BACKGROUND AND AIMS
Hyperphosphatemia is common in end-stage renal disease and increases the risk of fractures, cardiovascular disease and all-cause mortality. Achieving normal phosphate levels is dependent on optimization of dialysis, diet and phosphate medication. Home haemodialysis (HHD) offers exciting opportunities for individualised approaches to management, allowing for a more liberal, lifestyle-centred patient experience.
Our aim was to determine, in line with the UK Renal Association 2015 standards for Chronic Kidney Disease—Mineral Bone Disease (CKD-MBD), the percentage of patients in the North West London HHD program with:
METHOD
We conducted a retrospective review of the six most recent monthly biochemistry results for serum phosphate, corrected calcium and PTH levels of all patients actively receiving HHD under the care of Hammersmith Hospital (n = 33) between January and September 2020. Subsequently, a monthly multidisciplinary review of blood tests (with nephrologists, specialist nurses and dieticians) focusing on CKD-MBD parameters was implemented to facilitate timely prescription changes. Additionally, two questionnaires were conducted: (1) an adapted Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS) questionnaire assessed adherence with phosphate binders and (2) a diet questionnaire assessed dietary phosphate knowledge. At the end of 12 months, a re-audit was conducted in the patients from the original cohort (n = 23; following 4 transplants, 3 in-centre transitions and 3 deaths).
RESULTS
The initial audit revealed that of the 33 included patients, 14 (42%) recorded all bone parameters within the target range. Examining CKD-MBD parameters individually, 27 (82%) had adjusted calcium within target range [4 (12%) < 2.2 mmol/L and 1 (3%) > 2.6 mmol/L], 22 (66%) had a serum PTH in target range [9 (27%) > 9× ULN and 2 (8%) < 2× ULN, excluding those with parathyroidectomies] and 17 (51%) recorded a median serum phosphate within target [11 (33%) > 1.7 mmol/L and 5 (15%) <1.1 mmol/L].
Table 1 summarizes baseline demographics of the final audit group (n = 23). Re-audit after 12 months revealed 10 (43%) recorded all bone parameters within the target range. Examining CKD-MBD parameters individually, PTH targets had improved (from 66% to 83%). This was associated with increased use of calcimimetics, with 3 (17%) recording PTH > 9× ULN [from 9 (27%) at baseline]. However, there was no significant change in phosphate [12 (54%) within the target range, 7 (29%) above the range] and calcium [18 (78%) within the target range].
Of the 23 patients included for final analysis, 15 (65%) were actively prescribed phosphate binders. The BAASIS questionnaire revealed notable non-adherence, with 8 (53%) admitting to having missed doses in the last month, 5 (33%) consistently missing >4 doses and 6 (40%) not consuming alongside meals. Additionally, the dietary questionnaire revealed a lack of knowledge of hidden sources of dietary phosphate in all surveyed patients (n = 11 responses).
CONCLUSION
Based on UK Renal Association 2015 standards for CKD-MBD, in patients undergoing HHD:
