Determinants and the Role of Self-Efficacy in a Sodium-Reduction Trial in Hemodialysis Patients

Abstract

This study was to assess the impact of baseline dietary self-efficacy on the effect of a dietary intervention to reduce sodium intake in patients undergoing hemodialysis (HD) and to identify determinants of low dietary self-efficacy. This is a post hoc analysis of the BalanceWise study, a randomized controlled trial that aimed to reduce dietary sodium intake in HD patients recruited from 17 dialysis centers in Pennsylvania. The main outcome measures include dietary self-efficacy and reported dietary sodium density. Analysis of variance with post hoc group-wise comparison was used to examine the effect of baseline dietary self-efficacy on changes in reported sodium density in the intervention and control groups at 8 and 16 weeks. Chi-square test, independent t tests, or Wilcoxon rank-sum tests were used to identify determinants of low dietary self-efficacy. The interaction between dietary self-efficacy and the impact of the intervention on changes in reported dietary sodium density approached significance at 8 and 16 weeks (P interaction = 0.051 and 0.06, respectively). Younger age and perceived income inadequacy were significantly associated with low self-efficacy in patients undergoing HD. The benefits of dietary interventions designed to improve self-efficacy may differ by the baseline self-efficacy status. This may be particularly important for HD patients who are younger and report inadequate income as they had lower dietary self-efficacy.