Faculty Bibliography

The Kidney Donor Profile Index (KDPI) has been introduced as an aid to evaluating deceased donor kidney offers, but the relative benefit of high-KDPI kidney transplantation (KT) versus the clinical alternative (remaining on the waitlist until receipt of a lower KDPI kidney) remains unknown. Using time-dependent Cox regression, we evaluated the mortality risk associated with high-KDPI KT (KDPI 71-80, 81-90 or 91-100) versus a conservative, lower KDPI approach (remain on waitlist until receipt of KT with KDPI 0-70, 0-80 or 0-90) in first-time adult registrants, adjusting for candidate characteristics. High-KDPI KT was associated with increased short-term but decreased long-term mortality risk. Recipients of KDPI 71-80 KT, KDPI 81-90 KT and KDPI 91-100 KT reached a "break-even point" of cumulative survival at 7.7, 18.0 and 19.8 months post-KT, respectively, and had a survival benefit thereafter. Cumulative survival at 5 years was better in all three high-KDPI groups than the conservative approach (p < 0.01 for each comparison). Benefit of high-KDPI KT was greatest in patients age >50 years and patients at centers with median wait time ≥33 months. Recipients of high-KDPI KT can enjoy better long-term survival; a high-KDPI score does not automatically constitute a reason to reject a deceased donor kidney.

The field of organ transplantation benefits from large, comprehensive, transplant-specific national data sets available to researchers. In addition to the widely used Organ Procurement and Transplantation Network (OPTN)-based registries (the United Network for Organ Sharing and Scientific Registry of Transplant Recipients data sets) and United States Renal Data System (USRDS) data sets, there are other publicly available national data sets, not specific to transplantation, which have historically been underutilized in the field of transplantation. Of particular interest are the Nationwide Inpatient Sample and State Inpatient Databases, produced by the Agency for Healthcare Research and Quality. The USRDS database provides extensive data relevant to studies of kidney transplantation. Linkage of publicly available data sets to external data sources such as private claims or pharmacy data provides further resources for registry-based research. Although these resources can transcend some limitations of OPTN-based registry data, they come with their own limitations, which must be understood to avoid biased inference. This review discusses different registry-based data sources available in the United States, as well as the proper design and conduct of registry-based research.

BACKGROUND:Descriptions of the sequelae of ABO-incompatible (ABOi) kidney transplantation are limited to single-center reports, which may lack power to detect important effects. METHODS:We examined U.S. Renal Data System registry data to study associations of ABOi live-donor kidney transplantation with clinical complications in a national cohort. Among 14,041 Medicare-insured transplants in 2000 to 2007, 119 non-donor-A2 ABOi transplants were identified. A2-incompatible (n=35) transplants were categorized separately. Infection and hemorrhage events were identified by diagnosis codes on billing claims. Associations of ABO incompatibility with complications were assessed by multivariate Cox regression. RESULTS:Recipients of ABOi transplants experienced significantly (P<0.05) higher incidence of wound infections (12.7% vs. 7.3%), pneumonia (7.6% vs. 3.8%), and urinary tract infections (UTIs) or pyelonephritis (24.5% vs. 15.3%) in the first 90 days compared with ABO-compatible recipients. In adjusted models, ABO incompatibility was associated with twice the risk of pneumonia (adjusted hazard ratio [aHR], 2.22; 95% confidence interval [CI], 1.14-4.33) and 56% higher risk of UTIs or pyelonephritis (aHR, 1.56; 95% CI, 1.05-2.30) in the first 90 posttransplantation days, and 3.5 times the relative risk of wound infections in days 91 to 365 (aHR, 3.55; 95% CI, 1.92-6.57). ABOi recipients, 19% of whom underwent pre- or peritransplant splenectomy, experienced twice the adjusted risk of early hemorrhage (aHR, 1.96; 95% CI, 1.19-3.24). A2-incompatible transplantation was associated only with early risk of UTIs or pyelonephritis. CONCLUSION/CONCLUSIONS:ABOi transplantation offers patients with potential live donors an additional transplant option but with higher risks of infectious and hemorrhagic complications. Awareness of these complications may help improve protocols for the management of ABOi transplantation.

OBJECTIVE:To determine casemix adjusted hospital level utilization of minimally invasive surgery for four common surgical procedures (appendectomy, colectomy, total abdominal hysterectomy, and lung lobectomy) in the United States. DESIGN/METHODS:Retrospective review. SETTING/METHODS:United States. PARTICIPANTS/METHODS:Nationwide inpatient sample database, United States 2010. METHODS:For each procedure, a propensity score model was used to calculate the predicted proportion of minimally invasive operations for each hospital based on patient characteristics. For each procedure, hospitals were categorized into thirds (low, medium, and high) based on their actual to predicted proportion of utilization of minimally invasive surgery. MAIN OUTCOME MEASURES/METHODS:The primary outcome measures were the actual and predicted proportion of procedures performed with minimally invasive surgery. Secondary outcome measures included surgical complications and hospital characteristics. RESULTS:Mean hospital utilization of minimally invasive surgery was 71.0% (423/596) for appendectomy (range 40.9-93.1% (244-555)), 28.4% (154/541) for colectomy (6.7-49.8% (36/541-269/541)), 13.0% (65/499) for hysterectomy (0.0-33.6% (0/499-168/499)), and 32.0% (67/208) for lung lobectomy (3.6-65.7% (7.5/208-137/208)). Utilization of minimally invasive surgery was highly variable for each procedure type. There was noticeable discordance between actual and predicted utilization of the surgery (range of actual to predicted ratio for appendectomy 0-1.49; colectomy 0-3.88; hysterectomy 0-6.68; lung lobectomy 0-2.51). Surgical complications were less common with minimally invasive surgery compared with open surgery, respectively: overall rate for appendectomy 3.94% (1439/36,513) v 7.90% (958/12,123), P<0.001; for colectomy: 13.8% (1689/12,242) v 35.8% (8837/24,687), P<0.001; for hysterectomy: 4.69% (270/5757) v 6.64% (1988/29,940), P<0.001; and for lung lobectomy: 17.1% (367/2145) v 25.4% (971/3824), P<0.05. High utilization of minimally invasive surgery was associated with urban location (appendectomy: odds ratio 4.66, 95% confidence interval 1.17 to 18.5; colectomy: 4.59, 1.04 to 20.3; hysterectomy: 15.0, 2.98 to 75.0), large hospital size (hysterectomy: 8.70, 1.62 to 46.8), teaching hospital (hysterectomy: 5.41, 1.27 to 23.1), Midwest region (appendectomy: 7.85, 1.26 to 49.1), south region (appendectomy: 21.0, 3.79 to 117; colectomy: 10.0, 1.83 to 54.7), and west region (appendectomy: 9.33, 1.48 to 58.8). CONCLUSION/CONCLUSIONS:Hospital utilization of minimally invasive surgery for appendectomy, colectomy, total abdominal hysterectomy, and lung lobectomy varies widely in the United States, representing a disparity in the surgical care delivered nationwide.

OBJECTIVES/OBJECTIVE:To explore whether disparities in age and sex in access to kidney transplantation (KT) originate at the time of prereferral discussions about KT. DESIGN/METHODS:Cross-sectional survey. SETTING/METHODS:Outpatient dialysis centers in Maryland (n = 26). PARTICIPANTS/METHODS:Individuals who had recently initiated hemodialysis treatment (N = 416). MEASUREMENTS/METHODS:Participants reported whether medical professionals (nephrologist, primary medical doctor, dialysis staff) and social group members (significant other, family member, friend) discussed KT with them and, when applicable, rated the tone of discussions. Relative risks were estimated using modified Poisson regression. RESULTS:Participants aged 65 and older were much less likely than those who were younger to have had discussions with medical professionals (44.5% vs 74.8%, P < .001) or social group members (47.3% vs 63.1%, P = .005). Irrespective of sex and independent of race, health-related factors, and dialysis-related characteristics, older adults were more likely not to have had discussions with medical professionals (relative risk (RR) = 1.13, 95% confidence interval (CI) = 1.03-1.24, for each 5-year increase in age through 65; RR = 1.28, 95% CI = 1.14-1.42, for each 5-year increase in age beyond 65). Irrespective of age, women were more likely (RR = 1.45, 95% CI = 1.12-1.89) not to have had discussions with medical professionals. For each 5-year increase in age, men (RR = 1.04, 95% CI = 0.99-1.10) and women (RR = 1.17, 95% CI = 1.10-1.24) were more likely not to have discussions with social group members. Of those who had discussions with medical professionals or social group members, older participants described these discussions as less encouraging (all P < .01). CONCLUSION/CONCLUSIONS:Older adults and women undergoing hemodialysis are less likely than younger adults and men to have discussions about KT as a treatment option, supporting a need for better clinical guidelines and education for these individuals, their social network, and their providers.

Maximizing deceased donation rates can decrease the organ shortage. Non-transplant physicians play a critical role in facilitating conversion of potential deceased donors to actual donors, but studies suggest that physicians lack knowledge about the organ donation process. As residency and fellowship are often the last opportunities for formal medical training, we hypothesized that deficiencies in knowledge might originate in residency and fellowship. We conducted a cross-sectional survey to assess knowledge about organ donation, experience in donor conversion, and opinions of the process among residents and fellows after their intensive care unit rotations at the Johns Hopkins Hospital. Of 40 participants, 50% had previously facilitated donor conversion, 25% were familiar with the guidelines of the organ procurement organization (OPO), and 10% had received formal instruction from the OPO. The median score on the knowledge assessment was five of 10; higher knowledge score was not associated with level of medical training, prior training in or experience with donor conversion, or with favorable opinions about the OPO. We identified a pervasive deficit in knowledge among residents and fellows at an academic medical center with an active transplant program that may help explain attending-level deficits in knowledge about the organ donation process.

Despite improved overall liver transplant outcomes, biliary complications remain a significant cause of morbidity. A national data set linking transplant registry and Medicare claims data for 17,012 liver transplant recipients was used to identify all recipients with a posttransplant biliary diagnosis code within the first 6 months after transplantation. Patients were further categorized as follows: a diagnosis without a procedure, a diagnosis and an associated radiological or endoscopic procedure, or a diagnosis treated with surgery. Overall, 15.0% had a biliary diagnosis, 11.2% required a procedure, and 2.2% had a surgical revision. Factors independently associated with biliary complications included donation after cardiac death (DCD), donor age, recipient age, split grafts, and long cold ischemia times. Graft loss was significantly more common for patients with biliary diagnoses [adjusted hazard ratio (aHR) = 1.89, confidence interval (CI) = 1.63-2.19], interventions (aHR = 2.08, CI = 1.77-2.44), and surgical procedures (aHR = 1.80, CI = 1.31-2.49). Mortality after transplantation was also markedly increased for patients with biliary diagnoses (aHR = 2.18, CI = 1.97-2.40), procedures (aHR = 2.21, CI = 1.99-2.46), and surgeries (aHR = 1.77, CI = 1.41-2.23). In stratified analyses, the impact of early biliary complications was greater for DCD liver recipients, but they remained highly significant for recipients of allografts from brain-dead donors as well. Reducing biliary complications should improve posttransplant survival and reduce graft loss.