Tempie Shearon - Academia.edu (original) (raw)

Papers by Tempie Shearon

Journal of the American Society of Nephrology, 2001

Hyperphosphatemia is highly prevalent among patients with end-stage renal disease (ESRD) and is a... more Hyperphosphatemia is highly prevalent among patients with end-stage renal disease (ESRD) and is associated with increased mortality risk in hemodialysis (HD) patients. The mechanism through which this mortality risk is mediated is unclear. Data from two national random samples of HD patients (n ϭ 12,833) was used to test the hypothesis that elevated serum PO 4 contributes mainly to cardiac causes of death. During a 2-yr follow-up, the cause-specific relative risk (RR) of death for patients was analyzed separately for several categories of cause of death, including coronary artery disease (CAD), sudden death, and other cardiac causes, cerebrovascular and infection. Cox regression models were fit for each of the eight cause of death categories, adjusting for patient demographics and non-cardiovascular comorbid conditions. Time at risk for each cause-specific model was censored at death that resulted from any of the other causes. Higher mor

Clinical Kidney Journal, 2015

Background: Longer nephrology care before end-stage renal disease (ESRD) has been linked with bet... more Background: Longer nephrology care before end-stage renal disease (ESRD) has been linked with better outcomes. Methods: We investigated whether longer pre-end-stage renal disease (ESRD) nephrology care was associated with lower mortality at both the patient and state levels among 443 761 incident ESRD patients identified in the USA between 2006 and 2010. Results: Overall, 33% of new ESRD patients had received no prior nephrology care, while 28% had received care for >12 months. At the patient level, predictors of >12 months of nephrology care included having health insurance, white race, younger age, diabetes, hypertension and US region. Longer pre-ESRD nephrology care was associated with lower first-year mortality (adjusted hazard ratio = 0.58 for >12 months versus no care; 95% confidence interval 0.57-0.59), higher albumin and hemoglobin, choice of peritoneal dialysis and native fistula and discussion of transplantation options. Living in a state with a 10% higher proportion of patients receiving >12 months of pre-ESRD care was associated with a 9.3% lower relative mortality rate, standardized for case mix (R 2 = 0.47; P < 0.001).

Liver Transplantation, 2014

Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth... more Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth and identify associated factors in a multicenter study. Three hundred and fifty donors and 353 recipients in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) receiving transplants between March 2003 and February 2010 were included. Potential predictors of 3-month liver volume included total and standard liver volumes (TLV and SLV), Model for End-Stage Liver Disease (MELD) score (in recipients), the remnant and graft size, remnant-to-donor and graft-to-recipient weight ratios (RDWR and GRWR), remnant/TLV, and graft/SLV. Among donors, 3-month absolute growth was 676 6 251 g (mean 6 SD), and percentage reconstitution was 80% 6 13%. Among recipients, GRWR was 1.3% 6 0.4% (8 < 0.8%). Graft weight was 60% 6 13% of SLV. Three-month absolute growth was 549 6 267 g, and percentage reconstitution was 93% 6 18%. Predictors of greater 3-month liver volume included larger patient size (donors and recipients), larger graft volume (recipients), and larger TLV (donors). Donors with the smallest remnant/TLV ratios had larger than expected growth but also had higher postoperative bilirubin and international normalized ratio at 7 and 30 days. In a combined donor-recipient analysis, donors had smaller 3-month liver volumes than recipients adjusted for patient size, remnant or graft volume, and TLV or SLV (P 5 0.004). Recipient graft failure in the first 90 days was predicted by poor graft function at day 7 (HR 5 4.50, P 5 0.001)

Journal of the American Society of Nephrology, 2003

ABSTRACT. It is unclear whether peritoneal dialysis (PD) compared with hemodialysis (HD) confers ... more ABSTRACT. It is unclear whether peritoneal dialysis (PD) compared with hemodialysis (HD) confers a survival advantage in end-stage renal disease (ESRD) patients with coronary artery disease (CAD). This hypothesis was tested in a national cohort of 107,922 patients starting dialysis therapy between May 1, 1995, and July 31, 1997. Data on patient characteristics were obtained from the Center for Medicare and Medicaid Services Medical Evidence Form (CMS) and linked to mortality data from the United States Renal Data System (USRDS). Patients were classified on the basis of CAD presence and followed until death or the end of 2 yr. Nonproportional Cox regression models estimated the relative risk (RR) of death for patients with and without CAD by dialysis modality using primarily the intent-to-treat but also the as-treated approach. Diabetic patients (DM) and nondiabetic patients (non-DM) were analyzed separately. Among DM, patients with CAD treated with PD had a 23% higher RR (95% CI, 1....

The Journal of Heart and Lung Transplantation, 2009

The Journal of Heart and Lung Transplantation, 2008

were 2,427 patients who underwent LTx during the study period. Of these, 530 patients were in the... more were 2,427 patients who underwent LTx during the study period. Of these, 530 patients were in the high LAS group. The mean follow-up time for the high LAS group was 142.4 days. The average age was 51.5Ϯ14.1 and 40.6% were females. The majority of patients in the high LAS group were transplanted for IPF (51.3%) and CF (14.2%), while patients with COPD (3.4%) and pulmonary arterial hypertension (0.9%) were only a small portion of the group. For the high LAS group, the 30-day, 60-day, 90-day, and 365-day survival were 93%, 86%, 82%, and 69% respectively. In the high LAS group, there was no significant effect of diagnosis on short term survival. Likewise, age, sex, BMI, FVC, creatinine, diabetes, oxygen requirement, and 6-MWT distance had no significant effect on mortality. There was a trend towards decreased survival among patients on mechanical ventilation (HR: 1.45; 95% CI: 0.83-2.55), but this did not reach statistical significance. Conclusions: The current study examined all high LAS LTx patients reported to UNOS from 2005-2007. No single risk factor had a significant influence on survival. Importantly, the LAS independently identifies a high risk cohort, regardless of diagnosis.

American Journal of Transplantation, 2009

Living donor liver transplantation (LDLT) may have better immunological outcomes compared to dece... more Living donor liver transplantation (LDLT) may have better immunological outcomes compared to deceased donor liver transplantation (DDLT). The aim of this study was to analyze the incidence of acute cellular rejection (ACR) after LDLT and DDLT. Data from the adultto-adult living donor liver transplantation (A2ALL) retrospective cohort study on 593 liver transplants done between May 1998 and March 2004 were studied (380 LDLT; 213 DDLT). Median LDLT and DDLT follow-up was 778 and 713 days, respectively. Rates of clinically treated and biopsy-proven ACR were compared. There were 174 (46%) LDLT and 80 (38%) DDLT recipients with ≥1 clinically treated episodes of ACR, whereas 103 (27%) LDLT and 58 (27%) DDLT recipients had ≥1 biopsy-proven ACR episode. A higher proportion of LDLT recipients had clinically treated ACR (p = 0.052), but this difference was largely attributable to one center. There were similar proportions of biopsy-proven rejection (p = 0.97) and graft loss due to rejection (p = 0.16). Longer cold ischemia time was associated with a higher rate of ACR in both groups despite much shorter median cold ischemia time in LDLT. These data do not show an immunological advantage for LDLT, and therefore do not support the application of unique posttransplant immunosuppression protocols for LDLT recipients.

American Journal of Transplantation, 2010

This article highlights trends and changes in lung and heart-lung transplantation in the United S... more This article highlights trends and changes in lung and heart-lung transplantation in the United States from 1998 to 2007. The most significant change over the last decade was implementation of the Lung Allocation Score (LAS) allocation system in May 2005. Subsequently, the number of active wait-listed lung candidates declined 54% from pre-LAS (2004) levels to the end of 2007; there was also a reduction in median waiting time, from 792 days in 2004 to 141 days in 2007. The number of lung transplants performed yearly increased through the decade to a peak of 1465 in 2007; the greatest single year increase occurred in 2005. Despite candidates with increasingly higher LAS scores being transplanted in the LAS era, recipient death rates have remained relatively stable since 2003 and better than in previous years. Idiopathic pulmonary fibrosis became the most common diagnosis group to receive a lung transplant in 2007 while emphysema was the most common diagnosis in previous years. The number of retransplants and transplants in those aged ≥65 performed yearly have increased significantly since 1998, up 295% and 643%, respectively. A decreasing percentage of lung transplant recipients are children (3.5% in 2007, n = 51). With LAS refinement ongoing, monitoring of future impact is warranted.

Kidney International Reports, 2022

American Journal of Transplantation, 2020

Journal of the American Society of Nephrology, 2000

Residual renal function (RRF) in end-stage renal disease is clinically important as it contribute... more Residual renal function (RRF) in end-stage renal disease is clinically important as it contributes to adequacy of dialysis, quality of life, and mortality. This study was conducted to determine the predictors of RRF loss in a national random sample of patients initiating hemodialysis and peritoneal dialysis. The study controlled for baseline variables and included major predictors. The end point was loss of RRF, defined as a urine volume Ͻ200 ml/24 h at approximately 1 yr of follow-up. The adjusted odds ratios (AOR) and P values associated with each of the demographic, clinical, laboratory, and treatment parameters were estimated using an "adjusted" univariate analysis. Significant variables (P Ͻ 0.05) were included in a multivariate logistic regression model. Predictors of RRF loss were female gender (AOR ϭ 1.45; P Ͻ 0.001), non-white race (AOR ϭ 1.57; P ϭ Ͻ0.001), prior history of diabetes (AOR ϭ 1.82; P ϭ 0.006), prior history of congestive heart failure (AOR ϭ 1.32; P ϭ 0.03), and time to follow-up (AOR ϭ 1.06 per month; P ϭ 0.03). Patients treated with peritoneal dialysis had a 65% lower risk of RRF loss than those on hemodialysis (AOR ϭ 0.35; P Ͻ 0.001). Higher serum calcium (AOR ϭ 0.81 per mg/dl; P ϭ 0.05), use of an angiotensin-converting enzyme inhibitor (AOR ϭ 0.68; P Ͻ 0.001), and use of a calcium channel blocker (AOR ϭ 0.77; P ϭ 0.01) were independently associated with decreased risk of RRF loss. The observations of demographic groups at risk and potentially modifiable factors and therapies have generated testable hypotheses regarding therapies that may preserve RRF among end-stage renal disease patients.

American Journal of Kidney Diseases, 1999

JAMA Network Open, 2021

IMPORTANCE There is a need for studies to evaluate the risk factors for COVID-19 and mortality am... more IMPORTANCE There is a need for studies to evaluate the risk factors for COVID-19 and mortality among the entire Medicare long-term dialysis population using Medicare claims data. OBJECTIVE To identify risk factors associated with COVID-19 and mortality in Medicare patients undergoing long-term dialysis. DESIGN, SETTING, AND PARTICIPANTS This retrospective, claims-based cohort study compared mortality trends of patients receiving long-term dialysis in 2020 with previous years (2013-2019) and fit Cox regression models to identify risk factors for contracting COVID-19 and postdiagnosis mortality. The cohort included the national population of Medicare patients receiving long-term dialysis in 2020, derived from clinical and administrative databases. COVID-19 was identified through Medicare claims sources. Data were analyzed on May 17, 2021. MAIN OUTCOMES AND MEASURES The 2 main outcomes were COVID-19 and all-cause mortality. Associations of claims-based risk factors with COVID-19 and mortality were investigated prediagnosis and postdiagnosis. RESULTS Among a total of 498 169 Medicare patients undergoing dialysis (median [IQR] age, 66 [56-74] years; 215 935 [43.1%] women and 283 227 [56.9%] men), 60 090 (12.1%) had COVID-19, among whom 15 612 patients (26.0%) died. COVID-19 rates were significantly higher among Black (21 787 of 165 830 patients [13.1%]) and Hispanic (13 530 of 86 871 patients [15.6%]) patients compared with non-Black patients (38 303 of 332 339 [11.5%]), as well as patients with short (ie, 1-89 days; 7738 of 55 184 patients [14.0%]) and extended (ie, Ն90 days; 10 737 of 30 196 patients [35.6%]) nursing home stays in the prior year. Adjusting for all other risk factors, residing in a nursing home 1 to 89 days in the prior year was associated with a higher hazard for COVID-19 (hazard ratio [

Clinical Journal of the American Society of Nephrology, 2021

Background and objectivesAbout 30% of patients with AKI may require ongoing dialysis in the outpa... more Background and objectivesAbout 30% of patients with AKI may require ongoing dialysis in the outpatient setting after hospital discharge. A 2017 Centers for Medicare & Medicaid Services policy change allows Medicare beneficiaries with AKI requiring dialysis to receive outpatient treatment in dialysis facilities. Outcomes for these patients have not been reported. We compare patient characteristics and mortality among patients with AKI requiring dialysis and patients without AKI requiring incident dialysis.Design, setting, participants, & measurementsWe used a retrospective cohort design with 2017 Medicare claims to follow outpatients with AKI requiring dialysis and patients without AKI requiring incident dialysis up to 365 days. Outcomes are unadjusted and adjusted mortality using Kaplan–Meier estimation for unadjusted survival probability, Poisson regression for monthly mortality, and Cox proportional hazards modeling for adjusted mortality.ResultsIn total, 10,821 of 401,973 (3%) Me...

Motivated by the national evaluation of mortality rates at kidney transplant centers in the Unite... more Motivated by the national evaluation of mortality rates at kidney transplant centers in the United States, we sought to assess transplant center long-term survival outcomes by applying a methodology developed in Bayesian non-parametrics literature. We described a Dirichlet process model and a Dirichlet process mixture model with a Half-Cauchy for the estimation of the risk-adjusted effects of the transplant centers. To improve the model performance and interpretability, we centered the Dirichlet process. We also proposed strategies to increase model's classification ability. Finally we derived statistical measures and created graphical tools to rate transplant centers and identify outlying centers with exceptionally good or poor performance. The proposed method was evaluated through simulation, and then applied to assess kidney transplant centers from a national organ failure registry.

Statistics in Medicine, 2015

Mortality rates are probably the most important indicator for the performance of kidney transplan... more Mortality rates are probably the most important indicator for the performance of kidney transplant centers. Motivated by the national evaluation of mortality rates at kidney transplant centers in the USA, we seek to categorize the transplant centers based on the mortality outcome. We describe a Dirichlet process model and a Dirichlet process mixture model with a half-cauchy prior for the estimation of the risk-adjusted effects of the transplant centers, with strategies for improving the model performance, interpretability, and classification ability. We derive statistical measures and create graphical tools to rate transplant centers and identify outlying groups of centers with exceptionally good or poor performance. The proposed method was evaluated through simulation and then applied to assess kidney transplant centers from a national organ failure registry. Copyright

American Journal of Kidney Diseases, 1998

Journal of the American Society of Nephrology : JASN, Jan 16, 2015

Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysi... more Standardized mortality ratios (SMRs) reported by Medicare compare mortality at individual dialysis facilities with the national average, and are currently adjusted for race. However, whether the adjustment for race obscures or clarifies disparities in quality of care for minority groups is unknown. Cox model-based SMRs were computed with and without adjustment for patient race for 5920 facilities in the United States during 2010. The study population included virtually all patients treated with dialysis during this period. Without race adjustment, facilities with higher proportions of black patients had better survival outcomes; facilities with the highest percentage of black patients (top 10%) had overall mortality rates approximately 7% lower than expected. After adjusting for within-facility racial differences, facilities with higher proportions of black patients had poorer survival outcomes among black and non-black patients; facilities with the highest percentage of black patie...

Health Services Research, 2014