Avoidance of dietary sodium — a simple questionnaire

Patients who are advised to reduce their sodium intake need intensive counselling and regular feedback on their progress. Urinary tests can indicate a high sodium intake, but the dietary source remains unknown until the patient has answered detailed questions. We have developed a sodium‐intake check‐list for this purpose and have investigated whether it is comprehensive enough to replace the urinary test. The most heavily‐salted foods in the typical Western diet are listed in 21 questions, which are to be answered in relation to the previous three days' intake with a frequency rating of “zero” to “eight or more”; the check‐list score is the sum of the scores for all 21 items. For 190 college students who were eating their regular diet, the scores were distributed normally and internally were reliable (Cronbach coefficient α = 0.75). They were significantly different ( P < 0.001) from the scores of the 40 persons who were attending a low‐sodium advisory service. The range of the urinary sodium excretion rate for 39 persons in the latter group was 9‐181 mmol/24 h. The correlation between the urinary sodium excretion results and those of the check‐list was r = 0.701, which is an acceptable figure considering that the urine excretion data were, for practical reasons, derived from a single 24‐h sample. As the absolute sodium excretion is itself only an estimate of dietary behaviour, we consider that this simple questionnaire, as based on a three‐day recall, is useful in the management of patients who are ingesting “salt‐free” diets, both as an adjunct and as an alternative to urinary testing in routine clinical use.