Alvin George Thomas

University of North Carolina at Chapel Hill | UNC · Department of Epidemiology

In 2013, OPTN/UNOS mandated that transplant centers collect data on living kidney donors (LKDs) at 6-months, 1-year, and 2-years post-donation, with policy-defined thresholds for the proportion of complete living donor follow-up (LDF) data submitted in a timely manner (60 days before or after the expected visit date). While mandated, it was unclear...

Innovative approaches are needed to increase engagement in HIV treatment and prevention services, particularly in HIV hot spots. Here, we detail our design, training approach, and early implementation experiences of a community-based HIV intervention called "health scouts." The intervention, utilizing a novel, theory-based approach, trained 10 comm...

BACKGROUND The geographical environments within which individuals conduct their daily activities may influence health behaviors, yet little is known about individual-level geographic mobility and specific, linked behaviors in rural, low-and-middle-income settings. OBJECTIVE Nested in a 3-month ecological momentary assessment (EMA) intervention pil...

Background: A trial found that a community health worker (CHW) strategy using "Health Scouts" improved HIV care uptake and ART coverage. To better understand outcomes and areas for improvement, we conducted an implementation science evaluation. Methods: Using the RE-AIM framework, quantitative methods included analyses of a community-wide survey...

Valid, reliable behavioral data and contextually meaningful interventions are necessary for improved health outcomes. Ecological Momentary Assessment and Intervention (EMAI), which collects data as behaviors occur to deliver real-time interventions, may be more accurate and reliable than retrospective methods. The rapid expansion of mobile technolo...

Background: Few reports have focused on newer coronavirus disease 2019 (COVID-19) therapies (remdesivir, dexamethasone, and convalescent plasma) in solid organ transplant recipients; concerns had been raised regarding possible adverse impact on allograft function or secondary infections. Methods: We studied 77 solid organ transplant inpatients w...

Increasing numbers of compatible pairs are choosing to enter paired exchange programs, but motivations, outcomes, and system‐level effects of participation is not well described. Using a linkage of the SRTR and National Kidney Registry, we compared outcomes of traditional (originally incompatible) recipients to originally compatible recipients usin...

Non-directed kidney donors can initiate living donor chains that end to patients on the waitlist. We compared 749 National Kidney Registry (NKR) waitlist chain end transplants to other transplants from the NKR and the Scientific Registry of Transplant Recipients between February 2008 and September 2020. Compared to other NKR recipients, chain end r...

Despite the institution of a new Kidney Allocation System in 2014, A2/A2B to B transplantation has not increased as expected. The current Organ Procurement and Transplantation Network policy requires subtyping on two separate occasions, and in the setting of discrepant results, defaulting to the A1 subtype. However, there is significant inherent va...

Introduction: Poor lung function and aortic stiffness often co-occur, but causal and temporal relationships are equivocal. Investigating relationships between mid-life lung function and arterial stiffness later in life may highlight modifiable targets to slow arterial aging. Objective: Assess whether lung function in mid-life is associated with cen...

Background Effective implementation strategies are needed to increase engagement in HIV services in hyperendemic settings. We conducted a pragmatic cluster-randomized trial in a high-risk, highly mobile fishing community (HIV prevalence: approximately 38%) in Rakai, Uganda, to assess the impact of a community health worker-delivered, theory-based (...

Background Live kidney donors (LKDs) account for nearly a third of kidney transplants in the United States. While donor nephrectomy poses minimal post-surgical risk, LKDs face an elevated adjusted risk of developing chronic diseases such as hypertension, diabetes, and end-stage renal disease. Routine screening presents an opportunity for the early...

BACKGROUND An extraordinary increase in mobile phone ownership has revolutionized opportunities to employ mHealth approaches in lower- and middle-income countries (LMICs). Ecological Momentary Assessment (EMA) and Intervention (EMAI) uses mobile technology to gather data and deliver timely, personalized behavior change interventions in an individua...

Background: An extraordinary increase in mobile phone ownership has revolutionized the opportunities to use mobile health approaches in lower- and middle-income countries (LMICs). Ecological momentary assessment and intervention (EMAI) uses mobile technology to gather data and deliver timely, personalized behavior change interventions in an indivi...

Background. The early effects of coronavirus disease 2019 (COVID-19) on transplantation are dramatic: >75% of kidney and liver programs are either suspended or operating under major restrictions. To resume transplantation, it is important to understand the prevalence of COVID-19 among transplant recipients, donors, and healthcare workers (HCWs) and...

The first sustained increase in live kidney donation in the US in 15 years was observed from 2017‐2019. To help sustain this surge, we studied 35,900 donors (70.3% white, 14.5% Hispanic, 9.3% black, 4.4% Asian) to understand the increase in 2017‐2019 vs. 2014‐2016 using Poisson regression. Among biologically related donors aged <35, 35‐49, and ≥50...

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time, and might compromise renal function in donors. To clarify their implications for long‐term renal function, we characterized the prevalence of renal cysts in 454 individuals w...

Prioritization of highly sensitized (HS) candidates under the Kidney Allocation System (KAS) and growth of large, multi‐center kidney‐paired donation (KPD) clearinghouses have broadened the transplant modalities available to HS candidates. To quantify temporal trends in utilization of these modalities, we used SRTR data from 2009‐2017 to study 39,9...

Background and objectives: In the United States, kidney paired donation networks have facilitated an increasing proportion of kidney transplants annually, but transplant outcome differences beyond 5 years between paired donation and other living donor kidney transplant recipients have not been well described. Design, setting, participants, & meas...

Importance Living kidney donation is associated with increased long-term risk of end-stage renal disease (ESRD). An early postdonation marker of ESRD risk could improve postdonation risk assessment and counseling for kidney donors and allow early intervention for donors at increased risk. Objective To determine the association between renal functi...

Cooperative kidney paired donation (KPD) networks account for an increasing proportion of all living donor kidney transplants in the United States. There is sparse data on the rate of primary non‐function (PNF) losses and their consequences within KPD networks. We studied National Kidney Registry (NKR) transplants (2/14/2009‐12/31/2017) and quantif...

Frailty, a measure of physiologic reserve, is associated with poor outcomes and mortality among kidney transplant (KT) candidates and recipients. There are no national estimates of frailty in this population, which may help patient counseling and resource allocation at transplant centers. We studied 4,616 KT candidates and 1,763 recipients in our m...

Background: Disability in general has been associated with poor outcomes in kidney transplant (KT) recipients. However, disability can be derived from various components, specifically visual, hearing, physical and walking impairments. Different impairments may compromise the patient through different mechanisms and might impact different aspects o...

To date, thousands of living donor kidneys have been shipped through kidney paired donation (KPD). To expand on this growing segment of living donor transplantation, we evaluated the effect of advanced age donation (“oldest kidneys”) and prolonged cold ischemia time (“coldest kidneys”) on graft function and survival using the National Kidney Regist...

Factors related to travel for transplantation were examined using data from the Scientific Registry for Transplant Recipients. Candidates who traveled abroad for a kidney transplant had higher odds of being male, Asian or Hispanic, college-educated, employed, privately insured, and a non-U.S. citizen/non-U.S. resident. Candidates with a body mass i...

Background United States transplant centers are required to report follow‐up data for living kidney donors for 2 years post‐donation. However, living kidney donor (LKD) follow‐up is often incomplete. Mobile health (mHealth) technologies could ease data collection burden but have not yet been explored in this context. Methods We conducted semi‐stru...

Introduction: Cardiovascular events, i.e. cardiac arrest and arrhythmia, are the leading cause of death among patients with end-stage renal disease (ESRD). Kidney transplantation (KT) reduces mortality and is the preferred treatment for ESRD. Generally, preemptive KT, especially with a living donor, reduces mortality over KT after dialysis initiati...

The number of live kidney donors has declined since 2005. This decline parallels the evolving knowledge of risk for biologically related, black, and younger donors. To responsibly promote donation, we sought to identify declining low‐risk donor subgroups that might serve as targets for future interventions. We analyzed a national registry of 77,427...

Background There is concern that the metrics currently used to regulate transplant centers, one‐year patient and graft survival, may have adverse consequences including decreasing higher‐risk donor organ acceptance and transplant volume. This raises questions about whether alternative measures would be more appropriate. Methods We surveyed ASTS an...

Importance In light of the growing population of older adults in the United States, older donors (aged ≥70 years) represent an expansion of the donor pool; however, their organs are underused. Liver grafts from older donors were historically associated with poor outcomes and higher discard rates, but clinical protocols, organ allocation, and the do...

In the United States, kidney donation from international (non‐citizen/non‐resident) living kidney donors (LKDs) is permitted; however, given heterogeneity of healthcare systems, concerns remain regarding international LKD practice and recipient outcomes. We studied a US cohort of 102,315 LKD transplants from 2000‐2016, including 2,088 international...

Background As transplant centers start leveraging Twitter for information dissemination and public engagement, it is important to understand current living solid organ donation‐related Twitter use. Methods We identified public Twitter profiles available in 01/2017 that referenced living organ donation and analyzed use of donation‐related Twitter h...

Background: Living kidney donors have an increased risk of end-stage renal disease, with hypertension and diabetes as the predominant causes. In this study, we sought to better understand the timeline when these diseases occur, focusing on the early postdonation period. Methods: We studied 41 260 living kidney donors in the US between 2008-2014...

Background: Previous studies have reported a wide range of prevalence of post-donation anxiety, depression, and regret in living kidney donors (LKDs). It is also unclear what risk factors are associated with these outcomes. Methods: We screened 825 LKDs for anxiety and depression using 2-item GAD-2 and PHQ-2 scales and asked about regret. Resul...

Background: Health-related quality of life (HRQOL) reflects a patient's perceived disease burden, treatment effectiveness, and health status. Given the time burden and physiologic effects of hemodialysis, patients who spend dialysis time (9-15 h/week) physically or intellectually engaged may have better HRQOL. We characterized the intradialytic ac...

Background: Cognitive impairment is common in patients with end-stage renal disease and is associated with poor outcomes on dialysis. We hypothesized that cognitive impairment might be associated with an increased risk of all-cause graft loss (ACGL) in kidney transplant (KT) recipients. Methods: Using the Modified Mini-Mental State (3MS) examina...

With new practice guidelines, it is important to understand how liver transplant (LT) centers have incorporated direct‐acting antivirals (DAAs) into the management of hepatitis C virus‐infected (HCV+) candidates and recipients. To explore how DAAs have affected LT centers’ willingness to treat HCV+ candidates and recipients and to use HCV+ donors,...

One criticism of kidney paired donation (KPD) is that easy‐to‐match candidates leave the registry quickly, thus concentrating the pool with hard‐to‐match sensitized and blood type O candidates. We studied candidate/donor pairs who registered with the National Kidney Registry, the largest US KPD clearinghouse, from 1/2012‐6/2016. There were no chang...

Background: Many kidneys are discarded every year, with 3631 kidneys discarded in 2016 alone. Identifying kidneys at high risk of discard could facilitate 'rescue' allocation to centers more likely to transplant them. The Probability of Delay or Discard (PODD) model was developed to identify marginal kidneys at risk of discard or delayed allocatio...

The impact of donor quality on post‐kidney transplant (KT) survival may vary by candidate condition. Characterizing this variation would increase access to KT without sacrificing outcomes. We developed a tool to estimate post‐KT survival for combinations of donor quality and candidate condition. We studied deceased‐donor KT recipients (N=120,818) a...

Background In the US, the Scientific Registry of Transplant Recipients (SRTR) provides publicly available quality report cards. These reports have historically rated transplant programs using a 3‐tier system. In 2016, the SRTR temporarily transitioned to a 5‐tier system, which classified more programs as under‐performing. Methods As part of a larg...

Racial disparities in living donor kidney transplantation (LDKT) persist but the most effective target to eliminate these disparities remains unknown. One potential target could be delays during completion of the live donor evaluation process. We studied racial differences in progression through the evaluation process for 247 African American (AA)...

BACKGROUND Every year, more than 5500 healthy people in the United States donate a kidney for the medical benefit of another person. The Organ Procurement and Transplantation Network (OPTN) requires transplant hospitals to monitor living kidney donors (LKDs) for 2 years postdonation. However, the majority (115/202, 57%) of transplant hospitals in t...

Background: Every year, more than 5500 healthy people in the United States donate a kidney for the medical benefit of another person. The Organ Procurement and Transplantation Network (OPTN) requires transplant hospitals to monitor living kidney donors (LKDs) for 2 years postdonation. However, the majority (115/202, 57%) of transplant hospitals in...

Background Frail kidney transplant (KT) recipients may be particularly vulnerable to surgical stressors, resulting in delirium and subsequent adverse outcomes. We sought to identify the incidence, risk factors, and sequelae of post-KT delirium. Methods We studied 125,304 adult KT recipients (1999–2014) to estimate delirium incidence in national reg...

Background: The epidemic of drug overdose deaths in the United States has led to an increase in organ donors. Objective: To characterize donors who died of overdose and to analyze outcomes among transplant recipients. Design: Prospective observational cohort study. Setting: Scientific Registry of Transplant Recipients, 1 January 2000 to 1 Se...

Background: Social media platforms are increasingly used in surgery and have shown promise as effective tools to promote deceased donation and expand living donor transplantation. There is growing need to understand how social media-driven communication is perceived by providers in the field of transplantation. Methods: We surveyed 299 members o...

Background: Among community-dwelling older adults, frailty is associated with heightened markers of inflammation and subsequent mortality. Although frailty is common among ESRD patients, the role of frailty and markers of inflammation in this population remains unclear. We quantified these associations in patients on the kidney transplant (KT) wai...

The practice of kidney paired donation (KPD) is expanding annually, offering the opportunity for live donor kidney transplantation to more patients. We sought to identify if voluntary KPD networks such as the National Kidney Registry (NKR) were selecting or attracting a narrower group of donors or recipients compared to national registries. For thi...

Background: Allografts from older liver donors (OLDs) age≥70 are often discarded for fear of inferior outcomes. We previously identified 'preferred recipients' who did not suffer the higher risk of graft loss and mortality associated with OLDs. Preferred recipients were first-time, non-Status 1 registrants with age>45, BMI<35, indication other tha...

Kidney paired donation (KPD) can facilitate living donor transplantation for candidates with an incompatible donor, but requires waiting for a match while suffering the morbidity of dialysis. The balance between waiting for KPD versus desensitization or deceased donor transplantation relies on the ability to estimate KPD wait times. We studied dono...

Background: The donation of multiple allografts from a single living donor is a rare practice, and the patient characteristics and outcomes associated with these procedures are not well described. Methods: Using the SRTR registry, we identified 101 living multi-organ donors and their 133 recipients. Results: The 49 sequential (donations during...

New regulations require living kidney donor (LKD) follow-up for two years, but donor retention remains poor. Electronic communication (e.g. text messaging, e-mail) might improve donor retention. To explore the possible impact of electronic communication, we recruited LKDs to participate in an exploratory study of communication via telephone, e-mail...

Kidney paired donation (KPD) is an important tool to facilitate living donor kidney transplantation (LDKT). Concerns remain over prolonged cold ischemia times (CIT) associated with shipping kidneys long distances through KPD. We examined the association between CIT and delayed graft function (DGF), allograft survival, and patient survival for 1,267...