James K. Koford

Role of Socioeconomic Status in Kidney Transplant Outcome

There is controversy regarding the influence of genetic versus environmental factors on kidney transplant outcome in minority groups. The goal of this project was to evaluate the role of certain socioeconomic factors in allograft and recipient survival. Graft and recipient survival data from the United States Renal Data System were analyzed using Cox modeling with primary variables of interest, including recipient education level, citizenship, and primary source of pay for medical service. College (hazard ratio [HR] 0.93, P < 0.005) and postcollege education (HR 0.85, P < 0.005) improved graft outcome in the whole group and in patients of white race. Similar trends were observed for recipient survival (HR 0.9, P < 0.005 for college; HR 0.88, P = 0.09 for postcollege education) in the whole population and in white patients. Resident aliens had a significantly better graft outcome in the entire patient population (HR 0.81, P < 0.001) and in white patients in subgroup analysis (HR 0.823, P < 0.001) compared with US citizens. A similar effect was observed for recipient survival. Using Medicare as a reference group, there is a statistically significant benefit to graft survival from having private insurance in the whole group (HR 0.87, P < 0.001) and in the black (HR 0.8, P < 0.001) and the white (HR 0.89, P < 0.001) subgroups; a similar effect of private insurance is observed on recipient survival in the entire group of patients and across racial groups. Recipients with higher education level, resident aliens, and patients with private insurance have an advantage in the graft and recipient outcomes independent of racial differences.

Factors affecting kidney-transplant outcome in recipients with lupus nephritis.

Abstract:  Background:  Factors associated with outcome in renal transplant recipients with lupus nephritis have not been studied.

The impact of employment status on recipient and renal allograft survival

Abstract: Background:  With the improved median survival of kidney transplant recipients, there has been an increased focus on quality of life after transplantation. Employment is a widely recognized component of quality of life. To date, no study has demonstrated a link between post‐transplant employment status and recipient and allograft survival after transplant.

Effect of education on racial disparities in access to kidney transplantation

Goldfarb‐Rumyantzev AS, Sandhu GS, Baird B, Barenbaum A, Yoon JH, Dimitri N, Koford JK, Shihab F. Effect of education on racial disparities in access to kidney transplantation. 
Clin Transplant 2012: 26: 74–81. 
© 2010 John Wiley & Sons A/S.

Effect of donors' intravenous drug use, cigarette smoking, and alcohol dependence on kidney transplant outcome.

Background. The shortage of organ donors for kidney transplants has made the expansion of the kidney donor pool a clinically significant issue. Previous studies suggest that kidneys from donors with a history of intravenous (IV) drug, cigarette, and/or alcohol use are considered to be a risky choice. However, these kidneys could potentially be used and expand the kidney supply pool if no evidence shows their association with adverse transplant outcomes. Methods. This study analyzed the United Network for Organ Sharing dataset from 1994 to 1999 using Kaplan-Meier survival analysis and Cox modeling. The effects on transplant outcome (graft and recipient survival) were examined with respect to the donors’ IV drug use, cigarette smoking, and alcohol dependency. Covariates including the recipient variables, the donor variables, and the transplant procedure variables were included in the Cox models. Results. The results show that the donors’ history of cigarette smoking is a statistically significant risk factor for both graft survival (hazard ratio = 1.05, P < 0.05) and recipient survival (1.06, P<0.05), whereas neither IV drug use nor alcohol dependency had significant adverse impact on graft or recipient survival. Conclusions. Assuming that adequate testing for potential infections is performed, there is no evidence to support avoiding the kidneys from donors with IV drug use or alcohol dependency in transplantation. Utilizing these kidneys would clearly expand the potential pool of donor organs.

Role of pre‐transplant marital status in renal transplant outcome

Abstract:  Background:  End‐stage renal disease is associated with illness‐induced disruptions that challenge patients and their families to accommodate and adapt. However, the impact of patients’ marital status on kidney transplant outcome has never been studied. This project, based on data from United States Renal Data System (USRDS), helps to answer how marriage affects renal transplant outcome.

Predicting Kidney Transplant Survival Using Tree-based Modeling

Predicting the outcome of kidney transplantation is clinically important and computationally challenging. The goal of this project was to develop the models predicting probability of kidney allograft survival at 1, 3, 5, 7, and 10 years. Kidney transplant data from the United States Renal Data System (January 1, 1990, to December 31, 1999, with the follow-up through December 31, 2000) were used (n = 92,844). Independent variables included recipient demographic and anthropometric data, end-stage renal disease course, comorbidity information, donor data, and transplant procedure variables. Tree-based models predicting the probability of the allograft survival were generated using roughly two-thirds of the data (training set), with the remaining one-third left aside to be used for models validation (testing set). The prediction of the probability of graft survival in the independent testing dataset achieved a good correlation with the observed survival (r = 0.94, r = 0.98, r = 0.99, r = 0.93, and r = 0.98) and relatively high areas under the receiving operator characteristic curve (0.63, 0.64, 0.71, 0.82, and 0.90) for 1-, 3-, 5-, 7-, and 10-year survival prediction, respectively. The models predicting the probability of 1-, 3-, 5-, 7-, and 10-year allograft survival have been validated on the independent dataset and demonstrated performance that may suggest implementation in clinical decision support system.

The association between length of post-kidney transplant hospitalization and long-term graft and recipient survival

Abstract: Background: There has been a general trend towards shortened length of post‐kidney transplant hospitalization (LOH). The decision regarding patientss discharge from the hospital theoretically may be based on several factors, including, but not limited to, patient well being, insurance status, family situation and other, mostly socio‐economic factors, as opposed to hard medical evidence. However, the appropriate LOH in kidney transplant recipients is not well studied regarding long‐term outcomes.

Education is associated with reduction in racial disparities in kidney transplant outcome.

In this study, we hypothesized that higher level of education might be associated with reduced racial disparities in renal transplantation outcomes.

The role of the economic environment in kidney transplant outcomes

Abstract:  The relationship between global economic indicators and kidney allograft and patient survival is unknown. To investigate possible relationships between the two, we analyzed kidney transplant recipients receiving transplants between January of 1995 and December of 2002 (n = 105 181) in the USA using Cox regression models. We found that: The Dow Jones Industrial Average had a negative association with outcome at one year post‐transplant (HR 1.03 and 1.06, p < 0.001 for graft and recipient survival, respectively) but changed to a protective effect in the late period (HR 0.77, p < 0.001, and HR 0.83, p < 0.001 for graft and recipient survival, respectively, five yr after transplantation). Unemployment rate had a protective effect at the time of transplantation (HR 0.97, p < 0.005) and at one year after transplantation (HR 0.95, p < 0.005) but changed to the opposite in the late period at the fifth post‐transplant year (HR 1.35, p < 0.001, and HR 1.20, p < 0.001, for graft and recipient survival respectively). The Consumer Price Index measured at different post‐transplant time points seems to have had a protective effect on the graft (HR 0.77, p < 0.001 at five yr) and recipient (HR 0.83, p < 0.001 at five yr) survival. Beyond three yr after transplantation, when some of the recipients lose Medicare benefits, economic downturns might have a negative association with the kidney graft and recipient survival.