Faculty Bibliography

BACKGROUND:Extensive literature has highlighted the psychological burden experienced by kidney transplant recipients (KTRs) and its association with adverse outcomes. Psychological resilience can serve as a measure of baseline vulnerability, and low resilience is associated with poor mental health. We aimed to synthesize the existing literature that has explored the concept of resilience in kidney transplantation. METHODS:A scoping review was conducted due to the anticipated heterogeneity of the literature. Any empirical study that measured resilience using a validated tool in KTRs was included. Resilience could be a variable, a predictor, or an outcome. All study designs were considered with no time restrictions. RESULTS:Of the 4525 titles and abstracts screened, 14 were eligible for inclusion. Sample sizes ranged from 10 to 505 KTRs. One study exclusively focused on developing and validating a resilience scale while others used existing tools. Three studies compared resilience between different populations and the results were heterogeneous: similar resilience between KTRs and dialysis/pre-KT patients (n = 2) and another reporting better resilience in KTRs (n = 1). A decline in resilience scores after pediatric-adult transition (n = 1) and 3 months post-transplant (n = 1) was reported. In terms of outcomes, higher resilience was associated with medication adherence (n = 1), lower frailty (n = 2), and lower risk of psychopathology (n = 2). Two of the three included studies reported improvements in resilience scores with an exercise program and a resilience-enhancing program. CONCLUSIONS:Our review highlights that resilience is an underused and poorly explored construct in KTRs. We recommend explorative and interventional work as resilience is measurable and modifiable.

BACKGROUND:To encourage high-quality, reduced-cost care for total joint arthroplasty (TJA), the Centers of Medicare & Medicaid Services mandated a pay-for-performance model, the Comprehensive Care for Joint Replacement (CJR), as part of the Patient Protection and Affordable Care Act (PPACA). The CJR incentivizes cost containment, and it was anticipated that its implementation would reduce access to TJA for high-cost populations. Patients with end-stage kidney disease (ESKD) undergoing kidney replacement therapy (dialysis and kidney transplant) are costly compared with healthier patients, but it was unknown whether this population lost access to hip and knee replacement because of CJR implementation. This population allows study of whether TJA is accessible for medically complex patients whose risk of surgical complications has been mitigated, as kidney transplantation improves outcomes compared with dialysis, allowing evaluation as to whether access improved when patients crossed over from dialysis to transplantation. Because all patients with ESKD are included in a mandated national registry, we can quantify whether access changed for patients who underwent dialysis and transplantation. QUESTIONS/PURPOSES/OBJECTIVE:(1) How did the rate of TJA change amid the shift to bundled payments for patients with ESKD receiving dialysis? (2) How did the rate of TJA change amid the shift to bundled payments for patients with ESKD after kidney transplant? METHODS:This was an observational cohort study from 2008 to 2018 using the United States Renal Data System, a mandatory national registry that allows for the opportunity to study all individuals with ESKD. During the study period, we identified 1,324,614 adults undergoing routine dialysis and 187,212 adult kidney transplant recipients; after exclusion for non-Medicare primary insurance (n = 785,224 for dialysis and 78,011 for transplant), patients who were 100 years or older (n = 79 and 0, respectively), those who resided outside of 50 US states and Puerto Rico (n = 781 and 87, respectively), missing dialysis status for the dialysis cohort (n = 8658), and multiorgan transplant recipients for the transplant cohort (n = 2442), our study population was 40% (529,872) of patients who underwent routine dialysis and 57% (106,672) of adult kidney transplant recipients, respectively. TJA was ascertained using Medicare Severity Diagnosis Related Groups and ICD-9 and ICD-10 codes. We divided the study period by PPACA (January 1, 2014, to March 31, 2016) and CJR (April 1, 2016, to December 31, 2018) implementation and compared the incidence of TJA by era using mixed-effects Poisson regression adjusting for calendar time and clinical and demographic variables. RESULTS:After adjustment for linear temporal trend and patient case mix, there was no evidence of association between policy implementation and the incidence of TJA. In the dialysis cohort, the adjusted incidence rate ratio (IRR) for TJA was 1.06 (95% confidence interval [CI] 0.98 to 1.14; p = 0.2) comparing PPACA with the previous period and 1.02 (95% CI 0.96 to 1.08; p = 0.6) comparing CJR with the previous periods. Similarly, in the transplant cohort, the adjusted IRR for TJA was 0.82 (95% CI 0.67 to 1.02; p = 0.07) comparing PPACA with the previous period and 1.10 (95% CI 0.94 to 1.28; p = 0.9) comparing CJR with the previous periods. CONCLUSION/CONCLUSIONS:There was no loss in access to TJA for medically complex patients receiving kidney replacement therapy. The increase in TJA incidence for patients after kidney transplant and decrease for patients receiving dialysis suggest that surgeons continued to provide care for higher risk patients whose risk of morbidity or mortality with total joint replacement has been maximally improved after transplantation. LEVEL OF EVIDENCE/METHODS:Level III, prognostic study.

PURPOSE OF REVIEW/OBJECTIVE:Despite emerging studies on neighborhood-level risk factors for chronic kidney disease (CKD), our understanding of the causal links between neighborhood characteristics and CKD is limited. In particular, there is a gap in identifying modifiable neighborhood factors, such as the built environment, in preventing CKD, that could be targets for feasible place-based interventions. RECENT FINDINGS/RESULTS:Most published studies on neighborhood factors and CKD have focused on a single social attribute, such as neighborhood disadvantage, while research on the role of the built environment is more nascent. Early studies on this topic have yielded inconsistent results, particularly regarding whether food deserts are an environmental risk factor for CKD onset. International studies have shown that walkable neighborhoods - characterized by features such as urban design, park access, and green spaces - can be protective against both the onset and progression of CKD. However, these findings are inconclusive and understudied in the context of United States, where neighborhood environments differ from those in other countries. SUMMARY/CONCLUSIONS:Future research on modifiable neighborhood factors and CKD using advanced study designs and population-representative datasets can yield stronger evidence on potential causal associations and suggest feasible place-based interventions as strategies for preventing CKD. As an example, we demonstrated the potential of electronic health record-based studies to advance research in this area.

Unauthorized immigrants and permanent residents may experience challenges in accessing kidney transplantation due to limited healthcare access, socioeconomic and cultural barriers. Understanding the United States (US) national landscape of kidney transplantation for non-citizens may inform policy changes. To evaluate this, we utilized two cohorts from the US national registry (2013-2023): 287,481 adult candidates for first transplant listing and 190,176 adult first transplant recipients. Citizenship was categorized as US citizen (reference), permanent resident, and presumed unauthorized immigrant. Negative binomial regression was used to quantify the incidence rate ratio over time by citizenship status. Cause-specific hazards models, with clustering at the state of listing/transplant, were used to calculate the adjusted hazard ratio of waitlist mortality, kidney transplant, and post-transplant outcomes (mortality/death-censored graft failure) by citizenship category. The crude proportion of presumed unauthorized immigrants listed increased over time (2013: 0.9%, 2023:1.9%). However, after accounting for case mix and waitlist size, there was no change in listing over time. Presumed unauthorized immigrants were less likely to experience waitlist mortality (adjusted Hazard Ratio 0.54, 95% Confidence Interval: 0.46-0.62), were more likely to obtain deceased donor kidney transplant (1.11: 1.05-1.18), but less likely to receive live donor (0.80: 0.71-0.90) or preemptive kidney transplant (0.52: 0.43- 0.62). When stratified by insurance status, presumed unauthorized immigrants on Medicaid were less likely to receive deceased donor kidney transplants compared to their citizen counterparts; however, presumed unauthorized immigrants with Private insurance or Medicare were more likely to receive deceased donor kidney transplants. Presumed unauthorized immigrants were less likely to experience post-transplant death (0.56: 0.43-0.69) and graft failure (0.69: 0.57-0.84). Residents had similar pre- and post-transplant outcomes. Despite the barriers to kidney transplantation faced by presumed unauthorized immigrants and residents in the US, better post-transplant outcomes for presumed unauthorized immigrants compared to citizens persisted, even after accounting for differences in patient characteristics.

BACKGROUND:Cognition is a research priority for people living with chronic kidney disease (CKD), but identification of critical research questions is lacking. This study aimed to determine which cognition-related research questions are most important to CKD stakeholders. METHODS:A modified Delphi technique with 3 survey rounds was used. The study sample included 3 panels (People with lived CKD experience, Researchers, and Clinicians) recruited through international patient and kidney research networks, kidney societies, and snowball sampling with email invitations. Survey rounds were distributed electronically through REDCap. In Round 1 (October 2021-May 2022), respondents contributed three important research questions regarding cognition in CKD (free text). After deduplication and qualitative synthesis, respondents ranked the importance of these questions on a nine-point Likert scale in Round 2 (Feb-April 2023). Questions with mean and median ratings of >7 by at least two respondent panels or rated critically important by the 'lived experience' panel were re-ranked in Round 3 ( Aug-Sept 2023) and assessed for consensus to identify the final list of priority research questions. RESULTS:Respondents (n=152) identified 125 and 44 discrete questions after Rounds 1 and 2, respectively. The final shortlist included 27 questions in 8 categories. The most critical research question identified was "What factors prevent cognitive impairment in people receiving dialysis?" Overall, respondents prioritized questions focusing on prevention and treatment of cognitive impairment. Scores between the panels were significantly different for 16 questions. Those with lived CKD experience prioritized quality of life, researchers emphasized developing interventions to mitigate cognitive impairment, and clinicians prioritized the effect of CKD treatment on cognitive impairment. CONCLUSIONS:Through an established consensus methodology involving key stakeholder groups, we identified 27 critical research questions about cognition in CKD. These questions should guide future study design and outcome selection.

The rise in the mean age of the global population has led to an increase in older kidney transplant (KT) patients. This demographic shift, coupled with the ongoing organ shortage, requires a nuanced understanding of which older adults are most suitable for KT. Recognizing the increased heterogeneity among older adults and the limitations of solely relying on chronological age, there is a need to explore alternative aging metrics beyond chronological age. In this review, we discuss the impact of older age on access to KT and postoperative outcomes. Emphasizing the need for a comprehensive evaluation that extends beyond chronological age, we explore alternative aging metrics such as frailty, sarcopenia, and cognitive function, underscoring their potential role in enhancing the KT evaluation process. Most importantly, we aim to contribute to the ongoing discourse, fostering an optimized approach to KT for the rapidly growing population of older adults.

Frailty is a multi-system syndrome of decreased physiologic reserve that has been shown to strongly and independently predict morbidity and mortality. Frailty is prevalent in patients living with kidney disease and occurs earlier in individuals with kidney disease as compared to the general population. In this comprehensive review, we aim to advance the clinical and research applications of frailty in kidney disease populations. Specifically, we clarify the definition of frailty and address its common misconceptions; review the mechanisms and epidemiology of frailty in kidney disease; discuss challenges and limitations in frailty measurement; and provide updated evidence related to risk factors for frailty, its associated adverse outcomes, and interventions. We further add to the literature in this topic by highlighting potential applications of frailty measurement in care of patients with kidney disease and conclude with our recommendations for future research related to this important syndrome.

Central body fat distribution affects kidney function. Abdominal fat measurements using computed tomography (CT) may prove superior in assessing body composition-related kidney risk in living kidney donors. This retrospective cohort study including 550 kidney donors aimed to determine the association between CT-measured abdominal fat areas and kidney function before and after donor nephrectomy. Donors underwent glomerular filtration rate measurements (¹²⁵I-Iothalamate, mGFR) before and 3 months after donation. Linear regression analyses with body surface area (BSA)-standardized and crude mGFR were performed to assess the association of height-indexed tomographic fat measurements with kidney function. In age-, and sex-adjusted analyses higher levels of total abdominal, visceral, subcutaneous, and intramuscular adipose tissue index were significantly associated with lower mGFR levels before donation (BSA-standardized mGFR: visceral adipose tissue index: Βeta=-0.11, p < 0.001, subcutaneous: Βeta=-0.10, p < 0.001, intramuscular: Βeta=-1.18, p < 0.001, total abdominal: Βeta=-0.07, p < 0.001). Higher tomographic abdominal fat is associated with lower BSA-standardized mGFR after donation and a greater decrease in mGFR between screening and 3 months post-donation. This study shows that CT-measured abdominal fat area is associated with kidney function before and after living kidney donation.