Utilization and costs of medications associated with CKD mineral and bone disorder in dialysis patients enrolled in Medicare Part D

Understudied Hyperphosphatemia (Chronic Kidney Disease) Treatment Targets and New Biological Approaches

Hyperphosphatemia is a secondary disorder of chronic kidney disease that causes vascular calcifications and bone-mineral disorders. As per the US Centers for Disease Control and Prevention, renal damage requires first-priority medical attention for patients with COVID-19; according to a Johns Hopkins Medicine report, SARS-CoV-2 can cause renal damage. Therefore, addressing the research inputs required to manage hyperphosphatemia is currently in great demand. This review highlights research inputs, such as defects in the diagnosis of hyperphosphatemia, flaws in understanding the mechanisms associated with understudied tertiary toxicities, less cited adverse effects of phosphate binders that question their use in the market, socioeconomic challenges of renal treatment and public awareness regarding the management of a phosphate-controlled diet, novel biological approaches (synbiotics) to prevent hyperphosphatemia as safer strategies with potential additional health benefits, and future functional food formulations to enhance the quality of life. We have not only introduced our contributions to emphasise the hidden aspects and research gaps in comprehending hyperphosphatemia but also suggested new research areas to strengthen approaches to prevent hyperphosphatemia in the near future.

Parathyroidectomy Versus Cinacalcet for the Treatment of Secondary Hyperparathyroidism in Hemodialysis Patients

Background

Secondary hyperparathyroidism in patients with end stage renal disease on dialysis is associated with bone pain and fractures in addition to cardiovascular morbidity. Cinacalcet is the most commonly used drug to treat such patients, but it has never been compared to surgery. The goal of this study is to compare the long-term outcomes and survival between cinacalcet and parathyroidectomy in the treatment of secondary hyperparathyroidism in hemodialysis patients.

Methods

Adult patients on hemodialysis who were treated with cinacalcet or parathyroidectomy in the United States Renal Data System were included. Patients treated with surgery (n = 2023) were compared using 1:1 propensity score matching ratio to a cohort of patients treated with cinacalcet. A Cox regression analysis was conducted to compare the overall mortality.

Results

The propensity score matching successfully created two groups with similar demographics. Patients in the surgery group had a higher mean peak PTH level prior to therapy (2066.8 vs 1425.4, P < 0.001). No difference was observed in the development of new-onset coronary artery disease (7.7% vs 7.9%, P = 0.8) or cerebrovascular disease (7% vs 6.7%, P = 0.8). Surgical patients had a higher rate of pathologic fractures (27.8% vs 24.9%, P = 0.04). Survival analysis showed that patients undergoing surgery had a better 5-year survival (65.6% vs 57.8%) and were less likely to die within the study period (HR 0.77, 95% CI 0.7–0.85, P < 0.0001).

Conclusions

Patients on dialysis undergoing parathyroidectomy for the treatment of secondary hyperparathyroidism have a better overall survival than those treated with cinacalcet.

Medication Burden and Prescribing Patterns in Patients on Hemodialysis in the USA, 2013-2017

INTRODUCTION

The medication burden of patients with end-stage renal disease (ESRD) on hemodialysis, a patient population with a high comorbidity burden and complex care requirements, is among the highest of any of the chronic diseases. The goal of this study was to describe the medication burden and prescribing patterns in a contemporary cohort of patients with ESRD on hemodialysis in the USA.

METHODS

We used the United States Renal Data System database from January 1, 2013, and December 31, 2017, to quantify the medication burden of patients with ESRD on hemodialysis aged ≥18 years. We calculated the average number of prescription medications per patient during each respective year (January-December), number of medications within classes, including potentially harmful medications, and trends in the number of medications and classes over the 5-year study period.

RESULTS

We included a total of 163,228 to 176,133 patients from 2013 to 2017. The overall medication burden decreased slightly, from a mean of 7.4 (SD 3.8) medications in 2013 to 6.8 (SD 3.6) medications in 2017. Prescribing of potentially harmful medications decreased over time (74.0% with at least one harmful medication class in 2013-68.5% in 2017). In particular, the prescribing of non-benzodiazepine hypnotics, benzodiazepines, and opioids decreased from 2013 to 2017 (12.2%-6.3%, 23.4%-19.3%, and 60.0%-53.4%, respectively). This trend was consistent across subgroups of age, sex, race, and low-income subsidy status.

CONCLUSIONS

Patients with ESRD on hemodialysis continued to have a high overall medication burden, with a slight reduction over time accompanied by a decrease in prescribing of several classes of harmful medications. Continued emphasis on assessment of appropriateness of high medication burden in patients with ESRD is needed to avoid exposure to potentially harmful or futile medications in this patient population.

Calcimimetic Use in Dialysis-Dependent Medicare Fee-for-Service Beneficiaries and Implications for Bundled Payment

BACKGROUND

Patients who are dialysis dependent and have secondary hyperparathyroidism (SHPT) may require calcimimetics to reduce parathyroid hormone levels to treatment goals. Medicare currently uses the Transitional Drug Add-on Payment Adjustment (TDAPA) designation under the ESKD Prospective Payment System ("bundled payment") to pay for calcimimetics (the first products eligible for the adjustment); this payment designation for calcimimetics is expected to conclude after 2020. This study explores variability in calcimimetic use across key patient characteristics and its potential effect on policy options for incorporating calcimimetics permanently into the bundle.

METHODS

This descriptive analysis used the 100% sample of Medicare FFS Part B (outpatient) 2018 claims to describe national-, regional-, and patient-level variation (including race, dual eligibility, and dialysis vintage) in calcimimetic use among beneficiaries who are dialysis dependent.

RESULTS

A total of 373,874 beneficiaries were analyzed, 28% had ≥90 days of calcimimetic use during 2018. At the national level, the proportion of patients on dialysis using calcimimetics was roughly 80% higher in Black versus non-Black patients on dialysis, 30% higher in patients on dialysis who were dual eligible versus non-dual eligible, and three times higher in patients with a dialysis vintage ≥3 years versus <3 years (all results unadjusted). Calcimimetic use was similar across census regions, however, substantial variation in calcimimetic use was observed at the facility level. Medicare spending for calcimimetic therapies as a proportion of total Medicare dialysis spending was >10% in approximately 20% of dialysis facilities.

CONCLUSIONS

Although less than a third of beneficiaries use calcimimetics, certain patient-level characteristics are associated with higher rates of maintenance calcimimetic use. Due to the financial pressure many dialysis facilities face, how calcimimetics are incorporated into the bundle may have a direct effect on facility reimbursement for, and patient access to, therapy. Careful consideration will be required to ensure patients who are vulnerable and require treatment for SHPT do not face barriers to appropriate care.

Muscle Relaxant Use Among Hemodialysis Patients: Prevalence, Clinical Indications, and Adverse Outcomes

RATIONALE & OBJECTIVE

Muscle relaxants are often used to treat musculoskeletal pain or cramping, which are commonly experienced by hemodialysis patients. However, the extent to which muscle relaxants are prescribed in this population and the risks associated with their use have not been characterized.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

140,899 Medicare-covered adults receiving hemodialysis in 2011, identified in the US Renal Data System.

EXPOSURE

Time-varying muscle relaxant exposure.

OUTCOMES

Primary outcomes were time to first emergency department visit or hospitalization for altered mental status, fall, or fracture. Secondary outcomes were death and composites of death with each of the primary outcomes.

ANALYTICAL APPROACH

Multivariable Cox regression analysis.

RESULTS

10% of patients received muscle relaxants in 2011. 11%, 6%, 3%, and 13% had an episode of altered mental status, fall, fracture, and death, respectively. Muscle relaxant use was associated with higher risk for altered mental status (HR, 1.39; 95% CI, 1.29-1.51) and fall (HR, 1.18; 95% CI, 1.05-1.33) compared to no use. Muscle relaxant use was not statistically significantly associated with higher risk for fracture (HR, 1.17; 95% CI, 0.98-1.39). Muscle relaxant use was associated with lower hazard of death (HR, 0.85; 95% CI, 0.76-0.94). However, hazards were higher for altered mental status or death (HR, 1.17; 95% CI, 1.10-1.25), fall or death (HR, 1.14; 95% CI, 1.06-1.22), and fracture or death (HR, 1.10; 95% CI, 1.01-1.20).

LIMITATIONS

A causal association between muscle relaxant use and outcomes cannot be inferred, and residual confounding cannot be excluded. Exposure and outcomes were ascertained using administrative claims.

CONCLUSIONS

Muscle relaxant use was common in hemodialysis patients and associated with altered mental status and falls. We could not rule out a clinically meaningful association between muscle relaxant use and fracture. The lower risk for death with muscle relaxants may have been the result of residual confounding. Future research to define the appropriate use of muscle relaxants in this population is warranted.

Psychoactive Medications and Adverse Outcomes among Older Adults Receiving Hemodialysis

BACKGROUND

Guidelines recommend avoidance of several psychoactive medications such as hypnotics in older adults due to their adverse effects. Older patients on hemodialysis may be particularly vulnerable to complications related to use of these agents, but only limited data are available about the risks in this population.

OBJECTIVES

To evaluate the association between the use of psychoactive medications and time to first emergency department visit or hospitalization for altered mental status, fall, and fracture among older patients receiving hemodialysis.

DESIGN

Observational cohort study.

SETTING

National registry of patients receiving hemodialysis (US Renal Data System).

PARTICIPANTS

A total of 60 007 adults 65 years or older receiving hemodialysis with Medicare Part D coverage in 2011.

MEASUREMENTS

The predictors were use of sedative-hypnotics and anticholinergic antidepressants (modeled as separate time-varying exposures). The outcomes were time to first emergency department visit or hospitalization for altered mental status, fall, and fracture (modeled separately).

RESULTS

Overall, 17% and 6% used sedative-hypnotics and anticholinergic antidepressants, respectively, in 2011. In multivariable-adjusted Cox regression, anticholinergic antidepressant use was associated with a 25%, 27%, and 39% higher hazard of altered mental status, fall, and fracture, respectively, compared with no use. Use of sedative-hypnotics was not associated with adverse outcomes.

CONCLUSION

Anticholinergic antidepressants were associated with adverse outcomes in older hemodialysis patients, and alternative treatments should be considered. Sedative-hypnotics were not associated with the risks evaluated in this study, but further investigation of the harms of this class of agents is warranted before their recommendation as a treatment option for insomnia in this population. J Am Geriatr Soc 67:449-454, 2019.

Leveraging pragmatic clinical trial design to advance phosphate management in end-stage renal disease

PURPOSE OF REVIEW

Phosphate lowering toward the normal range is advocated and widely practiced in patients with end-stage renal disease receiving dialysis. This approach is guided by basic science data and large observational studies that have demonstrated a consistent association between hyperphosphatemia and adverse events, including cardiovascular morbidity and all-cause mortality. There has never been a clinical trial to assess the efficacy of phosphate lowering in maintenance dialysis recipients.

RECENT FINDINGS

Despite several trials comparing the effect of different phosphate-binding agents on biochemical targets, no trial has evaluated whether targeting normophosphatemia using phosphate binders mediates better patient outcomes. Recent work has highlighted the feasibility of conducting a randomized trial comparing two strategies for phosphate control. We believe that this research question is optimally suited to a pragmatic trial design.

SUMMARY

There is a pressing need for a well-designed randomized controlled trial to evaluate whether intensive phosphate lowering confers improved cardiovascular outcomes in patients receiving maintenance dialysis. We propose a broad framework for such a trial using the principles of pragmatic trial design. The ultimate objective of such a trial will be to provide patients and clinicians with reliable and broadly applicable information on whether reducing serum phosphate toward the normal range improves patient-important outcomes.

Evidence basis for integrated management of mineral metabolism in patients with end-stage renal disease

PURPOSE OF REVIEW

Treatment of mineral metabolism is a mainstay of dialysis care including some of its most widely used and costly pharmaceuticals. Although many mineral metabolites are associated with increased risk of mortality, cardiovascular disease, and other morbidities, few clinical trials are available to guide therapy and most focus on single drug approaches. In practice, providers manage many aspects of mineral metabolism simultaneously in integrated treatment approaches that incorporate multiple agents and changes in the dialysis prescription. The present review discusses the rationale and existing evidence for evaluating integrated, as opposed to single drug, approaches in mineral metabolism.

RECENT FINDINGS

Drugs used to treat mineral metabolism have numerous, and sometimes, opposing effects on biochemical risk factors, such as fibroblast growth factor 23 (FGF23), calcium, and phosphorus. Although vitamin D sterols raise these risk markers when lowering parathyroid hormone (PTH), calcimimetics lower them. Trials demonstrate that combined approaches best 'normalize' the mineral metabolism axis in end-stage renal disease (ESRD). Observations embedded within major trials of calcimimetics reveal that adjustment of calcium-based binders and dialysate calcium is a common approach to adverse effects of these drugs with some initial, but inconclusive, evidence that these co-interventions may impact outcomes.

SUMMARY

The multiple, and often opposing, biochemical effects of many mineral metabolism drugs provides a strong rationale for studying integrated management strategies that consider combinations of drugs and co-interventions as a whole. This remains a current gap in the field with opportunities for clinical trials.

Association of Medicare's Bundled Payment Reform With Changes in Use of Vitamin D Among Patients Receiving Maintenance Hemodialysis: An Interrupted Time-Series Analysis

BACKGROUND & RATIONALE

Medicare's 2011 prospective payment system (PPS) was introduced to curb overuse of separately billable injectable drugs. After epoietin, intravenous (IV) vitamin D analogues are the biggest drug cost drivers in hemodialysis (HD) patients, but the association between PPS introduction and vitamin D therapy has been scarcely investigated.

STUDY DESIGN

Interrupted time-series analyses.

SETTING & PARTICIPANTS

Adult US HD patients represented in the US Renal Data System between 2008 and 2013.

EXPOSURES

PPS implementation.

OUTCOMES

The cumulative dose of IV vitamin D analogues (paricalcitol equivalents) per patient per calendar quarter in prevalent HD patients. The average starting dose of IV vitamin D analogues and quarterly rates of new vitamin D use (initiations/100 person-months) in incident HD patients within 90 days of beginning HD therapy.

ANALYTICAL APPROACH

Segmented linear regression models of the immediate change and slope change over time of vitamin D use after PPS implementation.

RESULTS

Among 359,600 prevalent HD patients, IV vitamin D analogues accounted for 99% of the total use, and this trend was unchanged over time. PPS resulted in an immediate 7% decline in the average dose of IV vitamin D analogues (average baseline dose = 186.5 μg per quarter; immediate change = -13.5 μg [P < 0.001]; slope change = 0.43 per quarter [P = 0.3]) and in the starting dose of IV vitamin D analogues in incident HD patients (average baseline starting dose = 5.22 μg; immediate change = -0.40 μg [P < 0.001]; slope change = -0.03 per quarter [P = 0.03]). The baseline rate of vitamin D therapy initiation among 99,970 incident HD patients was 44.9/100 person-months and decreased over time, even before PPS implementation (pre-PPS β = -0.46/100 person-months [P < 0.001]; slope change = -0.19/100 person-months [P = 0.2]). PPS implementation was associated with an immediate change in initiation levels (by -4.5/100 person-months; P < 0.001).

LIMITATIONS

Incident HD patients were restricted to those 65 years or older.

CONCLUSION

PPS implementation was associated with a 7% reduction in the average dose and starting dose of IV vitamin D analogues and a 10% reduction in the rate of vitamin D therapy initiation.

Gabapentin and Pregabalin Use and Association with Adverse Outcomes among Hemodialysis Patients

Background Gabapentin and pregabalin are used to manage neuropathic pain, pruritus, and restless legs syndrome in patients on hemodialysis. These patients may be especially predisposed to complications related to these agents, which are renally cleared, but data regarding the risk thereof are lacking.Methods From the US Renal Data System, we identified 140,899 Medicare-covered adults receiving hemodialysis with Part D coverage in 2011. Using Cox regression models in which we adjusted for demographics, comorbidities, duration of exposure, number of medications, and use of potentially confounding concomitant medications, we investigated the association between gabapentin and pregabalin, modeled as separate time-varying exposures, and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture. We evaluated risk according to daily dose categories: gabapentin (>0-100, >100-200, >200-300, and >300 mg) and pregabalin (>0-100 and >100 mg).Results In 2011, 19% and 4% of patients received gabapentin and pregabalin, respectively. Sixty-eight percent of gabapentin or pregabalin users had a diagnosis of neuropathic pain, pruritus, or restless legs syndrome. Gabapentin was associated with 50%, 55%, and 38% higher hazards of altered mental status, fall, and fracture, respectively, in the highest dose category, but even lower dosing was associated with a higher hazard of altered mental status (31%-41%) and fall (26%-30%). Pregabalin was associated with up to 51% and 68% higher hazards of altered mental status and fall, respectively.Conclusions Gabapentin and pregabalin should be used judiciously in patients on hemodialysis, and research to identify the most optimal dosing is warranted.

Opioid Analgesics and Adverse Outcomes among Hemodialysis Patients

BACKGROUND AND OBJECTIVES

Patients on hemodialysis frequently experience pain and may be particularly vulnerable to opioid-related complications. However, data evaluating the risks of opioid use in patients on hemodialysis are limited.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the US Renal Data System, we conducted a cohort study evaluating the association between opioid use (modeled as a time-varying exposure and expressed in standardized oral morphine equivalents) and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture among 140,899 Medicare-covered adults receiving hemodialysis in 2011. We evaluated risk according to average daily total opioid dose (>60 mg, ≤60 mg, and per 60-mg dose increment) and specific agents (per 60-mg dose increment).

RESULTS

The median age was 61 years old, 52% were men, and 50% were white. Sixty-four percent received opioids, and 17% had an episode of altered mental status (15,658 events), fall (7646 events), or fracture (4151 events) in 2011. Opioid use was associated with risk for all outcomes in a dose-dependent manner: altered mental status (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.23 to 1.34; higher dose: hazard ratio, 1.67; 95% confidence interval, 1.56 to 1.78; hazard ratio, 1.29 per 60 mg; 95% confidence interval, 1.26 to 1.33), fall (lower dose: hazard ratio, 1.28; 95% confidence interval, 1.21 to 1.36; higher dose: hazard ratio, 1.45; 95% confidence interval, 1.31 to 1.61; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.03 to 1.05), and fracture (lower dose: hazard ratio, 1.44; 95% confidence interval, 1.33 to 1.56; higher dose: hazard ratio, 1.65; 95% confidence interval, 1.44 to 1.89; hazard ratio, 1.04 per 60 mg; 95% confidence interval, 1.04 to 1.05). All agents were associated with a significantly higher hazard of altered mental status, and several agents were associated with a significantly higher hazard of fall and fracture.

CONCLUSIONS

Opioids were associated with adverse outcomes in patients on hemodialysis, and this risk was present even at lower dosing and for agents that guidelines have recommended for use.

Prevention and treatment of hyperphosphatemia in chronic kidney disease

Hyperphosphatemia has consistently been shown to be associated with dismal outcome in a wide variety of populations, particularly in chronic kidney disease (CKD). Compelling evidence from basic and animal studies elucidated a range of mechanisms by which phosphate may exert its pathological effects and motivated interventions to treat hyperphosphatemia. These interventions consisted of dietary modifications and phosphate binders. However, the beneficial effects of these treatment methods on hard clinical outcomes have not been convincingly demonstrated in prospective clinical trials. In addition, exposure to high amounts of dietary phosphate may exert untoward actions even in the absence of overt hyperphosphatemia. Based on this concept, it has been proposed that the same interventions used in CKD patients with normal phosphate concentrations be used in the presence of hyperphosphatemia to prevent rise of phosphate concentration and as an early intervention for cardiovascular risk. This review describes conceptual models of phosphate toxicity, summarizes the evidence base for treatment and prevention of hyperphosphatemia, and identifies important knowledge gaps in the field.

Chitosan-Fe (III) Complex as a Phosphate Chelator in Uraemic Rats: A Novel Treatment Option

Phosphate retention and hyperphosphataemia are associated with increased mortality in patients with chronic kidney disease (CKD). We tested the use of cross-linked iron chitosan III (CH-FeCl) as a potential phosphate chelator in rats with CKD. We evaluated 96 animals, divided equally into four groups (control, CKD, CH-FeCl and CKD/CH-FeCl), over 7 weeks. We induced CKD by feeding animals an adenine-enriched diet (0.75% in the first 4 weeks and 0.1% in the following 3 weeks). We administered 30 mg/kg daily of the test polymer, by gavage, from the third week until the end of the study. All animals received a diet supplemented with 1% phosphorus. Uraemia was confirmed by the increase in serum creatinine in week 4 (36.24 ± 18.56 versus 144.98 ± 22.1 μmol/L; p = 0.0001) and week 7 (41.55 ± 22.1 versus 83.98 ± 18.56 μmol/L; p = 0.001) in CKD animals. Rats from the CKD group treated with CH-FeCl had a 54.5% reduction in serum phosphate (6.10 ± 2.23 versus 2.78 ± 0.55 mmol/L) compared to a reduction of 25.6% in the untreated CKD group (4.75 ± 1.45 versus 3.52 ± 0.74 mmol/L, p = 0.021), between week 4 and week 7. At week 7, renal function in both CKD groups was similar (serum creatinine: 83.98 ± 18.56 versus 83.10 ± 23.87 μmol/L, p = 0.888); however, the CH-FeCl-treated rats had a reduction in phosphate overload measured by fractional phosphate excretion (FEPi) (0.71 ± 0.2 versus 0.4 ± 0.16, p = 0.006) compared to the untreated CKD group. Our study demonstrated that CH-FeCl had an efficient chelating action on phosphate.

Cardiovascular calcifications in chronic kidney disease: Potential therapeutic implications

Cardiovascular (CV) calcification is a highly prevalent condition at all stages of chronic kidney disease (CKD) and is directly associated with increased CV and global morbidity and mortality. In the first part of this review, we have shown that CV calcifications represent an important part of the CKD-MBD complex and are a superior predictor of clinical outcomes in our patients. However, it is also necessary to demonstrate that CV calcification is a modifiable risk factor including the possibility of decreasing (or at least not aggravating) its progression with iatrogenic manoeuvres. Although, strictly speaking, only circumstantial evidence is available, it is known that certain drugs may modify the progression of CV calcifications, even though a direct causal link with improved survival has not been demonstrated. For example, non-calcium-based phosphate binders demonstrated the ability to attenuate the progression of CV calcification compared with the liberal use of calcium-based phosphate binders in several randomised clinical trials. Moreover, although only in experimental conditions, selective activators of the vitamin D receptor seem to have a wider therapeutic margin against CV calcification. Finally, calcimimetics seem to attenuate the progression of CV calcification in dialysis patients. While new therapeutic strategies are being developed (i.e. vitamin K, SNF472, etc.), we suggest that the evaluation of CV calcifications could be a diagnostic tool used by nephrologists to personalise their therapeutic decisions.

Medicare Part D's Effects on Drug Utilization and Out-of-Pocket Costs: A Systematic Review

OBJECTIVE

To update a past systematic review on whether Medicare Part D changed drug utilization and out-of-pocket (OOP) costs overall and within subpopulations, and to identify evidence gaps.

DATA SOURCES/STUDY SETTING

Published and gray literature from 2010 to 2015 meeting prespecified screening criteria, including having a comparison group, and utilization or OOP cost outcomes.

STUDY DESIGN

We conducted a systematic literature review with a quality assessment.

DATA COLLECTION/EXTRACTION METHODS

For each study, we extracted information on study design, data sources, analytic methods, outcomes, and limitations. Because outcome measures vary across studies, we did a qualitative synthesis rather than meta-analysis.

PRINCIPAL FINDINGS

Sixty-five studies met screening criteria. Overall, Medicare Part D enrollees have increased drug utilization and decreased OOP costs, but coverage gaps limit the program's impact. Beneficiaries whose insurance becomes more generous after enrollment had disproportionately increased drug utilization and decreased OOP costs. Outcomes among dual-eligibles were mixed.

CONCLUSIONS

There is strong evidence on how Medicare Part D and the donut hole coverage gap affect utilization and OOP costs, but weak evidence on how effects vary among dual-eligibles or across diseases. Findings suggest that the Affordable Care Act's provisions to expand coverage and reduce the donut hole should improve patient outcomes.

Rates and Outcomes of Parathyroidectomy for Secondary Hyperparathyroidism in the United States

BACKGROUND AND OBJECTIVES

Secondary hyperparathyroidism is common among patients with ESRD. Although medical therapy for secondary hyperparathyroidism has changed dramatically over the last decade, rates of parathyroidectomy for secondary hyperparathyroidism across the United States population are unknown. We examined temporal trends in rates of parathyroidectomy, in-hospital mortality, length of hospital stay, and costs of hospitalization.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, a representative national database on hospital stay regardless of age and payer in the United States, we identified parathyroidectomies for secondary hyperparathyroidism from 2002 to 2011. Data from the US Renal Data System reports were used to calculate the rate of parathyroidectomy.

RESULTS

We identified 32,971 parathyroidectomies for secondary hyperparathyroidism between 2002 and 2011. The overall rate of parathyroidectomy was approximately 5.4/1000 patients (95% confidence interval [95% CI], 5.0/1000 to 6.0/1000). The rate decreased from 2003 (7.9/1000 patients; 95% CI, 6.2/1000 to 9.6/1000), reached a nadir in 2005 (3.3/1000 patients; 95% CI, 2.6/1000 to 4.0/1000), increased again through 2006 (5.4/1000 patients; 95% CI, 4.4/1000 to 6.4/1000), and remained stable since that time. Rates of in-hospital mortality decreased from 1.7% (95% CI, 0.8% to 2.6%) in 2002 to 0.8% (95% CI, 0.1% to 1.6%) in 2011 (P for trend <0.001). In-hospital mortality rates were significantly higher in patients with heart failure (odds ratio [OR], 4.23; 95% CI, 2.59 to 6.91) and peripheral vascular disease (OR, 4.59; 95% CI, 2.75 to 7.65) and lower among patients with prior kidney transplantation (OR, 0.20; 95% CI, 0.06 to 0.65).

CONCLUSIONS

Despite the use of multiple medical therapies, rates of parathyroidectomy of secondary hyperparathyroidism have not declined in recent years.

Iron-based phosphate binders--a new element in management of hyperphosphatemia

INTRODUCTION

Management of serum phosphorus in patients with chronic kidney disease remains a significant clinical challenge. A pivotal component of the clinical approach to maintaining serum phosphorus concentrations towards the normal range is the use of phosphate binding agents in addition to comprehensive dietary counseling. The available agents work similarly by capitalizing on a cation within the agent to bind negatively charged phosphorus, forming an insoluble complex and reducing ingested phosphorus absorption. Despite several effective options for phosphate binder therapies, patient adherence remains an issue, mainly due to adverse effect profiles and large daily pill burdens.

AREAS COVERED

Two new iron-based phosphate binder therapies have recently become available in the United States, sucroferric oxyhydroxide and ferric citrate. These agents have both been shown to effectively reduce serum phosphorus comparably to widely used calcium-based binders and sevelamer salts.

EXPERT OPINION

The two new iron-based binders differ substantially with regard to phosphate binding chemistry and iron absorption profiles. Their place in therapy is still evolving and the impact of pill burden, gastrointestinal adverse effect profiles, potential cost reduction of anemia therapies and physiologic effects of long-term iron exposure need to be further evaluated.