A Validation of Dietary Self-Efficacy Questionnaire in Hemodialysis Patients

ABSTRACT

BACKGROUND: This study was performed to develop a dietary self-efficacy questionnaire and to determine how dietary self-efficacy is related to selected biochemical markers and health-related quality of life in hemodialysis patients. METHODS: Participants included 172 patients who had been participating in a dialysis program for at least 6 months at two teaching hospitals. A questionnaire was used to assess socio-demographic factors, dialysis-related factors, dietary self-efficacy, and kidney disease quality of life (KDQOL). Serum levels of potassium and phosphorus and interdialytic weight gain were also measured. RESULTS: The internal reliability of dietary self-efficacy was 0.944 (Cronbach's alpha). Principal component analysis resulted in two factors, situational self-efficacy of compliance with dietary guidelines and self-efficacy of food choice. The correlation analysis showed a significant association between situational self-efficacy of compliance with dietary guidelines and serum potassium and KIDQOL. The average scores of situational self-efficacy of compliance with dietary guidelines and self-efficacy of food choice in the participants were 3.52+/-0.72 and 3.61+/-0.71 respectively. Multiple linear regression analysis showed that the situational self-efficacy of compliance with dietary guidelines was significantly associated with serum potassium level and KDQOL and self-efficacy of food choice was significantly associated with KDQOL. CONCLUSIONS: Based on our results, the developed dietary self-efficacy questionnaire may be a suitable survey tool for hemodialysis patients, which can play a role in predicting clinical indicators of patient and health-related quality of life. We recommend further research into clarifying whether the positive effects of increased dietary self-efficacy is maintained in long-term dialysis patients.