Economic Evaluation in Kidney Transplantation: A Scoping Review and Novel PESTLE Stakeholder Gaps Analysis.

AIM: The objective of this study was to systematically review the literature related to the economic evaluation of kidney transplantation to determine the extent of current research and identify gaps for future research. SUBJECT AND METHODS: We searched 4 medical and 2 economic electronic databases as well as hand-searching reference lists of review articles and other pertinent articles. Exclusion criteria included articles that did not include original work (ie, reviews), were not in English, and were not journal articles or economic working papers (eg, commentaries, theses, abstracts). Full-text data abstraction included qualitative and quantitative parameters with the intent to perform a gap analysis for future research. RESULTS: A total of 299 articles were included and spanned a 48-year period from 1968 to 2016, with >73% published in 2000 or after. The most common topics included immunosuppression drugs, dialysis vs kidney transplantation, organ allocation, and the potential market for donor organs. Most articles were from the United States and originated from 73 medical journals and 34 economic journals or working paper centers. There were 58 articles dealing with costing, 153 using cost-effectiveness, 69 using economic modeling, 6 performing systematic reviews with meta-analyses, and 13 exploring the qualitative financial environment of individuals and the economy. CONCLUSIONS: Research gaps were identified in every parameter used to evaluate the studies, and a new system of gap analysis for scoping reviews was also proposed.

Evaluating Cost-Effectiveness in Using High-Kidney Donor Profile Index Organs.

A more granular donor kidney grading scale, the kidney donor profile index (KDPI), has recently emerged in contradistinction to the standard criteria donor/expanded criteria donor framework. In this paper, we built a Markov decision process model to evaluate the survival, quality-adjusted life years (QALY), and cost advantages of using high-KDPI kidneys based on multiple KDPI strata over a 60-month time horizon as opposed to remaining on the waiting list waiting for a lower-KDPI kidney. Data for the model were gathered from the Scientific Registry of Transplant Recipients and the United States Renal Data System Medicare parts A, B, and D databases. Of the 129,024 phenotypes delineated in this model, 65% of them would experience a survival benefit, 81% would experience an increase in QALYs, 87% would see cost-savings, and 76% would experience cost-savings per QALY from accepting a high-KDPI kidney rather than remaining on the waiting list waiting for a kidney of lower-KDPI. Classification and regression tree analysis (CART) revealed the main drivers of increased survival in accepting high-KDPI kidneys were wait time ≥30 months, panel reactive antibody (PRA) <90, age ≥45 to 65, diagnosis leading to renal failure, and prior transplantation. The CART analysis showed the main drivers of increased QALYs in accepting high-kidneys were wait time ≥30 months, PRA <90, and age ≥55 to 65.

Potential Unintended Consequences of National Infectious Disease Screening Strategies in Deceased Donor Kidney Transplantation: A Cost-Effectiveness Analysis.

BACKGROUND: In order to counter the lack of sufficient kidney donors, there has been interest in expanding the utilization of organs from increased infectious-risk donors. Negative nucleic acid testing of increased infectious-risk organs has been shown to increase their use as compared to only enzyme-linked immunosorbent assay negativity. However, it is not known how the expanded use of nucleic acid testing on a national scale might affect total donor utilization. OBJECTIVE: The objective of this paper was to determine if a national screening policy requiring the use of nucleic acid testing in both increased infectious-risk and non-increased infectious-risk renal transplant donors would increase the donor organ pool. METHODS: This study used decision-tree analysis to determine the cost-effectiveness of four US national screening policies based on an increasingly expansive use of nucleic acid testing for increased infectious-risk and non-increased infectious-risk kidneys. Parameters were taken from the literature. All costs were reported in 2020 US dollars using a Medicare payer perspective and a life-time horizon. RESULTS: The use of nucleic acid screening solely for increased infectious-risk organs was the dominant strategy. Our results were robust to deterministic and probabilistic sensitivity analyses. One of the main driving factors of cost-effectiveness was the false-positive rate of nucleic acid testing. CONCLUSION: Before implementing nucleic acid screening outside of increased infectious-risk organs, its false-positivity rate should be directly studied to ensure that its use does not detrimentally affect transplantation numbers, quality-adjusted life-years, and costs.

Staphylococcus Aureus Prevention Strategies in Cardiac Surgery: A Cost-Effectiveness Analysis.

BACKGROUND: Cardiac surgery patients colonized with Staphylococcus aureus have a greater risk of surgical site infection (SSI). The purpose of this study was to evaluate the cost-effectiveness of decolonization strategies to prevent SSIs. METHODS: We compared three decolonization strategies: universal decolonization (UD), all subjects treated; targeted decolonization (TD), only S aureus carriers treated; and no decolonization (ND). Decolonization included mupirocin, chlorhexidine, and vancomycin. We implemented a decision tree comparing the costs and quality-adjusted life-years (QALYs) of these strategies on SSI over a 1-year period for subjects undergoing coronary artery bypass graft surgery from a US health sector perspective. Deterministic and probabilistic sensitivity analyses were conducted to address the uncertainty in the variables. RESULTS: Universal decolonization was the dominant strategy because it resulted in reduced costs at near-equal QALYs compared with TD and ND. Compared with ND, UD decreased costs by $462 and increased QALYs by 0.002 per subject, whereas TD decreased costs by $205 and increased QALYs by 0.001 per subject. For 1,000 subjects, UD prevented 19 SSI and TD prevented 10 SSI compared with ND. Sensitivity analysis showed UD to be the most cost-effective strategy in more than 91% of simulations. For the 220,000 coronary artery bypass graft procedures performed yearly in the United States, UD would save $102 million whereas TD would save $45 million compared with ND. CONCLUSIONS: Universal decolonization outperforms other strategies. However, the potential costs savings of $57 million per 220,000 coronary artery bypass graft procedures comparing UD versus TD must be weighed against the potential risk of developing resistance associated with universal decolonization.

Individualized Performance Feedback to Surgical Residents Improves Appropriate Venous Thromboembolism Prophylaxis Prescription and Reduces Potentially Preventable VTE: A Prospective Cohort Study.

OBJECTIVE: To investigate the effect of providing personal clinical effectiveness performance feedback to general surgery residents regarding prescription of appropriate venous thromboembolism (VTE) prophylaxis. BACKGROUND: Residents are frequently charged with prescribing medications for patients, including VTE prophylaxis, but rarely receive individual performance feedback regarding these practice habits. METHODS: This prospective cohort study at the Johns Hopkins Hospital compared outcomes across 3 study periods: (1) baseline, (2) scorecard alone, and (3) scorecard plus coaching. All general surgery residents (n = 49) and surgical patients (n = 2420) for whom residents wrote admission orders during the first 9 months of the 2013-2014 academic year were included. Outcomes included the proportions of patients prescribed appropriate VTE prophylaxis, patients with preventable VTE, and residents prescribing appropriate VTE prophylaxis for every patient, and results from the Accreditation Council for Graduate Medical Education resident survey. RESULTS: At baseline, 89.4% of patients were prescribed appropriate VTE prophylaxis and only 45% of residents prescribed appropriate prophylaxis for every patient. During the scorecard period, appropriate VTE prophylaxis prescription significantly increased to 95.4% (P < 0.001). For the scorecard plus coaching period, significantly more residents prescribed appropriate prophylaxis for every patient (78% vs 45%, P = 0.0017). Preventable VTE was eliminated in both intervention periods (0% vs 0.35%, P = 0.046). After providing feedback, significantly more residents reported receiving data about practice habits on the Accreditation Council for Graduate Medical Education resident survey (87% vs 38%, P < 0.001). CONCLUSIONS: Providing personal clinical effectiveness feedback including data and peer-to-peer coaching improves resident performance, and results in a significant reduction in harm for patients.

Choosing the order of deceased donor and living donor kidney transplantation in pediatric recipients: a Markov decision process model.

BACKGROUND: Most pediatric kidney transplant recipients eventually require retransplantation, and the most advantageous timing strategy regarding deceased and living donor transplantation in candidates with only 1 living donor remains unclear. METHODS: A patient-oriented Markov decision process model was designed to compare, for a given patient with 1 living donor, living-donor-first followed if necessary by deceased donor retransplantation versus deceased-donor-first followed if necessary by living donor (if still able to donate) or deceased donor (if not) retransplantation. Based on Scientific Registry of Transplant Recipients data, the model was designed to account for waitlist, graft, and patient survival, sensitization, increased risk of graft failure seen during late adolescence, and differential deceased donor waiting times based on pediatric priority allocation policies. Based on national cohort data, the model was also designed to account for aging or disease development, leading to ineligibility of the living donor over time. RESULTS: Given a set of candidate and living donor characteristics, the Markov model provides the expected patient survival over a time horizon of 20 years. For the most highly sensitized patients (panel reactive antibody > 80%), a deceased-donor-first strategy was advantageous, but for all other patients (panel reactive antibody < 80%), a living-donor-first strategy was recommended. CONCLUSIONS: This Markov model illustrates how patients, families, and providers can be provided information and predictions regarding the most advantageous use of deceased donor versus living donor transplantation for pediatric recipients.

A single institution's 26-year experience with nonfunctional pancreatic neuroendocrine tumors: a validation of current staging systems and a new prognostic nomogram.

OBJECTIVE: To validate the 2010 American Joint Committee on Cancer (AJCC) and 2006 European Neuroendocrine Tumor Society (ENETS) tumor staging systems for pancreatic neuroendocrine tumors (PanNETs) using the largest, single-institution series of surgically resected patients in the literature. BACKGROUND: The natural history and prognosis of PanNETs have been poorly defined because of the rarity and heterogeneity of these neoplasms. Currently, there are 2 main staging systems for PanNETs, which can complicate comparisons of reports in the literature and thereby hinder progress against this disease. METHODS: Univariate and multivariate analyses were conducted on the prognostic factors of survival using 326 sporadic, nonfunctional, surgically resected PanNET patients who were cared for at our institution between 1984 and 2011. Current and proposed models were tested for survival prognostication validity as measured by discrimination (Harrel's c-index, HCI) and calibration. RESULTS: Five-year overall-survival rates for AJCC stages I, II, and IV are 93% (88%-99%), 74% (65%-83%), and 56% (42%-73%), respectively, whereas ENETS stages I, II, III, and IV are 97% (92%-100%), 87% (80%-95%), 73% (63%-84%), and 56% (42%-73%), respectively. Each model has an HCI of 0.68, and they are no different in their ability to predict survival. We developed a simple prognostic tool just using grade, as measured by continuous Ki-67 labeling, sex, and binary age that has an HCI of 0.74. CONCLUSIONS: Both the AJCC and ENETS staging systems are valid and indistinguishable in their survival prognostication. A new, simpler prognostic tool can be used to predict survival and decrease interinstitutional mistakes and uncertainties regarding these neoplasms.

Grading of well-differentiated pancreatic neuroendocrine tumors is improved by the inclusion of both Ki67 proliferative index and mitotic rate.

The grading system for pancreatic neuroendocrine tumors (PanNETs) adopted in 2010 by the World Health Organization (WHO) mandates the use of both mitotic rate and Ki67/MIB-1 index in defining the proliferative rate and assigning the grade. In cases when these measures are not concordant for grade, it is recommended to assign the higher grade, but specific data justifying this approach do not exist. Thus, we counted mitotic figures and immunolabeled, using the Ki67 antibody, 297 WHO mitotic grade 1 and 2 PanNETs surgically resected at a single institution. We quantified the Ki67 proliferative index by marking at least 500 cells in "hot spots" and by using digital image analysis software to count each marked positive/negative cell and then compared the results with histologic features and overall survival. Of 264 WHO mitotic grade 1 PanNETs, 33% were WHO grade 2 by Ki67 proliferative index. Compared with concordant grade 1 tumors, grade-discordant tumors were more likely to have metastases to lymph node (56% vs. 34%) (P<0.01) and to distant sites (46% vs. 12%) (P<0.01). Discordant mitotic grade 1 PanNETs also showed statistically significantly more infiltrative growth patterns, perineural invasion, and small vessel invasion. Overall survival was significantly different (P<0.01), with discordant mitotic grade 1 tumors showing a median survival of 12 years compared with 16.7 years for concordant grade 1 tumors. Conversely, mitotic grade 1/Ki67 grade 2 PanNETs showed few significant differences from tumors that were mitotic grade 2 and either Ki67 grade 1 or 2. Our data demonstrate that mitotic rate and Ki67-based grades of PanNETs are often discordant, and when the Ki67 grade is greater than the mitotic grade, clinical outcomes and histopathologic features are significantly worse than concordant grade 1 tumors. Patients with discordant mitotic grade 1/Ki67 grade 2 tumors have shorter overall survival and larger tumors with more metastases and more aggressive histologic features. These data strongly suggest that Ki67 labeling be performed on all PanNETs in addition to mitotic rate determination to define more accurately tumor grade and prognosis.

Cystic pancreatic neuroendocrine tumors: a clinicopathologic study.

Pancreatic neuroendocrine tumors (PanNETs) are typically solid neoplasms but in rare instances may present as cystic lesions. This unusual presentation can make clinical diagnosis challenging. In addition, the clinical and histopathologic characteristics of cystic PanNETs are poorly defined. We identified 53 cystic PanNETs in our single-institution experience of 491 surgically resected PanNETs. Similar to solid PanNETs, cystic PanNETs developed with an equal sex distribution and over a wide age range (23 to 91 y; mean, 52 y). The unusual cystic appearance made radiologic differentiation from other cystic pancreatic neoplasms difficult with a misdiagnosis in 23 of 53 (43%) cases. An association between cystic PanNETs and multiple endocrine neoplasia type 1 or multifocal disease [5 of 53 (9%) and 7 of 53 (13%), respectively] was not observed as compared with solid PanNETs (P=0.34 and P=0.31, respectively). Grossly, cystic PanNETs were predominantly located in the tail of the pancreas (n=28, 53%) and were similar in size (mean, 3.3 cm) to solid PanNETs (mean, 4.1 cm; P=0.12). All cysts were unilocular (n=53, 100%) and filled with clear to straw-colored fluid. Larger cysts were sometimes noted to be hemorrhagic. Histologically, the cysts were lined by a thin fibrous band that separated the cyst from the neoplastic cells. In comparison with their solid counterparts, cystic PanNETs were less likely to demonstrate tumor necrosis (6%; P=0.04), perineural invasion (8%; P<0.001), vascular invasion (4%; P<0.001), regional lymph node metastasis (13%; P<0.001), and synchronous distant metastasis (4%; P=0.015). The neoplastic cells of the cystic PanNETs were well differentiated (n=53, 100%) with a low mitotic rate and low Ki-67 proliferation index (range, 0.2% to 11%; mean, 1.8%). On the basis of both the American Joint Cancer Committee and European Neuroendocrine Tumor Society staging systems, the majority of cystic PanNETs presented at a lower pathologic stage as compared with solid PanNETs. In summary, cystic PanNETs are a distinctive subgroup of PanNETs with unique clinical, radiographic, and pathologic features.

The current management of pancreatic neuroendocrine tumors.

PanNETs constitute a rare and heterogeneous group of pancreatic neoplasms whose overall prognosis is better than the more common pancreatic adenocarcinoma. Although surgery is the only treatment that provides a cure, many adjuvant therapies have been explored with some new, exciting, targeted therapies just approved for PanNETs. With growing interest in this type of neoplasm, an increasing number of clinical trials and natural history studies should shed light on the best management for these patients.

Loss of ATRX or DAXX expression and concomitant acquisition of the alternative lengthening of telomeres phenotype are late events in a small subset of MEN-1 syndrome pancreatic neuroendocrine tumors.

Approximately 45% of sporadic well-differentiated pancreatic neuroendocrine tumors harbor mutations in either ATRX (alpha thalassemia/mental retardation X-linked) or DAXX (death domain-associated protein). These novel tumor suppressor genes encode nuclear proteins that interact with one another and function in chromatin remodeling at telomeric and peri-centromeric regions. Mutations in these genes are associated with loss of their protein expression and correlate with the alternative lengthening of telomeres phenotype. Patients with multiple endocrine neoplasia-1 (MEN-1) syndrome, genetically defined by a germ line mutation in the MEN1 gene, are predisposed to developing pancreatic neuroendocrine tumors and thus represent a unique model for studying the timing of ATRX and DAXX inactivation in pancreatic neuroendocrine tumor development. We characterized ATRX and DAXX protein expression by immunohistochemistry and telomere status by telomere-specific fluorescence in situ hybridization in 109 well-differentiated pancreatic neuroendocrine lesions from 28 MEN-1 syndrome patients. The study consisted of 47 neuroendocrine microadenomas (<0.5 cm), 50 pancreatic neuroendocrine tumors (≥0.5 cm), and 12 pancreatic neuroendocrine tumor lymph node metastases. Expression of ATRX and DAXX was intact in all 47 microadenomas, and none showed the alternative lengthening of telomeres phenotype. ATRX and/or DAXX expression was lost in 3 of 50 (6%) pancreatic neuroendocrine tumors. In all three of these, tumor size was ≥3 cm, and loss of ATRX and/or DAXX expression correlated with the alternative lengthening of telomeres phenotype. Concurrent lymph node metastases were present for two of the three tumors, and each metastasis displayed the same changes as the primary tumor. These findings establish the existence of ATRX and DAXX defects and the alternative lengthening of telomeres phenotype in pancreatic neuroendocrine tumors in the context of MEN-1 syndrome. The observation that ATRX and DAXX defects and the alternative lengthening of telomeres phenotype occurred only in pancreatic neuroendocrine tumors measuring ≥3 cm and their lymph node metastases suggests that these changes are late events in pancreatic neuroendocrine tumor development.

Serotonin expression in pancreatic neuroendocrine tumors correlates with a trabecular histologic pattern and large duct involvement.

Pancreatic neuroendocrine tumors with prominent stromal fibrosis are often clinically, radiographically, and grossly indistinguishable from ductal adenocarcinoma. We recently described a small series of fibrotic pancreatic neuroendocrine tumors that express serotonin. To understand better the relationship between histopathologic patterns and serotonin expression, we reviewed 361 pancreatic neuroendocrine tumors to identify those with prominent stromal fibrosis exceeding 30% of total tumor area. We identified 52 cases and immunolabeled these neoplasms with antibodies to serotonin and Ki-67. Two predominant histologic subtypes were identified: 14 (26.9%) of 52 had a trabecular or trabecular-glandular cellular pattern with interspersed fibrosis, whereas 38 (73.1%) of 52 had solid architecture. Of the 52, 14 (26.9%) pancreatic neuroendocrine tumors showed at least focal serotonin immunoreactivity. Tumors with predominantly trabecular architecture were significantly more likely to express serotonin than those with solid architecture (P < .01). Only 2 of 34 pancreatic neuroendocrine tumors with fibrosis less than 30% of total tumor area expressed serotonin. The 14 serotonin-expressing tumors were less likely to have lymph node metastases (P = .016) and more likely to involve large pancreatic ducts (P < .01) than were the 38 serotonin-negative tumors. The serotonin-expressing tumors were also found in a younger patient population (P < .01). There was no significant association of serotonin immunoreactivity with Ki-67 proliferation index, tumor size, or distant metastases. Our data demonstrate a strong correlation between trabecular architecture and serotonin immunoreactivity in pancreatic neuroendocrine tumors with stromal fibrosis. Serotonin-expressing tumors are also less likely to have lymph node metastases and more likely to involve large pancreatic ducts.

Subclavian flap aortoplasty: still a safe, reproducible, and effective treatment for infant coarctation.

OBJECTIVE: Subclavian flap repair of infant coarctation has been criticized and in many centers abandoned in favor of resection with end-to-end anastomosis. The goal of this study was to examine intermediate and long-term results of infant subclavian flap aortoplasty, which has been the preferred technique at our institution over the last two decades. METHODS: Our patient database identified all infants (age<1 year) who underwent repair of isthmic coarctation via thoracotomy between January 1984 and December 2004. Procedure details and late results were collected by retrospective review of hospital and clinic data. Follow-up was 95.8% complete at a mean of 6.7 years. RESULTS: Between January 1984 and December 2004, 119 infants underwent isolated subclavian flap repair of coarctation. Mean age and weight at operation were 35+/-52 days (range 1-269 days) and 3.5+/-1.3kg (range 0.7-9.3kg), respectively. Concomitant pulmonary artery banding was performed in 22% (26/119). In-hospital mortality was 4% (5/119) and cumulative late mortality was 6% (7/114) of patients with long-term follow-up. Actuarial survival at 1, 5, and 10 years was 91, 85, and 85%, respectively. Overall re-intervention rate for re-stenosis was 11% (12/114); 10 patients (9%) underwent balloon angioplasty while 3 patients (3%) required operative revision. All re-stenoses occurred in the descending aorta, and all occurred in patients who had undergone neonatal repair. At late follow-up, there were no significant neurologic events (left recurrent laryngeal nerve injury, stellate ganglion dysfunction, or paraplegia), no clinically significant ischemic arm complications, and no flap aneurysms. CONCLUSIONS: Subclavian flap aortoplasty remains our procedure of choice for isthmic coarctation, as it is a simple, technically straightforward technique with a low incidence of re-stenosis and serious early and late morbidity. Furthermore, subclavian flap re-stenoses are easily treated with percutaneous intervention and seldom require surgical re-intervention via thoracotomy.

Adjacent DNA sequences modulate Sox9 transcriptional activation at paired Sox sites in three chondrocyte-specific enhancer elements.

Expression of the type XI collagen gene Col11a2 is directed to cartilage by at least three chondrocyte-specific enhancer elements, two in the 5' region and one in the first intron of the gene. The three enhancers each contain two heptameric sites with homology to the Sox protein-binding consensus sequence. The two sites are separated by 3 or 4 bp and arranged in opposite orientation to each other. Targeted mutational analyses of these three enhancers showed that in the intronic enhancer, as in the other two enhancers, both Sox sites in a pair are essential for enhancer activity. The transcription factor Sox9 binds as a dimer at the paired sites, and the introduction of insertion mutations between the sites demonstrated that physical interactions between the adjacently bound proteins are essential for enhancer activity. Additional mutational analyses demonstrated that although Sox9 binding at the paired Sox sites is necessary for enhancer activity, it alone is not sufficient. Adjacent DNA sequences in each enhancer are also required, and mutation of those sequences can eliminate enhancer activity without preventing Sox9 binding. The data suggest a new model in which adjacently bound proteins affect the DNA bend angle produced by Sox9, which in turn determines whether an active transcriptional enhancer complex is assembled.