Pill Burden, Adherence, Hyperphosphatemia, and Quality of Life in Maintenance Dialysis Patients

Background and objectives: Dialysis patients have a high burden of co-existing diseases, poor health-related quality of life (HR-QOL), and are prescribed many medications. There are no data on daily pill burden and its relationship to HR-QOL and adherence to therapy. Design, setting, participants, & measurements: Two hundred and thirty-three prevalent, chronic dialysis patients from three units in different geographic areas in the United States underwent a single, cross-sectional assessment of total daily pill burden and that from phosphate binders. HR-QOL, adherence to phosphate binders, and serum phosphorus levels were the three main outcome measures studied. Results: The median daily pill burden was 19; in one-quarter of subjects, it exceeded 25 pills/d. Higher pill burden was independently associated with lower physical component summary scale scores on HR-QOL on both univariate and multivariate analyses. Phosphate binders accounted for about one-half of the daily pill burden; 62% of the participants were nonadherent. There was a modest relationship between pill burden from phosphate binders and adherence and serum phosphorus levels; these associations persisted on multivariate analyses. There was no relationship between adherence and serum phosphorus levels. Conclusions: The daily pill burden in dialysis patients is one of the highest reported to date in any chronic disease state. Higher pill burden is associated with lower HR-QOL. There are many reasons for uncontrolled serum phosphorus levels; increasing the number of prescribed pills does not seem to improve control and may come at the cost of poorer HR-QOL. Clin J Am Soc Nephrol 4: 1089-1096, 2009. doi: 10.2215/CJN.00290109