performing exploratory factor analysis (EFA (. Results: All of the scales in the questionnaire showed good test–retest reliability(all above 0.7(. All of the items met the minimal criteria (i.e. 0.7 (for internal consistency and Cronbach's α ranged from 0.73 to 0.93. To test construct validity, we examined correlations of the kidney disease targeted scales and overall health rating scale. The majority of items correlated significantly with the overall health rating. Furthermore, results from a discriminate validity evaluation showed that the questionnaire could be used to discriminate between subgroups of the patients. Finally, a principal component analysis of the disease specific scales indicated that this part of the questionnaire could be summarized into a two-factor structure (disease burden and patient satisfaction (that jointly accounted for 63 % of the variance. Conclusion: The Iranian version of the KDQOL-SF questionnaire is both highly reliable and valid for use with Iranian ESRD patients.