Cinacalcet Prescription Varies across US Hemodialysis Facilities

Since the implementation of the Medicare ESRD [end-stage renal disease] Prospective Payment System (PPS), i.e., bundle payments, dialysis facilities are reimbursed at a flat rate for a bundle of ESRD-related drugs, supplies, and services per dialysis treatment. Adjustment to the base rate is made to account for patient-level case-mix and facility-level factors that are associated with higher costs related to dialysis care delivery.

Of drugs used to manage persistently elevated serum levels of parathyroid hormone (PTH), hyperparathyroidism, as of 2018 only vitamin D analogs (administered orally and intravenously) have been incorporated into the bundle. By statutory provision, the addition of oral-only drugs (phosphate binders) has been delayed until 2025.

Beginning in January 2018 with the implementation of a Transitional Drug Add-on Payment Adjustment classification, calcimimetic treatments such as oral cinacalcet and intravenous etelcalcetide, are reimbursed separately under Medicare Part B. The adjustment is scheduled to remain in effect for a minimum of 2 years. During that time, the Centers for Medicare & Medicaid Services will collect and analyze data on utilization and cost; following the analyses, the agency will determine the appropriate revisions to the bundle payment system, including calcimimetics.

According to Douglas S. Fuller, MS, and colleagues, understanding patterns of calcimimetic utilization across dialysis facilities may help align financial incentives with clinical objectives. The researchers recently conducted an analysis of cross-sectional data from DOPPS (US Dialysis Outcomes and Practice Patterns Study) from 2014. Preliminary data from 2016 were used in a sensitivity analysis. Results of the analyses were reported online in the Clinical Journal of the American Society of Nephrology [doi:10.2215/CJN.09550818].

The monthly data were used to define the distribution of cinacalcet prescription across 203 hemodialysis facilities in the United States, representing 10,521 patients. Linear mixed-effects regressions on the basis of associations with PTH levels from patient-level analyses were used to estimate the associations between three facility-level exposures (black race; age <65 years; and dialysis vintage [≥3 years]), and the prevalence of cinacalcet prescriptions, adjusting for facility- and patient-level potential confounders.

There was a steady increase in the median percentage of patients in facilities with cinacalcet prescription during 2014; the percentage increased from 22% to 24%, a difference of only 2% to 3% (slope per 30 days, 0.09%; 95% confidence interval [CI], 0.02% to 0.2%; P for trend=.01). The researchers also observed wide variability in cinacalcet prescription across facilities within each month; absolute differences between the 25th and 75th percentiles varied from 16% to 20% across months in 2014. In the sensitivity analysis of preliminary 2016 data, the estimated monthly percentages were slightly higher, but there were no other notable differences compared with the main analysis of 2014 data.

As the percentage of black patients in each facility increased from the lowest to the highest quartile, the mean percentage of patients with a cinacalcet prescription increased monotonically from 18% to 31%. There were similar monotonic associations with cinacalcet prescription in a facility for the percentages of patients <65 years of age and with dialysis vintage ≥3 years.

The highest levels of PTH were in patients in the quartile of facilities having the highest percentage of black patients (396 pg/mL), relative to patients in the first two quartiles. Those facilities also had the largest percentages of patients with PTH ≥600 pg/mL (28%) and albumin-corrected serum calcium <84 mg/dL (31%), and a lower percentage of patients with phosphorus levels ≥5.5 mg/dL (34%).

The highest median PTH levels were seen in patients in the top two quartiles of facilities with the largest percentage of patients <65 years of age; patients at those facilities also had nearly twice the percentage of patients with PTH ≥600 pg/mL (24% and 21%) compared with patients at the lowest quartile. The two highest quartile facilities in this category also had the highest percentage of patients with calcium levels ≥9.5 mg/dl (12% and 15%). The lowest median PTH levels were seen in patients in the quartile of facilities with the smallest percentage of patients with dialysis vintage ≥3 years.

The adjusted difference in prevalence of cinacalcet prescription between facilities with the highest and lowest quartiles of black patients was 7.8% (95% CI, 0.8% to 14.8%; P for trend=.03); 7.3% for the percentage of patients <65 years of age (95% CI, –0.1% to 14.7%; P for trend=.06), and 11.9% for the percentage of patients with dialysis vintage ≥3 years (95% CI, 2.4% to 21.4%; P for trend=.02). However, following further adjustment for patient-level exposure variables, the associations changed substantially, becoming much weaker or even reversing.

The researchers said that the key limitation to the study was not including other possible variables such as private insurance or Medicare/Medicaid dual coverage that induce similar systematic differences across facilities or may explain the differences seen in the analyses.

“In summary, we found considerable variability in the percentage of patients prescribed cinacalcet across Unites States hemodialysis facilities. Facilities treating more patients who are black, under age 65 years, and having dialysis vintage ≥3 years have systematically higher levels of cinacalcet prescription. These differences were only slightly influenced by facility situational factors, but were strongly attenuated after accounting for the unbalanced distributions of these patient-level case-mix variables. Existing ESRD PPS adjustments may not fully account for these imbalances, and thus additional studies evaluating the clinical and financial effects on facilities of adding calcimimetics to the bundle with respect to these three factors are warranted,” the researchers said.

Takeaway Points

  1. The Centers for Medicare & Medicaid Services is considering including calcimimetic drugs used to treat secondary hyperparathyroidism in the ESRD Prospective Payment System bundle.
  2. Researchers conducted a study using cross-sectional data to examine the distribution of cinacalcet prescriptions across 203 hemodialysis facilities in the United States.
  3. Facilities with higher percentages of patients who were  black, <65 years of age, and with dialysis vintage ≥3 years had higher average levels of cinacalcet prescription; however, the differences were substantially attenuated following adjustment for patient-level exposure variables.