Potential contributing factors to noncompliance with dietary sodium restriction in patients with heart failure

Background Although sodium restriction is considered essential in the management of patients with chronic heart failure (CHF) there are no data available regarding patients awareness of and ability to comply with the sodium restriction guideline. Methods Between May 1999 and August 2000, 50 patients referred to the Parkland Memorial Hospital CHF clinic were assessed by a registered dietitian for (1) awareness of the sodium restriction guideline, (2) ability to read the sodium content from a Nutrition Facts label, and (3) ability to sort 12 food containers, all bearing a Nutrition Facts label, into high- and low-sodium groups. A global measure of dietary sodium knowledge was calculated (''sodium knowledge score,'' range 0-10). These tests were repeated after the patient completed one or more educational sessions (mean 2.8 +/- 1.5) with the dietitian. Results The proportion of patients aware of the sodium restriction guideline was 14% at baseline and 42% at follow-up (P <.01). The proportion of patients able to read the sodium content from the Nutrition Facts label was 58% at baseline and 92% at follow-up (P <.01). The sodium knowledge score was 3.8 +/- 3.4 at baseline and 5.8 +/- 3.2 at follow-up, (P <.01). The proportion of subjects who achieved a perfect sodium knowledge score of 10 was 8% at baseline and 26% at follow-up (P <.05). The number of food containers sorted accurately was 10.6 +/- 1.5 at baseline and 11.3 +/- 1.1 at follow-up, P = .09. Conclusions On referral to a specialty CHF clinic, many patients had severe deficiencies in their knowledge base regarding dietary sodium intake that would preclude compliance with the sodium restriction guideline. Directed education focusing on sodium intake corrected many of these deficiencies.