ABC | Volume 112, Nº2, February 2019

Original Article d’Almeida et al Cut-point for Dietary Sodium Restriction Questionnaire Arq Bras Cardiol. 2019; 112(2):165-170 Figure 1 – ROC curves for all three DSRQ subscales. 1.0 1.0 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 0.0 1.0 0.8 0.6 0.4 0.2 0.0 0.0 Sensitivity Sensitivity Sensitivity 1 – Specificity ROC Curve ROC Curve ROC Curve 1 – Specificity 1 – Specificity 1.0 0.8 0.6 0.4 0.2 0.0 1.0 0.8 0.6 0.4 0.2 0.0 1.0 0.8 0.6 0.4 0.2 0.0 Table 2 – Scores of the Dietary Sodium Restriction Questionnaire subscales for compensated and decompensated patients and for categories of functional class Attitude and subjective norm Perceived behavioral control Dependent behavior Situation Compensated 42.6 ± 4.0 8.4 ± 4.1 5.2 ± 3.0 Decompensated 38.5 ± 6.3 10.9 ± 4.2 5.5 ± 3.0 p value < 0.001 < 0.001 0.399 Functional class I x II 41.6 ± 5.1 8.8 ± 4.4 5.0 ± 2.8 III x III 39.3 ± 6.1 10.6 ± 4.2 5.6 ± 3.2 p value < 0.001 < 0.001 0.038 *Continuous variables described as mean ± standard deviation Table 3 – Cut-point for adherence established to the Dietary Sodium Restriction Questionnaire subscales Subscales Scores (min - max) Cut-point (adherence) Sensitivity (%) Specificity (%) Attitude and subjective norm 9 - 45 ≥40 53.8 83.5 Perceived behavior control 4 - 20 ≤8 68.0 58.3 Dependent behavior control 3 - 15 ≤3 60.9 51.0 differences between the studied populations, it is recommended that, in the Brazilian population, theQRSD be applied by means of interviews, by trained investigators. In addition, because each subscale relates to a particular construct, we sought to identify different cut-points for each of them. High scores observed in the subscale of attitudes and subjective norm contributed to raising the cut-point (≥ 40, a total of 45 points) and indicated that patients are aware of the importance of adhering to sodium reduction, and can identify signs and symptoms associated with excessive intake, as well as benefits related to the reduction. However, as described in the literature, 7,24,25 knowledge alone does not seem to be sufficient to ensure compliance, to which other skills are required, such as motivation and willpower. 21 Accordingly, incorporating this measure into the routine remains a major challenge for patients. On the same subscale, the last three questions that denote adherence are influenced by the opinion of people considered important by patients (spouse, family members, physicians and other health professionals). The inclusion of family members in the treatment of patients with HF appears to be a crucial point and is gaining more space as a strategy for self-care, with positive results in the reduction of sodium intake by these patients. 21,22 168