Adherence to a low-sodium diet in patients with heart failure is best when family members also follow the diet: a multicenter observational study.
BACKGROUND
Adherence to a low-sodium diet (LSD) is difficult without continuous support from spouses or family members. Whether having a family member follow an LSD improves patient adherence has not been tested objectively.


OBJECTIVE
The aim of this study was to examine the effect of family adherence to an LSD on patient adherence to an LSD and to examine whether this effect differed by relationship status and living arrangement.


METHODS
In this secondary data analysis, we analyzed data from 379 outpatients with heart failure who had objective evidence of adherence to an LSD (ie, a 24-hour urinary sodium excretion). The t test, analysis of variance, and logistic regressions were used to compare levels of adherence among groups that were categorized by family adherence to an LSD, relationship status, and living arrangement with family member and to predict the likelihood of being adherent to an LSD (24-hour urinary sodium excretion <3000 mg) by the groups.


RESULTS
Compared with patients whose family did not follow an LSD, patients whose family member followed an LSD had lower average urinary sodium excretion (3651 vs 4280 mg; P = .003) and were 1.6 times more likely to be adherent to an LSD (95% confidence interval, 1.03-2.4; P = .035). Patients whose spouses followed the LSD had lower sodium excretion than did patients whose spouses did not follow the LSD (3730 vs 4534 mg; P = .012). Patients whose nonspousal family member followed an LSD were 4 times more likely to be adherent than were patients whose spousal member did not follow an LSD (odds ratio, 3.94; 95% confidence interval, 1.81-8.58; P = .001).


CONCLUSIONS
Living with a spouse or other family member improved patient adherence to LSD only when the spouse or family member also followed the LSD. These results suggest that interventions aimed at improving LSD adherence should target patient and family member dyads to encourage family members to follow the LSD with patients.