Factors influencing adherence in chronic dialysis patients with hyperphosphatemia

Increasing patient knowledge of hyperphosphatemia and its treatment may enhance adherence to dietary phosphorus restriction and phosphate binder medications.

Abstract

Objective: To determine if patients with moderate hyperphosphatemia are more knowledgeable about hyperphosphatemia and its treatment than patients with severe hyperphosphatemia. Design: Observational study. Setting: University-affiliated outpatient dialysis center. Patients: Twenty-one stable, chronic hemodialysis or continuous ambulatory peritoneal dialysis patients with serum phosphorus concentrations greater than 4.5 mg/dL were divided into two groups based on moderate and severe hyperphosphatemia. Intervention: Participants were evaluated by questionnaire on their knowledge of hyperphosphatermia and its treatment. Patients' self-reported adherence to prescribed phosphate binder medication regimens was determined. Main Outcome Measure: Knowledge test scores, self-reported adherence scores, and social and medical variables were compared between the two groups. Results: Knowledge test scores in the moderately hyperphosphatemic group were statistically higher than in the severely hyperphosphatemic group. The occupation of the patient correlated with knowledge test score. Multiple regression analysis showed that, except for age, no other social or medical variables, including serum phosphorus levels, had a significant effect on self-reported adherence. Self-reported adherence was found to be an increasing function of the age of the patient. Overall, patient knowledge of hyperphosphatemia and its treatment was poor. Conclusion: Increasing patient knowledge of hyperphosphatemia and its treatment may enhance adherence to dietary phosphorus restriction and phosphate binder medications.