A model for calculating the long-term estimated post-transplant survival of deceased donor liver transplant patients

BACKGROUND

The estimated long-term survival (EPTS) score is used for kidney allocation. A comparable prognostic tool to accurately quantify EPTS benefit in deceased donor liver transplant (DDLT) candidates is nonexistent.

METHODS

Using the Scientific Registry of Transplant Recipients (SRTR) database, we developed, calibrated, and validated a nonlinear regression equation to calculate liver-EPTS (L-EPTS) for 5- and 10-year outcomes in adult DDLT recipients. The population was randomly split (70:30) into two discovery (N = 26,372 and N = 46,329) and validation cohorts (N = 11,288 and N = 19,859) for 5- and 10-year post-transplant outcomes, respectively. Discovery cohorts were used for variable selection, Cox proportional hazard regression modeling, and nonlinear curve fitting. Eight clinical variables were selected to construct the L-EPTS formula, and a five-tiered ranking system was created.

FINDINGS

Tier thresholds were defined and the L-EPTS model was calibrated (R² = 0.96 [5-year] and 0.99 [10-year]). Patients' median survival probabilities in the discovery cohorts for 5- and 10-year outcomes ranged from 27.94% to 89.22% and 16.27% to 87.97%, respectively. The L-EPTS model was validated via calculation of receiver operating characteristic (ROC) curves using validation cohorts. Area under the ROC curve was 82.4% (5-year) and 86.5% (10-year).

INTERPRETATION

L-EPTS has high applicability and clinical utility because it uses easily obtained pre-transplant patients characteristics to accurately discriminate between those who are likely to receive a prolonged survival benefit and those who are not. It is important to evaluate medical urgency alongside survival benefit and placement efficiency when considering the allocation of a scarce resource.

FUNDING

There are no funding sources related to this project.

Contribution of Estimates of Glomerular Filtration to the Extensive Disparities in Preemptive Listing for Kidney Transplant

Introduction

The use of race coefficients in equations for estimated glomerular filtration rate (eGFR) may have contributed to racial disparities in access to preemptive (without dialysis exposure) kidney transplantation (Ktx).

Methods

In this retrospective national cohort study of incident kidney transplant candidates in the United States from 2001 to 2019, we describe temporal trends and racial disparities in preemptive listing and the distribution of eGFR at listing, using eGFR as reported and after removing the race coefficient for Black candidates.

Results

Among 511,686 candidates, preemptive listing increased over time, from 18% in 2001 to 33% in 2019. Non-Black candidates were listed preemptively nearly twice as frequently as Black candidates in 2019 (38% vs. 21% preemptive) and at higher eGFR values (median 15.6 vs. 15.0 ml/min per 1.73 m²). After adjusting for candidate characteristics, including listing eGFR without the race coefficient, preemptive Black candidates still had significantly lower odds of preemptive deceased donor (DD) kidney transplantation compared to non-Black candidates (odds ratio 0.87, 95% confidence interval: 0.78-0.98).

Conclusions

Over the last 2 decades, Black patients were consistently less likely to be listed preemptively and were listed at lower eGFR values. Adjusting for listing eGFR with the race coefficient computationally removed did not eliminate the racial disparity, suggesting that additional efforts are needed to achieve equity in preemptive transplantation beyond adopting race-free eGFR equations.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

Children from socioeconomically disadvantaged communities present in more advanced heart failure at the time of transplant listing

Transplant registries in the US do not collect information about community level risk factors. We utilized a community level socio-economic risk indicator, the distressed communities' index to understand its association with clinical presentation among children listed for heart transplant (HT). We found that currently, majority (40%) of children listed from distressed communities are Black. On multivariable analysis, compared to children from prosperous communities, those from distressed communities listed for HT were significantly more likely to be Status 1A (adjusted odds ratio [aOR] 1.39) and on a ventricular assist device (aOR 1.44). Compared to White children from prosperous communities, both Black and White children from distressed communities were more likely to be listed Status 1A (aOR 2.1 and 1.36 respectively) and have renal dysfunction (aOR 1.71 and 1.52 respectively). In conclusion, heart failure severity at listing appears more likely associated with community-level risk factors and less so with child's race/ethnicity.

Dysnatremias, Mortality, and Kidney Failure in CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

Rationale & Objective

Dysnatremias have been associated with an increased risk of mortality in the chronic kidney disease (CKD) population. Our objective is to identify the prevalence of and risk factors associated with dysnatremias in a CKD population and assess the association of dysnatremias with kidney failure and mortality among patients with CKD enrolled in the Chronic Renal Insufficiency Cohort Study.

Study Design

Analysis of prospective cohort study.

Setting & Participants

Adult patients aged 21-74 years with CKD from the Chronic Renal Insufficiency Cohort study.

Predictors

Baseline and time-dependent hyponatremia and hypernatremia.

Outcomes

All-cause mortality and kidney failure.

Analytical Approach

Baseline characteristics were compared using χ2 tests for categorical variables, analysis of variance for age, and Kruskal-Wallis tests for laboratory variables. Cox proportional hazards models and competing risk models were used to evaluate the association between baseline sodium level and overall mortality.

Results

Of a total of 5,444 patients with CKD, 486 (9%) had hyponatremia and 53 (1%) had hypernatremia. Altogether, 1,508 patients died and 1,206 reached kidney failure. In adjusted Cox models, time-dependent dysnatremias were strongly associated with mortality for both hyponatremia (HR, 1.38; 95% CI, 1.16-1.64) and hypernatremia (HR, 1.54; 95% CI, 1.04-2.29). Factors associated with hyponatremia included female sex, diabetes, and hypertension. Regardless of age, time-dependent hypernatremia was associated with an increased risk of kidney failure (HR, 1.64; 95% CI, 1.06-2.53). Baseline and time-dependent hyponatremia were associated with an increased risk of kidney failure in patients younger than 65 (baseline hyponatremia HR, 1.30; 95% CI, 1.03-1.64 and time-dependent hyponatremia HR, 1.36; 95% CI, 1.09-1.70) but not among patients aged >65 years.

Limitations

Inability to establish causality and lack of generalizability to hospitalized patients.

Conclusions

Dysnatremias are prevalent among ambulatory CKD patients and are associated with mortality and kidney failure. Time-dependent dysnatremias were significantly associated with mortality in patients with CKD. Time-dependent hypernatremia was associated with progression to kidney failure. Baseline and time-dependent hyponatremia were associated with an increased risk of progression to kidney failure in those younger than 65 years.

Geographic hot spots of kidney transplant candidates wait-listed post-dialysis

INTRODUCTION

Preemptive wait-listing of deceased donor kidney transplant (DDKT) candidates before maintenance dialysis increases the likelihood of transplantation and improves outcomes among transplant patients. Previous studies have identified substantial disparities in rates of preemptive listing, but a gap exists in examining geographic sources of disparities, particularly for sub-regional units. Identifying small area hot spots where delayed listing is particularly prevalent may more effectively inform both health policy and regionally appropriate interventions.

METHODS

We conducted a retrospective cohort study utilizing 2010-2020 Scientific Registry of Transplant Recipients (SRTR) data for all DDKT candidates to examine overall and race-stratified geospatial hot spots of post-dialysis wait-listing in U.S. zip code tabulation areas (ZCTA). Three geographic clustering methods were utilized to identify robust statistically significant hot spots of post-dialysis wait-listing.

RESULTS

Novel sub-regional hot spots were identified in the southeast, southwest, Appalachia, and California, with a majority existing in the southeast. Race-stratified results were more nuanced, but broadly reflected similar patterns. Comparing transplant candidates in hot spots to candidates in non-clusters indicated a strong association between residence in hot spots and high area deprivation (OR: 6.76, 95%CI: 6.52-7.02), indicating that improving access healthcare in these areas may be particularly beneficial.

CONCLUSION

Our study identified overall and race-stratified hot spots with low rates of preemptive wait list placement in the U.S., which may be useful for prospective healthcare policy and interventions via targeting of these narrowly defined geographical areas.

Place-based heterogeneity in lung transplant recipient outcomes

Place is defined as a social or environmental area of residence with meaning to a patient. We hypothesize there is an association between place and the clinical outcomes of lung transplant recipients in the United States. In a retrospective cohort study of transplants between January 1, 2010, and December 31, 2019, in the Scientific Registry of Transplant Recipients, multivariable Cox regression models were used to test the association between place (through social and environmental factors) with readmission, lung rejection, and survival. Among 18,465 recipients, only 20% resided in the same county as the transplant center. Recipients from the most socially vulnerable counties when compared to the least vulnerable were more likely to have COPD as a native disease, Black or African American race, and travel long distances to reach a transplant center. Higher local life expectancy was associated with lower likelihood for readmission (odds ratio [OR] = 0.90, 95% confidence interval [CI]: 0.84, 0.98, p = .01). Higher social vulnerability was associated with a higher likelihood of lung rejection (OR = 1.37, [CI]: 1.07, 1.76, p = .01). There was no association of residence with posttransplant survival. Recipient place-based factors were associated with complications and processes of care after transplant and warrant further investigation.

HLA-DQ Mismatches Lead to More Unacceptable Antigens, Greater Sensitization, and Increased Disparities in Repeat Transplant Candidates

BACKGROUND

In single-center studies, HLA-DQ mismatches stimulate the most pathogenic donor-specific antibodies. However, because of limitations of transplant registries, this cannot be directly confirmed with registry-based analyses.

METHODS

We evaluated patients in the Scientific Registry of Transplant Recipients who were relisted after renal graft failure with new, unacceptable antigens corresponding to the HLA typing of their previous donor (UA-PD) as a proxy for donor-specific antibodies. Linear regression was applied to estimate the effects of HLA mismatches on UA-PD and the effects of UA-PD on calculated panel reactive antibody (cPRA) values for 4867 kidney recipients from 2010 to 2021.

RESULTS

Each additional HLA-DQ mismatch increased the probability of UA-PD by 25.2% among deceased donor transplant recipients and by 28.9% among living donor transplant recipients, significantly more than all other HLA loci (P<0.05). HLA-DQ UA-PD increased cPRA by 29.0% in living donor transplant recipients and by 23.5% in deceased donor transplant recipients, significantly more than all loci except for HLA-A in deceased donor transplant recipients (23.1%). African American deceased donor transplant recipients were significantly more likely than Hispanic and White recipients to develop HLA-DQ UA-PD; among living donor transplant recipients, African American or Hispanic recipients were significantly more likely to do so compared with White recipients. Models evaluating interactions between HLA-DR/DQ mismatches revealed largely independent effects of HLA-DQ mismatches on HLA-DQ UA-PD.

CONCLUSIONS

HLA-DQ mismatches had the strongest associations with UA-PD, an effect that was greatest in African American and Hispanic recipients. cPRA increases with HLA-DQ UA-PD were equivalent or larger than any other HLA locus. This suggests a need to consider the effects of HLA-DQ in kidney allocation.

Comparative outcomes for over 100 deceased donor kidney transplants from SARS-CoV-2 positive donors: A single-center experience

Emerging data support the safety of transplantation of extra-pulmonary organs from donors with SARS-CoV-2-detection. Our center offered kidney transplantation (KT) from deceased donors (DD) with SARS-CoV-2 with and without COVID-19 as a cause of death (CoV + COD and CoV+) to consenting candidates. No pre-emptive antiviral therapies were given. We retrospectively compared outcomes to contemporaneous DDKTs with negative SARS-CoV-2 testing (CoVneg). From February 1, 2021 to January 31, 2022, there were 220 adult KTs, including 115 (52%) from 35 CoV+ and 33 CoV + COD donors. Compared to CoVneg and CoV+, CoV + COD were more often DCD (100% vs. 40% and 46%, p < .01) with longer cold ischemia times (25.2 h vs. 22.9 h and 22.2 h, p = .02). At median follow-up of 5.7 months, recipients of CoV+, CoV + COD and CoVneg kidneys had similar rates of delayed graft function (10.3%, 21.8% and 21.9%, p = .16), rejection (5.1%, 0% and 8.5%, p = .07), graft failure (1.7%, 0% and 0%, p = .35), mortality (0.9%, 0% and 3.7%; p = .29), and COVID-19 diagnoses (13.6%, 7.1%, and 15.2%, p = .33). Though follow-up was shorter, CoV + COD was associated with lower but acceptable eGFR on multivariable analysis. KT from DDs at various stages of SARS-CoV-2 infection appears safe and successful. Extended follow-up is required to assess the impact of CoV + COD donors on longer term graft function.

Aspirin for Primary and Secondary Prevention of Mortality, Cardiovascular Disease, and Kidney Failure in the Chronic Renal Insufficiency Cohort (CRIC) Study

Rationale and Objective

Chronic kidney disease is a risk enhancing factor for cardiovascular disease (CVD) and mortality, and the role of aspirin use is unclear in this population. We investigated the risk and benefits of aspirin use in primary and secondary prevention of CVD in the Chronic Renal Insufficiency Cohort Study.

Study Design

Prospective observational cohort.

Setting & Participants

3,664 Chronic Renal Insufficiency Cohort participants.

Exposure

Aspirin use in patients with and without preexisting CVD.

Outcomes

Mortality, composite and individual CVD events (myocardial infarction, stroke, and peripheral arterial disease), kidney failure (dialysis and transplant), and major bleeding.

Analytical Approach

Intention-to-treat analysis and multivariable Cox proportional hazards model to examine associations of time varying aspirin use.

Results

The primary prevention group was composed of 2,578 (70.3%) individuals. Mean age was 57 ± 11 years, 46% women, 42% Black, and 47% had diabetes. The mean estimated glomerular filtration rate was 45 mL/min/1.73 m2. Median follow-up was 11.5 (IQR, 7.4-13) years. Aspirin was not associated with all-cause mortality in those without preexisting cardiovascular disease (CVD) (HR, 0.84; 95% CI, 0.7-1.01; P = 0.06) or those with CVD (HR, 0.88; 95% CI, 0.77-1.02, P = 0.08). Aspirin was not associated with a reduction of the CVD composite in primary prevention (HR, 0.97; 95% CI, 0.77-1.23; P = 0.79) and in secondary prevention because the original study design was not meant to study the effects of aspirin.

Limitations

This is not a randomized controlled trial, and therefore, causality cannot be determined.

Conclusions

Aspirin use in chronic kidney disease patients was not associated with reduction in primary or secondary CVD events, progression to kidney failure, or major bleeding.

Utilization and outcomes of deceased donor SARS-CoV-2-positive organs for solid organ transplantation in the United States

Coronavirus disease-19 has had a marked impact on the transplant population and processes of care for transplant centers and organ allocation. Several single-center studies have reported successful utilization of deceased donors with positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests. Our aims were to characterize testing, organ utilization, and transplant outcomes with donor SARS-CoV-2 status in the United States. We used Scientific Registry of Transplant Recipients data from March 12, 2020 to August 31, 2021 including a custom file with SARS-CoV-2 testing data. There were 35 347 donor specimen SARS-CoV-2 tests, 77.5% upper respiratory samples, 94.6% polymerase chain reaction tests, and 1.2% SARS-CoV-2-positive tests. Donor age, gender, history of hypertension, and diabetes were similar by SARS-CoV-2 status, while positive SARS-CoV-2 donors were more likely African-American, Hispanic, and donors after cardiac death (p-values <.01). Recipient demographic characteristics were similar by donor SARS CoV-2 status. Adjusted donor kidney discard (odds ratio = 2.08, 95% confidence interval [CI] 1.66-2.61) was higher for SARS-CoV-2-positive donors while donor liver (odds ratio = 0.44, 95% CI 0.33-0.60) and heart recovery (odds ratio = 0.44, 95% CI 0.31-0.63) were significantly reduced. Overall post-transplant graft survival for kidney, liver, and heart recipients was comparable by donor SARS-CoV-2 status. Cumulatively, there has been significantly lower utilization of SARS-CoV-2 donors with no evidence of reduced recipient graft survival with variations in practice over time.

Survey of Salary and Job Satisfaction of Transplant Nephrologists in the United States

BACKGROUND AND OBJECTIVES

There are no standardized benchmarks to measure productivity and compensation of transplant nephrologists in the United States, and consequently, criteria set for general nephrologists are often used.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A web-based survey was sent to 809 nephrologists who were members of the American Society of Transplantation to gather data on measures of productivity, compensation, and job satisfaction. Factors associated with higher total compensation and job satisfaction were examined.

RESULTS

Of 365 respondents, 260 were actively practicing in the United States and provided data on compensation. Clinical productivity was assessed variably, and although 194 (76%) had their work relative value units (wRVUs) reported to them, only 107 (44%) had an established RVU target. Two hundred thirty-four respondents (90%) had fixed base compensation, and 172 (66%) received a bonus on the basis of clinical workload (68%), academic productivity (31%), service (32%), and/or teaching responsibility (31%). Only 127 respondents (49%) filled out time studies, and 92 (35%) received some compensation for nonbillable transplant activity. Mean total compensation (base salary and bonus) was $274,460±$91,509. The unadjusted mean total compensation was higher with older age and was higher for men; Hispanic and White respondents; adult care transplant nephrologists; residents of the western United States; US medical school graduates; nonuniversity hospital employees; and those with an administrative title, higher academic rank, and a higher number of years in practice. Two hundred and nine respondents (80%) thought their compensation was unfair, and 180 (70%) lacked a clear understanding of how they were compensated. One hundred forty-five respondents (55%) reported being satisfied or highly satisfied with their job. Job satisfaction was greater among those with higher amounts of compensation and US medical school graduates.

CONCLUSIONS

We report significant heterogeneity in the assessment of productivity and compensation for transplant nephrologists and the association of compensation with job satisfaction.

Survival Benefit of Living-Donor Liver Transplant

Importance

Despite the acceptance of living-donor liver transplant (LDLT) as a lifesaving procedure for end-stage liver disease, it remains underused in the United States. Quantification of lifetime survival benefit and the Model for End-stage Liver Disease incorporating sodium levels (MELD-Na) score range at which benefit outweighs risk in LDLT is necessary to demonstrate its safety and effectiveness.

Objective

To assess the survival benefit, life-years saved, and the MELD-Na score at which that survival benefit was obtained for individuals who received an LDLT compared with that for individuals who remained on the wait list.

Design, Setting, and Participants

This case-control study was a retrospective, secondary analysis of the Scientific Registry of Transplant Recipients database of 119 275 US liver transplant candidates and recipients from January 1, 2012, to September 2, 2021. Liver transplant candidates aged 18 years or older who were assigned to the wait list (N = 116 455) or received LDLT (N = 2820) were included. Patients listed for retransplant or multiorgan transplant and those with prior kidney or liver transplants were excluded.

Exposures

Living-donor liver transplant vs remaining on the wait list.

Main Outcomes and Measures

The primary outcome of this study was life-years saved from receiving an LDLT. Secondary outcomes included 1-year relative mortality and risk, time to equal risk, time to equal survival, and the MELD-Na score at which that survival benefit was obtained for individuals who received an LDLT compared with that for individuals who remained on the wait list. MELD-Na score ranges from 6 to 40 and is well correlated with short-term survival. Higher MELD-Na scores (>20) are associated with an increased risk of death.

Results

The mean (SD) age of the 119 275 study participants was 55.1 (11.2) years, 63% were male, 0.9% were American Indian or Alaska Native, 4.3% were Asian, 8.2% were Black or African American, 15.8% were Hispanic or Latino, 0.2% were Native Hawaiian or Other Pacific Islander, and 70.2% were White. Mortality risk and survival models confirmed a significant survival benefit for patients receiving an LDLT who had a MELD-Na score of 11 or higher (adjusted hazard ratio, 0.64 [95% CI, 0.47-0.88]; P = .006). Living-donor liver transplant recipients gained an additional 13 to 17 life-years compared with patients who never received an LDLT.

Conclusions and Relevance

An LDLT is associated with a substantial survival benefit to patients with end-stage liver disease even at MELD-Na scores as low as 11. The findings of this study suggest that the life-years gained are comparable to or greater than those conferred by any other lifesaving procedure or by a deceased-donor liver transplant. This study's findings challenge current perceptions regarding when LDLT survival benefit occurs.

Cotesting for Human Immunodeficiency Virus and Sexually Transmitted Infections in the Emergency Department

BACKGROUND

The Centers for Disease Control and Prevention (CDC) and US Preventive Services Task Force (USPSTF) guidelines recommend screening for human immunodeficiency virus (HIV) in patients aged 15 to 65 years, as well as those at increased risk. Patients screened in the emergency department (ED) for gonorrhea (GC) and/or chlamydia represent an increased-risk population. Our aim was to assess compliance with CDC and USPSTF guidelines for HIV testing in a national sample of EDs.

METHODS

We examined data from the 2010 to 2018 Nationwide Emergency Department Sample, which can be used to create national estimates of ED care to query tests for GC, chlamydia, HIV, and syphilis testing. Weighted proportions and 95% confidence intervals (CIs) were reported, and Rao-Scott χ 2 tests were used.

RESULTS

We identified 13,443,831 (weighted n = 3,094,214) high-risk encounters in which GC/chlamydia testing was performed. HIV screening was performed in 3.9% (95% CI, 3.4-4.3) of such visits, and syphilis testing was performed in 2.9% (95% CI, 2.7-3.2). Only 1.5% of patients with increased risk encounters received both HIV and syphilis cotesting.

CONCLUSIONS

Despite CDC and USPSTF recommendations for HIV and syphilis screening in patients undergoing STI evaluation, only a small proportion of patients are being tested. Further studies exploring the barriers to HIV screening in patients undergoing STI assessment in the ED may help inform future projects aimed at increasing guidance compliance.

Preoperative assessment using the five-factor modified frailty index: A call for standardized preoperative assessment and prehabilitation services in gynecologic oncology

OBJECTIVE

To evaluate if the 5-factor modified frailty index (mFI) is associated with postoperative complications, readmissions or non-home discharge in gynecologic cancer patients undergoing surgery.

METHODS

Patients with a diagnosis of gynecologic cancer (cervical, uterine, or ovarian cancer) who underwent surgery between 2014 and 2018 were identified through the National Surgical Quality Improvement Program (NSQIP) database. The 5-factor mFI was applied and patients classified into 6 categories (mFI groups 0,1,2, 3, 4 and 5). The incidence of 30-day complications, readmissions and non-home discharge was evaluated. Multivariable logistic regression models were used to determine the association between mFI category and readmissions/ complications. Adjusted probabilities of events were calculated based on patient characteristics.

RESULTS

At total of 31,181 gynecologic cancer cases were included in the analysis: N = 2968 (9.4%) cervical, N = 20,862 (66.4%) uterine, and N = 7351 (23.4%) ovarian cancers. Of all patients, 46.1% were in category 0, 36.5% category 1, and 1% category 3-5. Factors associated with increased mFI included older age, African American race, laparoscopic surgery and obesity. A significant dose-response relationship between higher mFI and readmission and 30-day complications was noted on adjusted multivariable analysis (adjusted OR 2.37 (1.65-3.45) and 2.10 (1.59-2.75) for readmissions and complications, respectively, in mFI category 3-5). These associations were consistent within each cancer type.

CONCLUSIONS

The 5-factor mFI universally predicts postoperative readmissions, 30-day complications and non-home discharge in patients with gynecologic cancer. Incorporation of mFI into routine preoperative assessment can identify patients for non-surgical treatments, prehabiliatation and short term home assessments.

A tool for decision-making in kidney transplant candidates with poor prognosis to receive deceased donor transplantation in the United States

The primary outcomes for kidney transplant candidates are receipt of deceased or living donor transplant, death or removal from the waiting list. Here, we conducted a retrospective analysis of national Scientific Registry of Transplant Recipients data to evaluate outcomes for 208,717 adult kidney transplant candidates following the 2014 Kidney Allocation System in the United States. Competing risks models were utilized to evaluate Time to Equivalent Risk (TiTER) of deceased donor transplantation (DDTX) and death versus waitlist removal. We also evaluated TiTER based on kidney donor profile index (KDPI) and donor age. For all groups, the cumulative incidence of DDTX was initially higher from time of listing than death or waitlist removal. However, following accrued time on the waiting list, the cumulative incidence of death or waitlist removal exceeded DDTX for certain patient groups, particularly older, diabetic, blood type B and O and shorter pre-listing dialysis time. TiTER for all candidates aged 65-69 averaged 41 months and for 70 and older patients 28 months. Overall, 39.6% of candidates were in risk groups with TiTER under 72 months and 18.5% in groups with TiTER under 24 months. Particularly for older candidates, TiTER for kidneys was substantially shorter for younger donors or lower KDPI. Thus, our findings reveal that a large proportion of waitlisted patients in the United States have poor prognoses to ever undergo DDTX and our data may improve shared decision-making for candidates at time of waitlist placement. Hence, for specific patient groups, TiTER may be a useful tool to disseminate and quantify benefits of accepting relatively high risk donor organs.

Validation of myasthenia gravis diagnosis in the older Medicare population

INTRODUCTION/AIMS

Administrative health data has been increasingly used to study the epidemiology of myasthenia gravis (MG) but a case ascertainment algorithm is lacking. We aimed to develop a valid algorithm for identifying MG patients in the older population with Medicare coverage.

METHODS

Local older patients (age ≥65) who received healthcare at the Cleveland Clinic and possessed Medicare coverage in 2014 and 2015 were selected. Potential MG patients were identified by using a combination of ICD9 or ICD10 codes for MG and MG-related text-word search. Diagnosis was categorized as "definite MG", "possible MG" or "non-MG" after review of clinical summaries by 5 neuromuscular specialists. Performances of various algorithms were tested by use of the definite MG cohort as a reference standard, and calculation of sensitivity, specificity, and predictive values.

RESULTS

A total of 118 988 local older patients with Medicare coverage were identified. Usage of MG ICD codes and text-word search resulted in 125 patients with definite and 67 with possible MG. A total of 45 algorithms involving ICD usage, medication prescription, and specialty visit were tested. The best performing algorithm was identified as 2 office visits using MG ICD codes separated by at least 4 weeks or 1 hospital discharge and 1 office visit each using MG ICD codes separated by at least 4 weeks within the two-year period, resulting in a sensitivity and positive predictive value of 80% for identifying definite MG patients.

DISCUSSION

Algorithms using ICD codes can reliably identify patients with MG with a high degree of accuracy.

The role of bypass filters in deceased donor kidney allocation in the United States

Kidney transplant centers set organ offer filters enabling all candidates at their center to be bypassed during allocation of deceased donor kidneys from the UNOS Organ Center. These filters aim to increase allocation efficiency by preemptively screening out offers unlikely to be accepted. National data were used to compare filter settings of 175 centers in 2007 and in 2019. We examined characteristics of centers whose settings became increasingly restrictive over time, and associations between filter settings and organ offer acceptance. Overall, centers became more open to receiving offers over time, from a median 62% of filters open to receiving national offers in 2007 to 73% in 2019. Intravenous drug use filter settings changed most, from 63 to 153 willing centers. Centers with more open filter settings had higher transplant volume and offer acceptance ratios across all risk categories despite preemptively screening out fewer offers compared to centers with less open settings, but similar transplant rates. There was significant geographic heterogeneity in the distribution of centers with more open filter settings. Current center bypass filters may impact patients' access to transplantation without achieving their full potential for improving allocation efficiency.