Nutritional knowledge in hemodialysis patients and nurses: focus on phosphorus.

OBJECTIVE To assess the knowledge of adult hemodialysis patients and nurses working in dialysis units, specifically with regard to knowledge of phosphorus and other nutrients related to dietary management of end-stage renal disease. DESIGN Cross-sectional cohort study. SETTING Hemodialysis unit. SUBJECTS One hundred ninety-one hemodialysis patients and 105 dialysis nurses, as well as 86 control hospital employees who are not health professionals. INTERVENTION Nutritional knowledge was assessed by a 25-item chronic kidney disease knowledge assessment tool for nutrition, which includes 15 questions on phosphorus and 10 questions on protein, sodium, and potassium knowledge. RESULTS The scores obtained by patients were much lower than those of nurses (11.6 ± 3.9 vs. 16.0 ± 2.2, P < .001) but slightly higher than those of controls (10.6 ± 3.2, P < .05). Patients with phosphorus serum level >5.5 mg/dL showed chronic kidney disease knowledge assessment tool for nutrition scores similar to those of patients with a serum phosphorus level <5.5 mg/dL. The prevalence of right answers to questions regarding knowledge of phosphorus was lower than that regarding knowledge of the other nutrients, both for patients (38.4% ± 17.8% vs. 57.3% ± 19.9%, P < .001) and nurses (55.6% ± 11.1% vs. 74.8% ± 11.7%, P < .001) as well as for controls (30.7% ± 14.5% vs. 60.1% ± 17.4%, P < .001). CONCLUSIONS Our study suggests that nutritional knowledge of hemodialysis patients, although higher than the general population, is lower for phosphorus with respect to the other nutrients, such as protein, sodium, and potassium. This occurs even in patients with hyperphosphatemia or those taking phosphate binder medications. Nurses showed the best scores; however, improvement is necessary, especially with regard to knowledge of phosphorus. Training programs on nutrition for nurses and on information for patients should be implemented. They can contribute to achievement of a more effective control of phosphate balance, reduction of costs, and improvement of the quality of care for hemodialysis patients.