Center-specific Data Research Articles

Exploring the Trade-Off between generalist and specialized Models: A center-based comparative analysis for glioblastoma segmentation

IntroductionInherent variations between inter-center data can undermine the robustness of segmentation models when applied at a specific center (dataset shift). We investigated whether specialized center-specific models are more effective compared to generalist models based on multi-center data, and how center-specific data could enhance the performance of generalist models within a particular center using a fine-tuning transfer learning approach. For this purpose, we studied the dataset shift at center level and conducted a comparative analysis to assess the impact of data source on glioblastoma segmentation models. Methods & MaterialsThe three key components of dataset shift were studied: prior probability shift—variations in tumor size or tissue distribution among centers; covariate shift—inter-center MRI alterations; and concept shift—different criteria for tumor segmentation. BraTS 2021 dataset was used, which includes 1251 cases from 23 centers. Thereafter, 155 deep-learning models were developed and compared, including 1) generalist models trained with multi-center data, 2) specialized models using only center-specific data, and 3) fine-tuned generalist models using center-specific data. ResultsThe three key components of dataset shift were characterized. The amount of covariate shift was substantial, indicating large variations in MR imaging between different centers. Glioblastoma segmentation models tend to perform best when using data from the application center. Generalist models, trained with over 700 samples, achieved a median Dice score of 88.98%. Specialized models surpassed this with 200 cases, while fine-tuned models outperformed with 50 cases. ConclusionsThe influence of dataset shift on model performance is evident. Fine-tuned and specialized models, utilizing data from the evaluated center, outperform generalist models, which rely on data from other centers. These approaches could encourage medical centers to develop customized models for their local use, enhancing the accuracy and reliability of glioblastoma segmentation in a context where dataset shift is inevitable.

Outcomes after metabolic and bariatric surgery in preteens versus teens using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database and center-specific data.

The American Academy of Pediatrics (AAP) recently released clinical guidelines for the treatment of childhood obesity, including surgery being appropriate for children 13 years of age and older. The use of this age cut-off was due to a lack of data for children younger than 13. To address this knowledge gap, the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was queried to compare outcomes in preteens to teens after bariatric surgery hypothesizing that there would be no difference in outcomes between the two groups. Patients from the MSAQIP database (2016-2021) were identified and divided into groups <13 years and 13-18 years and were matched using propensity scores based on race, sex, and preoperative BMI. Outcomes were compared including change in BMI, complication rates, 30-day readmission or reoperation, and mortality. Additionally, the centers responsible for the bulk of the preteen patient entries queried their center-specific databases to evaluate weight loss over time. A total of 4755 patients were identified, 47 of whom were <13 years of age. Preteens had similar sex distribution (66% vs. 75% female), were more likely to be Black (27.7% vs. 18.3%) or Hispanic (21.3% vs. 7.6%) race, and weighed less (274 ± 58 vs. 293 ± 85 lb, p = 0.01), but they had similar BMI (46.9 ± 7 vs. 47 ± 13 kg/m2 ) as their teen counterparts. Preteens were more likely to suffer from sleep apnea (34% vs. 19%, p < 0.01) and insulin-dependent type 2 diabetes (10.6% vs. 1.8%, p < 0.01). There were no complications in the preteens compared to teens (0% vs. 0.5%), and they did not undergo any unplanned readmissions (0% vs. 2.9%) or reoperations (0% vs. 0.8%) within 30 days of surgery. There were also no mortalities reported in preteens (0% vs. 0.1%). The risk-adjusted decrease in BMI between preteens and teens was also comparable at 30 days (4.2 [95% CI: 3.0-5.4] vs. 4.6 [95% CI: 4.4-4.7], p = 0.6). Decrease in BMI in preteens was 7 ± 3 kg/m2 at 3 months and 9 ± 4 kg/m2 at 12 months after surgery, which represented a percentage BMI change of 16 ± 7 and 20 ± 8, respectively. This study demonstrates that bariatric surgery in preteens is safe and efficacious when performed at specialized centers, and that age criteria may not be required. The AAP and others are encouraged to include age cut-offs in their guidelines for children with obesity and bariatric surgery only when data are available to support their inclusion.

Outcomes of a Diagnostic Pathway for Prostate Cancer Based on Biparametric MRI and MRI-Targeted Biopsy Only in a Large Teaching Hospital.

Diagnostic pathways for prostate cancer (PCa) balance detection rates and burden. MRI impacts biopsy indication and strategy. A prospectively collected cohort database (N = 496) of men referred for elevated PSA and/or abnormal DRE was analyzed. All underwent biparametric MRI (3 Tesla scanner) and ERSPC prostate risk-calculator. Indication for biopsy was PIRADS ≥ 3 or risk-calculator ≥ 20%. Both targeted (cognitive-fusion) and systematic cores were combined. A hypothetical full-MRI-based pathway was retrospectively studied, omitting systematic biopsies in: (1) PIRADS 1-2 but risk-calculator ≥ 20%, (2) PIRADS ≥ 3, receiving targeted biopsy-cores only. Significant PCa (GG ≥ 2) was detected in 120 (24%) men. Omission of systematic cores in cases with PIRADS 1-2 but risk-calculator ≥ 20%, would result in 34% less biopsy indication, not-detecting 7% significant tumors. Omission of systematic cores in PIRADS ≥ 3, only performing targeted biopsies, would result in a decrease of 75% cores per procedure, not detecting 9% significant tumors. Diagnosis of insignificant PCa dropped by 52%. PCa undetected by targeted cores only, were ipsilateral to MRI-index lesions in 67%. A biparametric MRI-guided PCa diagnostic pathway would have missed one out of six cases with significant PCa, but would have considerably reduced the number of biopsy procedures, cores, and insignificant PCa. Further refinement or follow-up may identify initially undetected cases. Center-specific data on the performance of the diagnostic pathway is required.

GEospatial aNalysis of ExtRacorporeal membrane oxygenATion in Europe (GENERATE)

A cross-sectional survey GENERATE (GEospatial aNalysis of ExtRacorporeal membrane oxygenATion in Europe) initiated on behalf of the European chapter of the Extracorporeal Life Support Organization (EuroELSO), aims to provide a systematic, detailed description of contemporary Extracorporeal Life Support (ECLS) provision in Europe, map the spatial distribution of ECLS centers, and the accessibility of ECLS. Structured data collection forms were used to create a narrative description of ECLS provision in EuroELSO affiliated countries. This consisted of both center-specific data and relevant national infrastructure. Data was provided by a network of local and national representatives. Spatial accessibility analysis was conducted where appropriate geographical data were available. 281 centers from 37 countries affiliated to EuroELSO were included in the geospatial analysis and demonstrate heterogeneous patterns of ECLS provision. Accessibility of ECLS services within 1 hour of drive-time is available for 50% of the adult population in 8 of 37 countries (21.6%). This proportion is reached within 2hours in 21 of 37 countries (56.8%) and within 3hours in 24 of 37 countries (64.9%). For pediatric centers, accessibility is similar with 9 of 37 countries (24.3%) reached the covering of 50% of the population aged 0-14 within 1hour and 23 of 37 countries (62.2%) within 2hours and 3hours. ECLS services are accessible in most of the European countries, but their provision differs across the continent. There is still no solid evidence given regarding the optimal ECLS provision model. The spatial disparity in ECLS provision demonstrated in our analysis requires governments, healthcare professionals and policy makers to consider how to develop existing provision to accommodate the anticipated increase in need for time critical access to this advanced support modality.

Major Perioperative Complications of Benign Gynecologic Procedures at a University-Affiliated Hospital

Background: With the increasing use of minimally invasive techniques for gynecologic procedures, women are at a low risk for peri-operative complications. The purpose of this study was to determine the incidence of and risk factors for major intra or postoperative complications among women undergoing benign gynecologic surgeries. Methods: We conducted a retrospective observational study of all women who underwent benign gynecologic surgery in 2016-2017 at a University-Affiliated community hospital. Pregnant women, malignancy cases, and hysteroscopic or minor vulvar procedures were excluded. Primary outcome was composite intraoperative and/or 30-day postoperative complications requiring medical or surgical management. Logistic regression identified significant patient, peri-operative and surgeon risk factors associated with complications. Results: Of 975 patients included, 53 patients experienced major intra or postoperative complications (5.4%). Mean age was 47.7 ± 13.8 years. Mean BMI was 27.1 ± 5.8 kg/m2. Prior abdominal surgery (laparotomy or laparoscopy) (adjusted odds ratio [OR]= 2.01, 95%CI 1.05-3.83) and emergency surgery (adjusted OR= 19.54, 95%CI 2.99-127.54) were significantly associated with major complications. Surgeon volume of 1-2 operative days per month (adjusted OR=0.30, 95%CI 0.10 - 0.87) and age 40-64 years (adjusted OR=0.24, 95%CI 0.11- 0.56) had a protective effect on the risk of major complications. Conclusions: Among patients in our sample, 5.4% experienced major complications from a benign gynecologic surgery. Complications from benign gynecologic surgery are rare, even in the absence of robotic equipment. Center-specific data and a discussion of the increased morbidity associated with with prior abdominal surgery and emergency surgery should be considered for pre-operative patient counselling.

Reusable, Single-Use, or Both: A Cost Efficiency Analysis of Flexible Ureterorenoscopes After 983 Cases.

Objectives: To determine which flexible ureterorenoscopy program would be most cost-efficient in our center, a cost efficiency analysis and a formula to assess cost efficiency feasibility of a hybrid model were performed. Methods: Total cost per case of reusable flexible ureterorenoscopes (rfURS) was retrospectively calculated and compared with two single-use flexible ureterorenoscopes (sufURS) marketed. A mathematical formula was developed from our data to identify the necessary increase of use of rfURS (NIU-rfURS) to be cost-efficient in a hybrid system utilizing sufURS for only high-risk-of-breakage cases. Results: In 57 months, 983 procedures were performed using 4 digital rfURS (Flex-XC; Storz), necessitating 45 repairs, with a total repair cost of €256.809. Including the capital investment of €24.000 per scope and €60 per sterilization cycle, the cost per case averaged €419 after 983 cases. Consistently using sufURS would have cost 55% to 127% more (respectively, Uscope PU3022® and Lithovue® at €650 and €950 manufacturer suggested retail price). On a per case analysis, the cost was initially extremely high, but declined to reach a plateau around €480 after ∼400 cases. After 155 or 274 procedures, a rfURS program appeared more cost-efficient than consistently using Lithovue or Uscope PU3022, respectively. Based on our data and formula, if we would hypothetically use Uscope PU3022 or Lithovue for 15% of the cases, the NIU-rfURS is, respectively, 28% or 74% (∼6 or 16 cases). The NIU-rfURS increases exponentially with an increased use of sufURS. Conclusion: Consistently using rfURS is more cost-efficient than the constant use of sufURS after 155 to 274 cases. We describe the first mathematical formula that allows a calculation and feasibility assessment of using both reusable and disposable fURS. To identify whether a hybrid system may be a feasible cost-efficient alternative to a rfURS-only program, any center can calculate the NIU-rfURS by entering center-specific data in the formula.

Kidney allograft rejection: Diagnosis and treatment practices in USA- A UNOS survey.

We studied diverse rejection management strategies across centers by conducting a UNOS survey of kidney transplant program directors in 2017. There were 104 total responses from 235 kidney transplant programs representing 88 unique transplant programs (response rate 37%). Information was collected on center-specific management practices. Pertinent center-specific data were obtained from the OPTN database. Of the respondents, 33% were considered large centers (>100 transplants/year). Thymoglobulin was the most commonly used induction agent at 84%, 72% responders do rapid steroid withdrawal, and mycophenolic acid (MPA) is the major antimetabolite (100%). For diagnosing TCMR, 100% used indication biopsy, 28% used protocol biopsy, 2% used serum biomarkers, and none used urine cytokines. For ABMR, 99% used indication biopsy, 34% used protocol biopsy, 72% used DSA, 21% used C1q positive DSA, and none used gene profiling (ENDATS). The treatment of subclinical and clinical TCMR included iv/PO steroids. PP/IVIG were the commonest treatments for ABMR. The use of rituximab, bortezomib, and eculizumab increased from C4D-ABMR to recurrent ABMR. There are diverse management practices for diagnosing and treating rejection. An effort to harmonize these diverse practices for management of TCMR and ABMR will give an opportunity to pool data for evaluating clinical outcomes.

An audit & feedback intervention for improved anticoagulant use in patients with atrial fibrillation in primary care

BackgroundImproving use of anticoagulants in atrial fibrillation (AF) patients in primary care has proved challenging. Anticoagulants are often prescribed by primary care physicians in the long term. Suboptimal anticoagulant use may be partly due to physicians' non-prescribing. One potential way of targeting physician prescribing behavior is “audit & feedback”. The documented use of audit and feedback in research aimed at increasing use of anticoagulants in primary care is limited. The objective was to test if an audit & feedback intervention aimed at directors in primary care centers could increase the use of anticoagulants in patients with AF. MethodsDatabase generated quality reports with primary care center specific data on recommended medication use in their patients with previous stroke or atrial fibrillation were sent to intervention centers. Results94 centers received the intervention, 102 centers were controls. 31,477 patients in total were included. Use of anticoagulants in all primary care centers increased from 76% before to 82% after the intervention. Patients in intervention centers were more likely than patients in control centers to use anticoagulants after the intervention, adjusted odds ratio increasing slightly from 1.04 (95%, CI, 0.98–1.10) before to 1.08 (95% CI, 1.02–1.15) after the intervention. ConclusionsAn audit & feedback intervention with quality reports in primary care had only a small effect on anticoagulant use in patients with AF. A combined and more complex intervention may have a greater effect in improving anticoagulation use.

Retrospective study evaluating the performance of risk factors for invasive mold infections in liver transplantation

Mold infections in liver transplant are associated with high mortality. Guidelines recommend prophylaxis targeted against mold based upon risk factors of fulminant hepatic failure, retransplantation, reoperation, and renal replacement therapy post-transplant. It is not known if these factors identify risk of mold infection at every center. A retrospective study was conducted of adult liver transplant recipients at a single center from 2010 to 2014. The association between risk factors and invasive mold infection and effect of antifungal prophylaxis were determined. Five hundred thirty-four liver transplant recipients were identified. The overall incidence of invasive mold infection was 0.9% (N=5). The incidence in patients with (N=128) and without (N=406) risk factors was 0.78% and 0.98%, respectively. Antifungal prophylaxis with mold activity was administered to 23/128 (18%) with risk factors, and none developed infection. No mold-active prophylaxis was given to 105/128 (82%) with risk factors, and incidence of mold infection was 0.95% (N=1). Number needed to treat was 105. Traditional risk factors for mold infection in liver transplant performed poorly. These results underscore the importance of transplant center-specific data to inform adoption of an antifungal prophylactic strategy. Studies are needed to determine alternative risk factors to facilitate appropriate targeting of antifungals.

Most pediatric transplant centers are low volume, adult-focused, and in proximity to higher volume pediatric centers

BackgroundIndependent studies provide evidence that low volume pediatric solid organ transplant centers have inferior outcomes compared to high volume pediatric centers. The study assessed whether patients treated at low volume pediatric centers have access to higher volume pediatric centers, which offer potentially better outcomes. MethodsWe analyzed center specific data on 467 pediatric solid organ transplant centers in the U.S using the Organ Procurement and Transplantation Network database from 2002 to 2014. The proximities of low volume pediatric centers to high volume pediatric centers were determined using Maptive, a tool based on Google Maps. ResultsMost low volume pediatric transplant centers focused on transplantation of adults (84% heart, 83% liver, and 93% kidney programs). A majority of low volume pediatric centers (77% for heart, 53% for lung, 68% for liver and 90% for kidney) were within 150 miles of high volume centers. Among all children listed for transplantation, 30.7% were listed in low volume pediatric centers. Most low volume pediatric centers are adult focused and near high volume pediatric centers. ConclusionWe need greater scrutiny of outcomes, particularly waitlist outcomes, of low volume pediatric solid organ transplant centers located close to high volume pediatric solid organ transplant centers. Type of Study and Level of EvidenceRetrospective Comparative Study, Level III.

Deep learning-based preoperative predictive analytics for patient-reported outcomes following lumbar discectomy: feasibility of center-specific modeling

Background ContextThere is considerable variability in patient-reported outcome measures following surgery for lumbar disc herniation. Individualized prediction tools that are derived from center- or even surgeon-specific data could provide valuable insights for shared decision-making. PurposeTo evaluate the feasibility of deriving robust deep learning-based predictive analytics from single-center, single-surgeon data. Study DesignDerivation of predictive models from a prospective registry. Patient SamplePatients who underwent single-level tubular microdiscectomy for lumbar disc herniation. Outcome MeasuresNumeric rating scales for leg and back pain severity and Oswestry Disability Index scores at 12 months postoperatively. MethodsData were derived from a prospective registry. We trained deep neural network-based and logistic regression-based prediction models for patient-reported outcome measures. The primary endpoint was achievement of the minimum clinically important difference (MCID) in numeric rating scales and Oswestry Disability Index, defined as a 30% or greater improvement from baseline. Univariate predictors of MCID were also identified using conventional statistics. ResultsA total of 422 patients were included (mean [SD] age: 48.5 [11.5] years; 207 [49%] female). After 1 year, 337 (80%), 219 (52%), and 337 (80%) patients reported a clinically relevant improvement in leg pain, back pain, and functional disability, respectively. The deep learning models predicted MCID with high area-under-the-curve of 0.87, 0.90, and 0.84, as well as accuracy of 85%, 87%, and 75%. The regression models provided inferior performance measures for each of the outcomes. ConclusionsOur study demonstrates that generating personalized and robust deep learning-based analytics for outcome prediction is feasible even with limited amounts of center-specific data. With prospective validation, the ability to preoperatively and reliably inform patients about the likelihood of symptom improvement could prove useful in patient counselling and shared decision-making.

Recipient characteristics and morbidity and mortality after liver transplantation

Over the last decade, liver transplantation of sicker, older non-hepatitis C cirrhotics with multiple co-morbidities has increased in the United States. We sought to identify an easily applicable set of recipient factors among HCV negative adult transplant recipients associated with significant morbidity and mortality within five years after liver transplantation. We collected national (n = 31,829, 2002-2015) and center-specific data. Coefficients of relevant recipient factors were converted to weighted points and scaled from 0-5. Recipient factors associated with graft failure included: ventilator support (five patients; hazard ratio [HR] 1.59; 95% CI 1.48-1.72); recipient age >60 years (three patients; HR 1.29; 95% CI 1.23-1.36); hemodialysis (three patients; HR 1.26; 95% CI 1.16-1.37); diabetes (two patients; HR 1.20; 95% CI 1.14-1.27); or serum creatinine ≥1.5 mg/dl without hemodialysis (two patients; HR 1.15; 95% CI 1.09-1.22). Graft survival within five years based on points (any combination) was 77.2% (0-4), 69.1% (5-8) and 57.9% (>8). In recipients with >8 points, graft survival was 42% (model for end-stage liver disease [MELD] score <25) and 50% (MELD score 25-35) in recipients receiving grafts from donors with a donor risk index >1.7. In center-specific data within the first year, subjects with ≥5 points (vs. 0-4) had longer hospitalization (11 vs. 8 days, p <0.01), higher admissions for rehabilitation (12.3% vs. 2.7%, p <0.01), and higher incidence of cardiac disease (14.2% vs. 5.3%, p <0.01) and stage 3 chronic kidney disease (78.6% vs. 39.5%, p = 0.03) within five years. The impact of co-morbidities in an MELD-based organ allocation system need to be reassessed. The proposed clinical tool may be helpful for center-specific assessment of risk of graft failure in non-HCV patients and for discussion regarding relevant morbidity in selected subsets. Over the last decade, liver transplantation of sicker, older patient with multiple co-morbidities has increased. In this study, we show that a set of recipient factors (recipient age >60 years, ventilator status, diabetes, hemodialysis and creatinine >1.5 mg/dl) can help identify patients that may not do well after transplant. Transplanting sicker organs in patients with certain combinations of these characteristics leads to lower survival.

Red cell transfusions as an independent risk for mortality in critically ill children.

BackgroundSeverity of illness is an important consideration in making the decision to transfuse as it is the sicker patient that often needs a red cell transfusion. Red blood cell (RBC) transfusions could potentially have direct effects and interact with presenting illness by contributing to pathologies such as multi-organ dysfunction and acute lung injury thus exerting a considerable impact on overall morbidity and mortality. In this study, we examine if transfusion is an independent predictor of mortality, or if outcomes are merely a result of the initial severity as predicted by Pediatric Risk of Mortality (PRISM) III, Pediatric Index of Mortality (PIM2), and day 1 Pediatric Logistic Organ Dysfunction (PELOD) scores.MethodsA single center retrospective study was conducted using data from a prospectively maintained transfusion database and center-specific data at our pediatric ICU between January 2009 and December 2012. Multivariate regression was used to control for the effects of clinical findings, therapy, and severity scores, with mortality as the dependent variable. Likelihood ratios and area under the curve were used to test the fidelity of severity scores by comparing transfused vs. non-transfused patients.ResultsThere were 4975 admissions that met entry criteria. In multivariate analysis, PRISM III scores and serum hemoglobin were significant predictors of transfusion (p < 0.05). Transfused and non-transfused subjects were distinctly disparate, so multivariate regression was used to control for differences. Severity scores, age, volume transfused, and vasoactive agents were significantly associated with mortality whereas hemoglobin was not. A substantial number of transfusions (45 %) occurred in the first 24 h, and patients transfused later (24–48 h) were more likely to die compared to this earlier time point. Likelihood ratio testing revealed statistically significant differences in severity scoring systems to predict mortality in transfused vs. non-transfused patients.ConclusionsThis study suggests that RBC transfusion is an important risk factor that is statistically independent of severity. The timing of transfusions that related strongest to mortality remained outside the purview of severity scoring, as these happened beyond the timing of data collection for most scoring systems.

Familial dilated cardiomyopathy diagnosis is commonly overlooked at the time of transplant listing

The prevalence and clinical characteristics of familial dilated cardiomyopathy (FDCM) among patients with end stage heart failure (ESHF) has yet to be elucidated. We sought to determine the prevalence of FDCM in ESHF in the United Network for Organ Sharing (UNOS) registry and compare this with center specific data from a large tertiary teaching hospital. Patients with a banked UNOS diagnosis of dilated cardiomyopathy (DCM) whose care originated at our center then underwent detailed pedigree analysis in order to determine the true prevalence of FDCM. A total of 16,091 patients with DCM from all centers were identified in the UNOS registry of whom 492 carried the diagnosis of FDCM (3.1%). Patients with the diagnosis of FDCM tended to be younger (42 versus 49 years old in idiopathic dilated cardiomyopathy (IDCM), p=0.001), were less likely to have diabetes (7.8% versus 16.5% in IDCM, p<0.0001), had slightly lower creatinine (1.2 versus 1.4 in IDCM, p=0.0001) and were more likely to have a panel reactive antibody level ≥ 20% (62.1% versus 44.7% in IDCM, p<0.0001). Consecutive living adult patients with ESHF were identified from the UNOS registry that had been treated at the Yale Center for Advanced Heart Failure (YCAHF). After excluding all diagnoses that did not include any form of non-ischemic DCM, 73 patients met the inclusion criteria. Center-specific UNOS data showed pre-pedigree analysis diagnosis of FDCM in 4.12% of patients (3 out of 73), consistent with that found in the UNOS database for all centers. However, after detailed family history and pedigree analysis, 19 (26%) of 73 patients were found to have FDCM, while the remaining 54 were found to have IDCM. Echocardiographic findings including mitral regurgitation, mitral valve annulus and left ventricular end diastolic dimension were not significantly different between groups when adjusting for multiple testing. The diagnosis of FDCM was missed in the majority of patients with end stage heart failure enrolled in the UNOS database, as sampled from a large, tertiary care teaching hospital in the United States. Echocardiographic findings are unlikely to aid in the differentiation between DCM and FDCM. Detailed pedigree analysis can successfully identify undiagnosed FDCM and should be encouraged prior to transplant listing as it has important implications for early detection and treatment of disease in family members.

Assessing the impact of the new kidney allocation system on rates of transplantation for highly sensitized recipients – Center specific data

Background The new OPTN/UNOS kidney allocation system (KAS) is designed to expand donor access for highly-HLA sensitized patients (HS). Our approach to transplanting the HS patients (PTS) awaiting deceased donor (DD) transplants (TXP) is to assign unacceptable antigens (UA) based on 4 antibody testing methods and to desensitize PTS using high dose IVIG and Rituximab. In the past, we would assign priority based on wait time and likelihood of receiving DD offers. Aim The aim of our study was to assess the impact of the new KAS on TXP rates for PTS with varying levels of sensitization compared to non-sensitized PTS. We examined PTS who are HS (99/100CPRA), moderately sensitized (80–98 CPRA) and less sensitized ( 20CPRA). Methods UAs are assigned based on 4 methods luminex single antigen with and without dilution, C1Q assay and CDC. Final crossmatches are performed by Flow and CDC. Patient’s antibody history, CPRA and crossmatch results were tabulated for this study. Rates of deceased donor TXP for a period of 144 days prior to and after December 7, 2014 were analyzed. Results The rate of transplantation for PTS in the 99–100% CPRA group was the same in both time periods. The number of deceased donor TXP in the 80–98% and 20–79% CPRA groups was reduced by 50%. However the number of TXP for PTS in 0–19% CPRA was increased by 50%. Conclusions While the rate of deceased donor TXP for PTS in 99–100% CPRA at our center remained the same at ∼ 12.7%, it increased from 2.5% to 17.7% for the national average. The new KAS appears to reduce the chance of transplantation for moderately sensitized recipients and increases the number of TXP for non-sensitized recipients at our center. The KAS appears to have little impact on transplanting the highly sensitized PTS at a center with progressive assignment of UAs and a desensitization program. Download : Download full-size image

The new kidney allocation system-who are we penalizing?

The new kidney allocation system implemented at the end of 2014 attributes additional allocation points to sensitized patients using a sliding cPRA scale. In addition patients with > 98% cPRA receive regional/national allocation priority due to their high level of sensitization. Unfortunately,the new allocation system does not allow for the input of HLA-DQA and HLA-DP unacceptable antigens for the computation of cPRA. To assess the number of patients affected by the lack of programming for HLA-DQA and -DP, we reviewed the antibody data of our adult kidney waitlist population composed of 485 patients. We found that 7.6% of our patients had HLA-DP and/or HLA-DQA antibodies with MFI values > 3000 for which they were not receiving additional allocation points due to our inability to enter HLA-DQA and -DP specificities as unacceptable antigens. The vast majority of the affected patients (86.5%) had HLA-DP antibodies and cPRA of 98%. In fact 75.7% of patients with HLA-DQA or HLA-DP antibodies had cPRA of 98% while 24.3% had cPRA > 98% and thus were eligible for regional/national priority. Our gathered data strongly advocates the implementation of new allocation software allowing for the listing of HLA-DQA and HLA-DP unacceptable antigens and for computation of these unacceptable antigens in the cPRA. Per OPTN data as of 4/22/15 there were 123,193 people waiting for a kidney transplant in the US. Using our center specific data on a national scale, it means that 9300 people are not receiving allocation points for unacceptable antigens against HLA-DP and/or -DQA. Our data also supports the implementation of mandatory typing of donors for HLA-DP and DQA since 24.3% of patients with HLA-DQA and -DP antibodies have cPRA > 98%. Mandatory typing of donors for HLA-DP and -DQA would allow for faster organ allocation and unnecessary shipment of organ for regional/national share to patient having unacceptable HLA-DQA or -DP antibodies.

Racial and ethnic disparities in access to and utilization of living donor liver transplants.

Living donor liver transplantation (LDLT) is a comparable alternative to deceased donor liver transplantation and can mitigate the risk of dying while waiting for transplant. Although evidence exists of decreased utilization of living donor kidney transplants among racial minorities, little is known about access to LDLT among racial/ethnic minorities. We used Organ Procurement and Transplantation Network/United Network for Organ Sharing data from February 27, 2002 to June 4, 2014 from all adult liver transplant recipients at LDLT-capable transplant centers to evaluate differential utilization of LDLTs based on race/ethnicity. We then used data from 2 major urban transplant centers to analyze donor inquiries and donor rule-outs based on racial/ethnic determination. Nationally, of 35,401 total liver transplant recipients performed at a LDLT-performing transplant center, 2171 (6.1%) received a LDLT. In multivariate generalized estimating equation models, racial/ethnic minorities were significantly less likely to receive LDLTs when compared to white patients. For cholestatic liver disease, the odds ratios of receiving LDLT based on racial/ethnic group for African American, Hispanic, and Asian patients compared to white patients were 0.35 (95% CI, 0.20-0.60), 0.58 (95% CI, 0.34-0.99), and 0.11 (95% CI, 0.02-0.55), respectively. For noncholestatic liver disease, the odds ratios by racial/ethnic group were 0.53 (95% CI, 0.40-0.71), 0.78 (95% CI, 0.64-0.94), and 0.45 (95% CI, 0.33-0.60) respectively. Transplant center-specific data demonstrated that African American patients received fewer per-patient donation inquiries than white patients, whereas fewer African American potential donors were ruled out for obesity. In conclusion, racial/ethnic minorities receive a disproportionately low percentage of LDLTs, due in part to fewer initial inquiries by potential donors. This represents a major inequality in access to a vital health care resource and demands outreach to both patients and potential donors.

Bacterial infection after liver transplantation.

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.

Clinical process analysis: Embedding performance improvement skills for measurable and sustainable change.

67 Background: The Clinical Process Analysis methodology, based on Time Driven Activity Based Costing (Kaplan), aligns data reporting with frontline processes to drive improvement in clinical quality and financial performance. After the completion of 6 ambulatory centers (with 6 in progress), the program evolved to include a Performance Improvement (PI) Phase. The goal: embed PI skills in all clinical operations; provide resources for PI project initiation, facilitation, and sustainability; and continue collaboration with MD Anderson Cancer Center process owners through measurable improvement in safety, timeliness, effectiveness, efficiency, equity and patient-centeredness. (IOM 2001). Methods: The center and the CPA Team utilize institutional dashboards and multiple data resources to establish the project scope. The scope is converted to a Blueprint which outlines a timeline of the project, a list of required resources, and center-specific data. The CPA Team interviews frontline staff, clinical leadership and financial teams to create a current state process flow chart. Opportunities for Improvement (OFI), operational and clinical variations, cycle times and other management reporting metrics are included on the charts, as well as patient experience audio, as gathered by an MD Anderson marketing team. OFIs are evaluated, categorized, and prioritized by clinical leadership, and the CPA Team works with the center’s designated PI team to develop and implement Quick Fixes, PDSA and more extensive projects. Results: In 6 completed ambulatory centers in FY13: 176 Opportunities for Improvement, $936,463 Savings. Summary reports provide direct labor costs and estimated times, per resource type, for center activities. Per MDs, managers, staff and financial experts, other uses for process flow charts include: tracking patient flow; resource utilization; customer satisfaction; patient education; and on-boarding staff. Conclusions: In FY14, the CPA Program will focus on patient access in 15 centers, gathering data to identify trends and common themes to implement Best Practices across the institution.

Evolution of Trends in the Live Kidney Transplant Donor-Recipient Relationship

ObjectiveThis study examined the changing demographics and age profile between living donors and their recipients. A 46-year review of living donor renal transplants in a single transplant center was performed. PatientsThe study included 923 consecutive living donor renal transplants from January 1966 until December 2011. ResultsThese 923 living donor kidneys transplants represent 41% of all transplants performed during this 46-year review. The majority involved sibling donation (39.5%) followed by parent to child (32.5%). Dividing the 46-year timeframe into quartiles, the mean age of donors has remained stable at 39.3 ± 10.9 years. In contrast, the mean age of recipients has trended upwards, from 28 ± 10.7 years in the first quartile (1966–1978) to 37 ± 17.5 years in the latest quartile (2001–2011). This represents an increase every year of approximately 4 months (P < .001). Over the same period, the difference between a given donor's age and their recipient's has decreased every year by approximately 4 months (P < .001). In a linear regression model of donor-recipient categories and their age difference over time, we found that both the child-to-parent and grandchild-to-grandparent groups had the largest effect on the donor-recipient age difference when compared to the classic parent-to-child relationship. ConclusionThis review of center-specific data shows that the difference in the age of the donor to their recipient has been narrowing over time. We have determined that this is primarily due to changes in donor-recipient demographics with an increasing number of younger donors to older recipients. Although the medical risks to donors living with a single kidney have yet to be shown different than that of the general population, the increasing volume of donors who are younger and those with no relation to the recipient should prompt closer follow-up within the transplantation medical community.