Validity and reliability of the dietary sodium restriction questionnaire in patients with hypertension.

The study aimed to evaluate the reliability and the validity of the dietary sodium restriction questionnaire (DSRQ) in patients with hypertension receiving outpatient treatment at a tertiary care university hospital in Southern Brazil. This instrument is composed of three subscales: attitude, subjective norm and perceived behavioral control. A total of 104 patients were included. They were 63.3±8.9 years old and 75% were females. Cronbach's alpha coefficient for the subscales of attitude, subjective norm and perceived behavioral control were 0.75, 0.37 and 0.82, respectively. The PCA with the extraction of three factors explained a total of 53.5% of the variance. The data suggest that the 15-item DSRQ is reliable and has internal consistency of its construct to measure the barriers and the attitudes of hypertensive patients related to dietary sodium restriction and may be useful to improve blood pressure control.