ABSTRACT
The aim of the study was to assess the validity and reliability of the SF-12 questionnaire in a sample of Iranian patients undergoing hemodialysis. One hundred and forty-four hemodialysis patients were included from dialysis centers in Zanjan, Iran, and were asked to complete the SF-12 and SF-36 questionnaires. An initial test-retest reliability evaluation was performed on a sample of 70 patients from the total group, with a retest interval of 14 days. Reliability was estimated by internal consistency and validity was assessed using known-group comparisons and construct validity on the patient group as a whole. A linear regression analysis was used to assess any variation in the physical component summary and mental component summary scores of the SF-36 with the respective component summary scores of the SF-12. In addition, the factor structure of the questionnaire was extracted by performing a confirmatory factor analysis. Cronbach alpha for physical and mental component summaries were 0.89 and 0.90, respectively. The SF-12 showed a good discriminatory ability between subgroups of patients based on demographic and clinical variables. The confirmatory factor analysis for the original two-factor structure showed a good fit index [chi2=23.30, degrees of freedom=13], goodness-of-fit index=0.96, and root mean squared error of approximation=0.079]. In general, the SF-12 has good psychometric properties and can be used as a shorter version of the SF-36 questionnaire in future studies involving Iranian patients undergoing hemodialysis
ABSTRACT
This study evaluated the health-related quality of life [HRQOL] in a sample of Iranian patients undergoing maintenance hemodialysis. The data were compared with the HRQOL for the Iranian general population. Two-hundred and fifty patients undergoing hemodialysis were included using a convenience sampling approach in a cross-sectional study. Data collection was performed using a Persian translation of the Short Form-36 questionnaire in combination with demographic and clinically related questions. The collected data were analyzed using a logistic regression model with physical and mental summary scales as dependent variables. The patients' mean Short Form-36 scores were significantly lower than those obtained for the general population for all scales. Patients with longer duration of being on hemodialysis, poor adherence to treatment, higher body mass index, and comorbidity diseases suffered from a poorer physical health. Poor mental health was associated with a lower level of education, longer duration of hemodialysis, lower economic status, a lower degree of knowledge on disease, and comorbidity diseases. This study affirms the fact that patients undergoing hemodialysis suffer from poor HRQOL. In comparison with data from other studies from Asian and European countries, this sample of Iranian patients on hemodialysis had a lower HRQOL, a discrepancy that might be due to differences in life style, socioeconomic status, the general level of education of the patients, as well as physician-patient communication