Cut-Point for Satisfactory Adherence of the Dietary Sodium Restriction Questionnaire for Patients with Heart Failure

Background: The low or non-adherence to reduction of sodium intake has been identified as one of the main precipitating factors of heart failure (HF). The Dietary Sodium Restriction Questionnaire (DSRQ) identifies factors that can interfere with adherence to this recommendation. However, there is still no cut-point to define adherence for this questionnaire. Objectives: To identify the cut-point for satisfactory adherence to the Brazilian version of the DSRQ, (the Questionario de Restricao de Sodio na Dieta, QRSD). Methods: Multicenter study. Patients with HF in outpatient treatment (compensated) and those treated in emergency departments due to acute HF (decompensated) were included. For the cut-point definition, the DSRQ scores were compared between groups. A ROC curve was constructed for each subscale to determine the best point of sensitivity and specificity regarding adherence. A 5% significance level was adopted. Results: A total of 206 compensated patients and 225 decompensated were included. Compensated patients exhibited scores that showed higher adhesion in all subscales (all p <0.05). Scores >= 40 points of a total of 45 for the subscale of Attitude and Subjective Norm; scores <= eight of a total of 20 for Perceived Behavioral Control; and <= three of a total of 15 for Dependent Behavior Control were indicative of satisfactory adherence. Conclusions: Based on the evaluation of patients in these two scenarios, it was possible to determine the cut-point for satisfactory adherence to the reduction of sodium in the diet of patients with HF. Countries with similar culture could use this cut-point, as other researchers could also use the results as a reference for further studies.