Abstract
Objectives
Dietary sodium restriction guidelines are controversial due to a lack of studies assessing their effect on heart failure outcomes. An important aspect of this problem is the effectiveness of behavioral nutrition interventions to reduce patients’ sodium intake. We systematically reviewed randomized controlled trials (RCTs) of sodium restricted diets and descriptive studies relating mediators of behavior to successful adherence to sodium restricted diets in patients with heart failure.
Methods
We queried PubMed, CINAHL, and Cochrane databases with relevant search terms for studies published in English January 2000-December 2018. Included were RCTs of interventions for heart failure patients, with sodium restriction as a primary or secondary outcome, and quantitative and qualitative descriptive studies of adherence to sodium restricted diets. Included studies may or may not have reported clinical outcomes (health events, quality of life, etc.). Reviewers noted setting, methods, and outcomes as well as theoretical mediators of dietary behavior change in included studies. We then compared behavioral mediators addressed by the RCTs and behavioral mediators identified in the descriptive studies.
Results
Of 638 studies identified, 445 were excluded by title. 2 reviewers assessed 60 abstracts and included 36 studies in this analysis: 10 RCTs and 26 descriptive studies. 6 of 10 intervention RCTs were successful, but no interventions achieved the recommended 1500 mg/day sodium intake (mean for all studies 3271 mg/day). Interventions that reduced sodium intake were behaviorally focused, were delivered by an RN and/or RD, and included individual feedback and counseling. RCTs intervened only through knowledge, skills, and social support. Behavioral mediators identified in descriptive studies included perceived risk, perceived benefits, outcome expectations, cultural norms, social norms, social support, taste preferences, determinism, self-efficacy, knowledge, skills, and habits. These were not included in the RCTs, which signifies a mismatch between evidence-based moderators of behavior and intervention designs.
Conclusions
RCTs have been unable to achieve the recommended goal of 1500 mg/day of sodium. More effective interventions should consider evidence-based mediators, rather than focusing on knowledge and skills.
Funding Sources
Dr. Burgermaster received funding from NHLBI T32 training grant.
Dietary Sodium Restriction for Heart Failure: A Systematic Review of Intervention Outcomes and Behavioral Determinants
