Increasing rates of parathyroidectomy to treat secondary hyperparathyroidism in dialysis patients with Medicare coverage

Background: Secondary hyperparathyroidism affects nearly all patients with renal failure on dialysis. Medical treatment of secondary hyperparathyroidism has considerably evolved over the past 2 decades, with parathyroidectomy reserved for severe cases. The primary objective of our study was to understand how trends in medical treatments affected parathyroidectomy rates in patients with secondary hyperparathyroidism on dialysis. Methods: We used the United States Renal Data System to identify 379,835 adult patients (age ≥18) who were on maintenance dialysis in the United States between 2006 and 2016 with Medicare as the primary payor and ascertained treatment for secondary hyperparathyroidism. Adjusted rate ratios for rates of parathyroidectomy were calculated using multivariable-adjusted Poisson regression. Results: Of 379,835 secondary hyperparathyroidism patients, 4,118 (1.1%) underwent parathyroidectomy, 39,835 (10.5%) received cinacalcet, 243,522 (64.1%) received phosphate binders, 17,571 (4.6%) received vitamin D analogs, and 86,899 (22.9%) received no treatment during the 10 years of follow-up. Over the entire study period, there was a 3.5-fold increase in the use of calcimimetics and a 3.4-fold increase in rates of parathyroidectomy. Compared to 2006 through 2009, utilization of parathyroidectomy increased 52% (adjusted rate ratio = 1.52, 95% confidence interval: 1.39–1.65) between 2010 and 2013 and by 106% (adjusted rate ratio = 2.06, 95% confidence interval: 1.90–2.24) between 2014 and 2016. The greatest increase in parathyroidectomy utilization occurred in younger patients (age 18–64 years), Black patients, female patients, those living in higher poverty neighborhoods, those listed for kidney transplant, and those who live in the Southern region of the United States. Conclusion: Despite the evolution of medical treatments and an increase in the use of calcimimetics to treat secondary hyperparathyroidism, parathyroidectomy rates have been steadily increasing among dialysis patients with Medicare coverage.