Paolo R. Salvalaggio

Racial Variation in Medical Outcomes among Living Kidney Donors

BACKGROUND Data regarding health outcomes among living kidney donors are lacking, especially among nonwhite persons. METHODS We linked identifiers from the Organ Procurement and Transplantation Network (OPTN) with administrative data of a private U.S. health insurer and performed a retrospective study of 4650 persons who had been living kidney donors from October 1987 through July 2007 and who had post-donation nephrectomy benefits with this insurer at some point from 2000 through 2007. We ascertained post-nephrectomy medical diagnoses and conditions requiring medical treatment from billing claims. Cox regression analyses with left and right censoring to account for observed periods of insurance benefits were used to estimate absolute prevalence and prevalence ratios for diagnoses after nephrectomy. We then compared prevalence patterns with those in the 2005-2006 National Health and Nutrition Examination Survey (NHANES) for the general population. RESULTS Among the donors, 76.3% were white, 13.1% black, 8.2% Hispanic, and 2.4% another race or ethnic group. The median time from donation to the end of insurance benefits was 7.7 years. After kidney donation, black donors, as compared with white donors, had an increased risk of hypertension (adjusted hazard ratio, 1.52; 95% confidence interval [CI], 1.23 to 1.88), diabetes mellitus requiring drug therapy (adjusted hazard ratio, 2.31; 95% CI, 1.33 to 3.98), and chronic kidney disease (adjusted hazard ratio, 2.32; 95% CI, 1.48 to 3.62); findings were similar for Hispanic donors. The absolute prevalence of diabetes among all donors did not exceed that in the general population, but the prevalence of hypertension exceeded NHANES estimates in some subgroups. End-stage renal disease was identified in less than 1% of donors but was more common among black donors than among white donors. CONCLUSIONS As in the general U.S. population, racial disparities in medical conditions occur among living kidney donors. Increased attention to health outcomes among demographically diverse kidney donors is needed. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.)

Transplant Outcomes and Economic Costs Associated with Patient Noncompliance to Immunosuppression

We describe factors associated with immunosuppression compliance after kidney transplantation and examine relationships between compliance with allograft outcomes and costs. Medicare claims for immunosuppression in 15 525 renal transplant recipients with at least 1 year of graft function were used to calculate compliance as medication possession ratio. Compliance was categorized by quartiles as poor, fair, good and excellent. We modeled adjusted associations of clinical factors with the likelihood of persistent compliance by multiple logistic regressions (aOR), and estimated associations of compliance with subsequent graft and patient survival with Cox proportional hazards (aHR). Adolescent recipients aged 19–24 years were more likely to be persistently noncompliant compared to patients aged 24–44 years (aOR 1.49 [1.06–2.10]). Poor (aHR 1.80 [1.52–2.13]) and fair (aHR 1.63[1.37–1.93]) compliant recipients were associated with increased risks of allograft loss compared to the excellent compliant recipients. Persistent low compliance was associated with a

MELD Exceptions and Rates of Waiting List Outcomes

12 840 increase in individual 3‐year medical costs. Immunosuppression medication possession ratios indicative of less than the highest quartile of compliance predicted increased risk of graft loss and elevated costs. These findings suggest that interventions to improve medication compliance among kidney transplant recipients should emphasize the benefits of maximal compliance, rather than discourage low compliance.

The Interplay of Socioeconomic Status, Distance to Center, and Interdonor Service Area Travel on Kidney Transplant Access and Outcomes

Model for End‐stage Liver Disease (MELD)‐based allocation of deceased donor livers allows exceptions for patients whose score may not reflect their true mortality risk. We hypothesized that organ procurement organizations (OPOs) may differ in exception practices, use of exceptions may be increasing over time, and exception patients may be advantaged relative to other patients. We analyzed longitudinal MELD score, exception and outcome in 88 981 adult liver candidates as reported to the United Network for Organ Sharing from 2002 to 2010. Proportion of patients receiving an HCC exception was 0–21.4% at the OPO‐level and 11.9–18.8% at the region level; proportion receiving an exception for other conditions was 0.0%–13.1% (OPO‐level) and 3.7–9.5 (region‐level). Hepatocellular carcinoma (HCC) exceptions rose over time (10.5% in 2002 vs. 15.5% in 2008, HR = 1.09 per year, p<0.001) as did other exceptions (7.0% in 2002 vs. 13.5% in 2008, HR = 1.11, p<0.001). In the most recent era of HCC point assignment (since April 2005), both HCC and other exceptions were associated with decreased risk of waitlist mortality compared to nonexception patients with equivalent listing priority (multinomial logistic regression odds ratio [OR] = 0.47 for HCC, OR = 0.43 for other, p<0.001) and increased odds of transplant (OR = 1.65 for HCC, OR = 1.33 for other, p<0.001). Policy advantages patients with MELD exceptions; differing rates of exceptions by OPO may create, or reflect, geographic inequity.

Bariatric surgery among kidney transplant candidates and recipients: Analysis of the United States Renal Data System and literature review

BACKGROUND AND OBJECTIVES Variation in kidney transplant access across the United States may motivate relocation of patients with ability to travel to better-supplied areas. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We examined national transplant registry and U.S. Census data for kidney transplant candidates listed in 1999 to 2009 with a reported residential zip code (n = 203,267). Coxs regression was used to assess associations of socioeconomic status (SES), distance from residence to transplant center, and relocation to a different donation service area (DSA) with transplant access and outcomes. RESULTS Patients in the highest SES quartile had increased access to transplant compared with those with lowest SES, driven strongly by 76% higher likelihood of living donor transplantation (adjusted hazard ratio [aHR] 1.76, 95% confidence interval [CI] 1.70 to 1.83). Waitlist death was reduced in high compared with low SES candidates (aHR 0.86, 95% CI 0.84 to 0.89). High SES patients also experienced lower mortality after living and deceased donor transplant. Patients living farther from the transplant center had reduced access to deceased donor transplant and increased risk of post-transplant death. Inter-DSA travel was associated with a dramatic increase in deceased donor transplant access (HR 1.94, 95% CI 1.88 to 2.00) and was predicted by high SES, white race, and longer deceased-donor allograft waiting time in initial DSA. CONCLUSIONS Ongoing disparities exist in kidney transplantation access and outcomes on the basis of geography and SES despite near-universal insurance coverage under Medicare. Inter-DSA travel improves access and is more common among high SES candidates.

Addressing Geographic Disparities in Liver Transplantation Through Redistricting

Background. Limited data exist on the safety and efficacy of bariatric surgery (BS) in patients with kidney failure. Methods. We examined Medicare billing claims within USRDS registry data (1991–2004) to identify BS cases among renal allograft candidates and recipients. Results. Of 188 BS cases, 72 were performed pre-listing, 29 on the waitlist, and 87 post-transplant. Roux-en-Y gastric bypass was the most common procedure. Thirty-day mortality after BS performed on the waitlist and post-transplant was 3.5%, and one transplant recipient lost their graft within 30 days after BS. BMI data were available for a subset and suggested median excess body weight loss of 31%–61%. Comparison to published clinical trials of BS in populations without kidney disease indicates comparable weight loss but higher post-BS mortality in the USRDS sample. Conclusions. Given the substantial contributions of obesity to excess morbidity and mortality, BS warrants prospective study as a strategy for improving outcomes before and after kidney transplantation.

The interaction among donor characteristics, severity of liver disease, and the cost of liver transplantation

Severe geographic disparities exist in liver transplantation; for patients with comparable disease severity, 90‐day transplant rates range from 18% to 86% and death rates range from 14% to 82% across donation service areas (DSAs). Broader sharing has been proposed to resolve geographic inequity; however, we hypothesized that the efficacy of broader sharing depends on the geographic partitions used. To determine the potential impact of redistricting on geographic disparity in disease severity at transplantation, we combined existing DSAs into novel regions using mathematical redistricting optimization. Optimized maps and current maps were evaluated using the Liver Simulated Allocation Model. Primary analysis was based on 6700 deceased donors, 28 063 liver transplant candidates, and 242 727 Model of End‐Stage Liver Disease (MELD) changes in 2010. Fully regional sharing within the current regional map would paradoxically worsen geographic disparity (variance in MELD at transplantation increases from 11.2 to 13.5, p = 0.021), although it would decrease waitlist deaths (from 1368 to 1329, p = 0.002). In contrast, regional sharing within an optimized map would significantly reduce geographic disparity (to 7.0, p = 0.002) while achieving a larger decrease in waitlist deaths (to 1307, p = 0.002). Redistricting optimization, but not broader sharing alone, would reduce geographic disparity in allocation of livers for transplant across the United States.

Cutting Edge: Transplantation Tolerance through Enhanced CTLA-4 Expression

Accurate assessment of the impact of donor quality on liver transplant (LT) costs has been limited by the lack of a large, multicenter study of detailed clinical and economic data. A novel, retrospective database linking information from the University HealthSystem Consortium and the Organ Procurement and Transplantation Network registry was analyzed using multivariate regression to determine the relationship between donor quality (assessed through the Donor Risk Index [DRI]), recipient illness severity, and total inpatient costs (transplant and all readmissions) for 1 year following LT. Cost data were available for 9059 LT recipients. Increasing MELD score, higher DRI, simultaneous liver–kidney transplant, female sex, and prior liver transplant were associated with increasing cost of LT (P < 0.05). MELD and DRI interact to synergistically increase the cost of LT (P < 0.05). Donors in the highest DRI quartile added close to

Liver transplantation cost in the model for end‐stage liver disease era: Looking beyond the transplant admission

12,000 to the cost of transplantation and nearly

Outcomes of Pancreas Transplantation in the United States Using Cardiac-Death Donors

22,000 to posttransplant costs in comparison to the lowest risk donors. Among the individual components of the DRI, donation after cardiac death (increased costs by