Assessment of the Knowledge of Phosphorus and Potassium in Hemodialysis Patients.

We aimed to determine the knowledge of potassium and phosphorus in patients undergoing hemodialysis (HD) and to associate it with serum levels and other clinical variables. This cross-sectional study included 73 patients of both sexes, who were over 18 years old and had undergone HD for at least 3 months at Hospital Geral de Caxias do Sul, Caxias do Sul, Brazil, between January and April 2019. Knowledge of phosphorus and potassium was measured by a questionnaire composed of 16 multiple choice questions (two general, seven about phosphorus, and seven about potassium) applied by the interviewer. For each mineral, a maximum of nine points could be scored. The mean ± standard deviation of correct answers was 9.78 ± 2.99 points for all questions, being higher for potassium (6.75 ± 1.65 points) than phosphorus (4.64 ± 2.10 points; P <0.001). A positive correlation was found between specific knowledge of phosphorus and its serum levels (r = 0.305; P = 0.009), but not for potassium (r = 0.101; P = 0.395). The number of correct answers positively correlated with the level of education (r = 0.390; P = 0.001) and negatively with age (r = -0.372; P = 0.001). The HD patients had intermediate levels of knowledge of phosphorus and potassium, with greater knowledge of potassium. Patients with higher serum phosphorus levels demonstrated greater knowledge about it, whereas this pattern was not observed for potassium levels. Knowledge of phosphorus and potassium was associated with younger patients and a higher level of education.