Multidisciplinary Team Versus a 'Phosphate Counting' APP for Serum Phosphate Control: A Randomized Controlled Trial

Abstract

Background: Hyperphosphatemia is almost universal in well-nourished patients with end stage kidney disease treated with dialysis due to an imbalance between dietary intake and phosphate removal via residual kidney function and dialysis. Although food phosphate content can vary dramatically between meals, the current standard is to prescribe a fixed dose of phosphate binder that may not match meal phosphate intake. The primary objective of our study was to determine if the use of an APP that matches phosphate binder dose with food phosphate content would be associated with an improvement in serum phosphate and a reduction in calcium carbonate intake compared to the multidisciplinary renal team. Methods: Eighty patients with end stage renal disease treated with peritoneal dialysis at a tertiary care hospital in Canada were randomized to the standard of care for serum phosphate management (multidisciplinary renal team) versus the OkKidney APP. Serum phosphate was measured at baseline and then monthly for 3 months with adjustments to phosphate management as deemed necessary by the multidisciplinary team (control) or the phosphate binder multiplier in the OkKidney APP (intervention) based on the laboratory values. The primary analysis was an un-paired t-test of the serum phosphate at study completion. Results: The participants were 56 (±14) years old, 54% were male; the most common cause of ESRD was diabetes mellitus. The serum phosphate was 1.96 (0.41) mmol/L and 1.85 (0.44) mmol/L in the control and intervention groups at the end of 3 months (p=0.30). The median elemental daily dose of calcium carbonate did not differ between the groups at study completion [587mg (309-928) versus 799mg (567-1183), p=0.29]. Conclusion: The OkKidney APP was associated with similar but not superior serum phosphate control to the standard of care which included renal dietician support.