Geographic variation of parathyroidectomy in patients receiving hemodialysis: a retrospective cohort analysis

BMC Surgery, Nov 2016

Background Secondary hyperparathyroidism (SHPT) is associated with adverse outcomes in patients receiving maintenance dialysis. Parathyroidectomy is a treatment for SHPT; whether parathyroidectomy utilization varies geographically in the US is unknown. Methods A retrospective cohort analysis was undertaken to identify all patients aged 18 years or older who were receiving in-center hemodialysis between 2007 and 2009, were covered by Medicare Parts A and B, and had been receiving hemodialysis for at least 1 year. Parathyroidectomy was identified from inpatient claims using relevant International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Patient characteristics and End-Stage Renal Disease Network (a proxy for geography) were ascertained. Adjusted odds ratios for parathyroidectomy were estimated from a logistic model. Results A total of 286,569 patients satisfied inclusion criteria, of whom 4435 (1.5%) underwent PTX. After adjustment for a variety of patient characteristics, there was a 2-fold difference in adjusted odds of parathyroidectomy between the most- and least-frequently performing regions. Adjusted odds ratios were more than 20% higher than average in four networks, and more than 20% lower in four networks. Conclusions Parathyroidectomy use varies substantially by geography in the US; the factors responsible should be further investigated.

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Geographic variation of parathyroidectomy in patients receiving hemodialysis: a retrospective cohort analysis

Wetmore et al. BMC Surgery Geographic variation of parathyroidectomy in patients receiving hemodialysis: a retrospective cohort analysis James B. Wetmore 0 1 2 Jiannong Liu 1 Paul J. Dluzniewski 5 Areef Ishani 1 2 4 Geoffrey A. Block 3 Allan J. Collins 1 2 0 Division of Nephrology, Hennepin County Medical Center , Minneapolis, MN , USA 1 Chronic Disease Research Group, Minneapolis Medical Research Foundation , 914 South 8th Street, Suite S4.100, Minneapolis, MN 55404 , USA 2 Department of Medicine, University of Minnesota , Minneapolis, MN , USA 3 Denver Nephrology Clinical Research Division , Denver, CO , USA 4 Section of Renal Diseases and Hypertension, Minneapolis Veterans Administration Health Care System , Minneapolis, MN , USA 5 Center for Observational Research, Amgen Inc , Thousand Oaks, CA , USA Background: Secondary hyperparathyroidism (SHPT) is associated with adverse outcomes in patients receiving maintenance dialysis. Parathyroidectomy is a treatment for SHPT; whether parathyroidectomy utilization varies geographically in the US is unknown. Methods: A retrospective cohort analysis was undertaken to identify all patients aged 18 years or older who were receiving in-center hemodialysis between 2007 and 2009, were covered by Medicare Parts A and B, and had been receiving hemodialysis for at least 1 year. Parathyroidectomy was identified from inpatient claims using relevant International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Patient characteristics and End-Stage Renal Disease Network (a proxy for geography) were ascertained. Adjusted odds ratios for parathyroidectomy were estimated from a logistic model. Results: A total of 286,569 patients satisfied inclusion criteria, of whom 4435 (1.5%) underwent PTX. After adjustment for a variety of patient characteristics, there was a 2-fold difference in adjusted odds of parathyroidectomy between the most- and least-frequently performing regions. Adjusted odds ratios were more than 20% higher than average in four networks, and more than 20% lower in four networks. Conclusions: Parathyroidectomy use varies substantially by geography in the US; the factors responsible should be further investigated. End-stage renal disease; Dialysis; Mineral metabolism; Parathyroidectomy; Secondary hyperparathyroidism - Background Secondary hyperparathyroidism (SHPT) is associated with adverse outcomes in patients receiving maintenance dialysis [1, 2]. Anecdotally, physicians appear to have widely variable criteria regarding which patients they choose to refer for parathyroidectomy, at least in the US. Perhaps reflecting uncertainty over its role, rates of parathyroidectomy have changed substantially over time in recent decades [3]. While guidelines recommend parathyroidectomy in patients with severe SHPT [4], how it might be used most optimally is uncertain. Parathyroidectomy has been shown to be associated with improved outcomes in some studies [5, 6]; however, it has also been shown to be associated with mortality, protracted hypocalcemia, and over-suppression of parathyroid hormone (PTH) [7], and its results with regard to mineral metabolic control are often suboptimal [8]. Thus, understanding the differences between hemodialysis patients who do and do not undergo parathyroidectomy may be important. However, the effect of geographic variation, which is associated with a variety of outcomes and care differences in the dialysis population [9, 10] has not been examined in the context of parathyroidectomy. We therefore conducted a retrospective cohort study to examine whether parathyroidectomy use varies geographically in the United States. Methods Using the United States Renal Data System end-stage renal disease database, we identified patients aged 18 years or older who were receiving in-center hemodialysis between 2007 and 2009, were covered by Medicare Part A (inpatient, outpatient, skilled nursing facility, hospice, or home health agency) and Part B (physician/supplier) as primary payer, and had been receiving hemodialysis for at least 1 year. Parathyroidectomy was identified from inpatient claims using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes 06.81 (complete parathyroidectomy), 06.89 (partial parathyroidectomy and parathyroidectomy not otherwise specified), and 06.95 (parathyroid tissue reimplantation). Patient characteristics, derived from the end-stage renal disease database Medical Evidence Report and Medicare claims, were assessed on the parathyroidectomy date and on January 1 for non-parathyroidectomy patients. Characteristics included age, sex, race, body mass index, cause of renal disease, dialysis duration, and common comorbid conditions, as have been used previously [11]. Our proxy for geography was US End-Stage Renal Disease Network (n = 18, Table 1), geographically based regions designed to facilitate care and monitor Table 1 End-stage renal disease netwo (...truncated)


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James Wetmore, Jiannong Liu, Paul Dluzniewski, Areef Ishani, Geoffrey Block, Allan Collins. Geographic variation of parathyroidectomy in patients receiving hemodialysis: a retrospective cohort analysis, BMC Surgery, 2016, pp. 77, 16, DOI: 10.1186/s12893-016-0193-7