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

Abstract 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 Questionário de Restrição de Sódio 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 &lt;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.研究背景：钠摄入削减依从性低下或不依从，已被证实为心力衰竭（heart failure，HF）的主要诱发因素之一。饮食钠限制问卷（Dietary Sodium Restriction Questionnaire，DSRQ）可用于识别会干扰该推荐方案依从性的相关因素，但目前尚无用于界定该问卷依从性的截断值。 研究目的：明确巴西版饮食钠限制问卷（即Questionário de Restrição de Sódio na Dieta，QRSD）的满意依从性截断值。 研究方法：本研究为多中心研究，纳入接受门诊治疗的代偿性心力衰竭患者，以及因急性心力衰竭（失代偿状态）于急诊科就诊的患者。在截断值界定环节，通过比较两组患者的DSRQ评分开展分析；针对各分量表绘制受试者工作特征（Receiver Operating Characteristic，ROC）曲线，以确定依从性相关的最优灵敏度与特异度临界点，检验水准设定为5%。 研究结果：本研究共纳入206例代偿性心力衰竭患者与225例失代偿性心力衰竭患者。代偿性患者在所有分量表中的评分均显示出更高的依从性（所有p<0.05）。其中，态度与主观规范分量表满分为45分，评分≥40分提示满意依从性；感知行为控制分量表满分为20分，评分≤8分提示满意依从性；依赖行为控制分量表满分为15分，评分≤3分提示满意依从性。 研究结论：基于对上述两种临床场景下患者的评估，本研究明确了心力衰竭患者饮食钠削减满意依从性的截断值。文化背景相似的国家可采用该截断值，其他研究者亦可将本研究结果作为后续研究的参考依据。