Phosphate Binder Adherence and Perceived Cardiovascular Risk Among Young Adult Patients Receiving Maintenance Hemodialysis

Abstract

Background: Cardiovascular disease is the leading cause of death and disability among patients with End-Stage Renal Disease (ESRD). Hyperphosphatemia is an independent cardiovascular risk factor in patients undergoing maintenance hemodialysis. Most patients are on a class of medication called Phosphorus Binders, which they take with meals and snacks to absorb the phosphorus naturally present in their food. Unfortunately, not all patients who are prescribed binders will take them. This study is designed to explore the barriers to phosphate binder adherence in young adult patients on hemodialysis. We hypothesized that, among patients aged 18-44, this may be due to an inaccurate or incomplete understanding of their susceptibility to an adverse cardiovascular event, such as stroke or heart attack. Methods: Participants were recruited from hemodialysis clinics operated by a large, for-profit dialysis provider in Western Washington. Eligible patients who consented to participate in the study were interviewed 1:1 by the researcher. Selection criteria for eligible participants were as follows: 1) the participant had been on maintenance hemodialysis at least 90 days prior to the start of the study, 2) the participant was between the age of 18-44 years old at the time of interview, 3) the patient was oriented to person, place, and time, 4) the patient spoke fluent English, and 5) the patient was prescribed a phosphorus binder to take with meals. Results: Seven women and ten men completed the interview. Participants ranged in age from 20-41 years old. Approximately one-third of the participants identified increased risk of heart attack or stroke as a result of hyperphosphatemia. However, three-quarters of the participants were able to identify at least one negative health consequence, most often calciphylaxis and bone disease. The remaining patients verbalized understanding that high phosphorus was bad for their health, even if they could not identify a specific health outcome. Roughly half of the patients made statements that demonstrated high perceived risk to hyperphosphatemia-related disease outcomes and the other half made statements to suggest low perceived risk or no perceived risk. Physical, psychosocial, financial, and other barriers to optimal adherence were explored to create an informed picture of adherence variables. Conclusions: The results of this study support that most young adult patients on dialysis are aware that hyperphosphatemia has serious negative health consequences for renal patients. This study suggests that knowledge of deleterious outcomes related to hyperphosphatemia does not readily translate to optimal phosphorus management in young adults on dialysis and that psychosocial, clinical, and healthcare delivery variables all play a role in hindering optimal adherence.