Quality of life in thalassemia major: Reliability and validity of the Persian version of the SF-36 questionnaire

Aims: The objective of this study was to determine the reliability and validity of the eight-item Short Form Health Survey (SF-36) questionnaire translated into Persian for use in Iranian patients with thalassemia major.
Materials and Methods: Using a standard "forward-backward" translation procedure, the English language version of the questionnaire was translated into Persian. Two hundred patients with thalassemia major following up at the Thalassemia Center, Dastgheib Hospital, Shiraz, Iran, were enrolled in this study.
Statistical Analysis: The reliability and internal consistency of the questionnaire were assessed by Cronbach′s alpha coefficient and Spearman′s correlation, respectively. Validity was assessed using convergent and discriminant validity.
Results: The mean age of 200 subjects enrolled in the study was 19.81+/-4.07 years. Reliability analysis showed satisfactory results (Cronbach′s a coefficient = 0.915). The factor analysis showed that all items were in the same groups as previous studies with the exception of role emotional and general health that had been substituted. Most of the patients were in lower range of normal for both mental and physical summary status.
Conclusions: The study finding showed that the Persian version of SF-36 questionnaire has a good structural characteristic and is a reliable and valid instrument for measuring the quality of life of patients with thalassemia major.