Low adherence to phosphate binders is recognized as a key contributor to poor control of hyperphosphatemia in dialysis patients. Whilst various methods to improve adherence to phosphate binders have been studied, the impact on healthcare cost of poor binder adherence has only recently been analysed. Ramakrishnan et al created a model to assess the healthcare cost savings associated with improved phosphate binder adherence and increased percent time in range (PTR) for target phosphorus levels in patients receiving haemodialysis.
The investigators used phosphate binder adherence rate and PTR data from 4,296 haemodialysis patients combined with Medicare data to estimate the monthly and annual incremental healthcare costs associated with different rates of adherence and PTR. Adherence was defined as medication possession ratio ≥ 80% and PTR defined at ≤ 5.5.mg/dL (KDOQI range).
This model was then used to study the impact of improving adherence and PTR on cost outcomes. The baseline phosphate binder adherence and PTR for adherent patients were hypothetically and simultaneously increased by increments of 10% and 20% respectively, to a total improvement of 30% and 60% in Scenario 3.
The data suggests that increased adherence to phosphate binder therapy and improved time within the KDOQI serum phosphorus range leads to savings, mainly driven by a reduction in inpatient costs. This is consistent with previous studies that demonstrated an increased risk of hospitalization from complications due to hyperphosphatemia in dialysis patients.
Improving adherence to reduce costs
There are several factors affecting patient adherence to treatment, which have been summarised in a paper by Rakov et al, including:
- Patient age and socioeconomic status,
- Patient understanding of the potential severity of hyperphosphatemia,
- Treatment side effects, and
- High pill burden
The authors of this paper also reviewed data for sucroferric oxyhydroxide, an iron-based phosphate binder with a low pill burden. When compared to sevelamer carbonate, similar reductions in serum phosphorus levels were achieved with an average of 2.8 sucroferric oxyhydroxide tablets and 7.6 sevelamer carbonate tablets at 12 weeks. Over 52 weeks of daily treatment, the mean number of sucroferric oxyhydroxide tablets taken each day was 3.3, versus 8.7 for sevelamer. Adherence was also greater for sucroferric oxyhydroxide; 83% at week 24 vs 77% in the sevelamer carbonate group.
Rakov and colleagues conclude that a combination of nurse-led interactions and lower pill burden could result in improved control of serum phosphorus levels and patient clinical outcomes.
- Rakov V, Chong E, Parker J. Tackling non-adherence in dialysis patients with hyperphosphataemia. J Ren Nurs. 2014;6(6):273-279. doi:10.12968/jorn.2014.6.6.273.
- Ramakrishnan K, Braunhofer P, Newsome B, et al. The Economic Impact of Improving Phosphate Binder Therapy Adherence and Attainment of Guideline Phosphorus Goals in Hemodialysis Patients: a Medicare Cost-Offset Model. Adv Ther. 2014;31(12):1272-1286. doi:10.1007/s12325-014-0170-4.
- Floege J, Covic AC, Ketteler M, et al. Long-term effects of iron-based phosphate binder, sucroferric oxyhydroxide, in dialysis patients. Nephrol Dial Transplant. February 2015:gfv006. doi:10.1093/ndt/gfv006.