Validation of Systemic Lupus Erythematosus Diagnosis as the Primary Cause of Renal Failure in the US Renal Data System

Referral and evaluation for kidney transplantation among patients with lupus nephritis-related end-stage kidney disease

OBJECTIVE

For the majority of patients with lupus nephritis-related end-stage kidney disease (LN-ESKD), kidney transplant is associated with better outcomes than dialysis. Access to kidney transplant requires an initial referral to a transplant center and medical evaluation prior to waitlisting. The study's objective was to examine access to these early steps in the kidney transplant process among patients with LN-ESKD.

METHODS

Adults who began treatment for ESKD in the Southeast, Northeast, New York, or Ohio River Valley U.S. regions from 1/1/2012 to 12/31/2019, followed through 6/30/2021, were identified from the United States Renal Data System. Referral and evaluation start data were collected from 28 of 48 transplant centers across these regions. The exposure was primary cause of ESKD (LN-ESKD vs other-ESKD). The outcomes were referral and evaluation start at a transplant center. Cox models quantified the association between LN-ESKD (vs other-ESKD) and referral and evaluation start.

RESULTS

Among 192,318 patients initiating treatment for ESKD, 0.4% had LN-ESKD. Over half (58%) of LN-ESKD patients were referred before study end, and among those referred, 66% started the evaluation. In adjusted analyses, patients with LN-ESKD were referred (HR: 1.09, 95% CI: 0.99, 1.19) and started the transplant evaluation (HR: 1.13, 95% CI: 1.00, 1.28) at a higher rate than patients with other-ESKD. Among referred patients with LN-ESKD, the median time from ESKD start to referral was 2.9 months (IQR: <1 to 11.7 months), which is similar to patients with other-ESKD (median 2.6 months, IQR: <1 to 8.8 months).

CONCLUSIONS

Among incident patients with ESKD, having a primary diagnosis of LN-ESKD versus other-ESKD is associated with higher rates of early transplant access outcomes. Despite this, patients with LN-ESKD (vs other-ESKD) are less likely to be preemptively referred (i.e., referred prior to ESKD start) for kidney transplant. While providers may no longer be delaying the early steps in the kidney transplantation process among this patient population, there is still room for improvement in the rates of preemptive referral. Access to kidney transplant referral prior to ESKD could result in increased transplant rates and better transplant outcomes for patients with LN-ESKD.

Prescribing Patterns of Hydroxychloroquine and Glucocorticoids Among Lupus Patients After New-Onset End-Stage Renal Disease

OBJECTIVE

Optimal strategies for managing lupus medications after end-stage renal disease (ESRD) have not been addressed. The objective was to identify the current US-wide prescribing patterns of hydroxychloroquine (HCQ) and oral glucocorticoids (GS) among systemic lupus erythematosus (SLE) patients with incident ESRD enrolled in the US Renal Data System (USRDS) registry.

METHODS

We identified incident ESRD patients age ≥18 years with SLE as a primary cause of ESRD between January 2006 and June 2013. Patients who were started on dialysis at ESRD onset and enrolled in Medicare Part D within 93 days as required by Medicare were included.

RESULTS

Among the 2,654 new-onset ESRD patients with Part D, the median duration of follow-up was 761 days (interquartile range [IQR] 374-1,375). At baseline, 1,076 patients (41%) were not receiving HCQ or GS, 220 (8%) were prescribed HCQ alone, 509 (19%) were prescribed both HCQ and GS, and 849 (32%) were prescribed GS alone. Of the 1,983 patients who either never received or discontinued HCQ after ESRD onset, 667 (34%) continued GS to the end of the follow-up period. The median GS dose was lower for patients taking HCQ (14 mg [IQR 9-21]) compared to patients who were never prescribed HCQ (15 mg [IQR 9-27]) or patients who discontinued HCQ after ESRD (17 mg [IQR 10-27]; P = 0.001).

CONCLUSION

Approximately one-third of patients with lupus nephritis and new-onset ESRD received GS monotherapy at high doses. As GS-related complications contribute to hospitalizations and deaths in SLE ESRD, changing these prescribing practices may improve morbidity and mortality outcomes.

Kidney Transplantation and Cardiovascular Events Among Patients With End-Stage Renal Disease Due to Lupus Nephritis: A Nationwide Cohort Study

OBJECTIVE

To assess the potential impact of kidney transplantation on cardiovascular (CV) events among patients with end-stage renal disease (ESRD) due to lupus nephritis (LN).

METHODS

In a nationwide cohort study, we identified all patients with LN-ESRD enrolled in the US Renal Data System who were waitlisted for a kidney transplant and enrolled in Medicare between January, 2000 and December, 2016. The primary outcome was incident CV events, including myocardial infarction (MI) and ischemic cerebrovascular accident (CVA). We used time-dependent Cox regression to estimate the hazard ratios (HRs) of these outcomes associated with kidney transplant as a time-varying exposure, adjusting for sex, age, race, ethnicity, geographic region, year of ESRD onset, first ESRD treatment modality (e.g., hemodialysis or peritoneal dialysis), Charlson Comorbidity Index score, and history of prior organ transplants.

RESULTS

Of 5,963 waitlisted patients with LN-ESRD, 3,209 (54%) had a kidney transplant during the study period. The majority were female (82%), and African American patients represented 48% of waitlisted patients and 43% of transplanted patients. Kidney transplantation was associated with a lower risk of incident CV events (adjusted HR 0.31 [95% confidence interval (95% CI) 0.18-0.53]) as well as lower risks of MI and CVA (adjusted HRs 0.13 [95% CI 0.08-0.34] and 0.30 [95% CI 0.16-0.54], respectively).

CONCLUSION

Kidney transplantation was associated with a reduced risk of CV events, including MI and CVA, in patients with LN-ESRD. Our findings highlight the importance of identifying barriers to transplantation in this population, as improved access could reduce CV morbidity.

Validation of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis as the Cause of End-Stage Renal Disease in the US Renal Data System

Objective

The objective of this study was to validate the diagnosis of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) as the primary cause of end‐stage renal disease (ESRD) in the US Renal Data System (USRDS).

Methods

We identified patients with ESRD in the Mass General Brigham (MGB) health care system who were enrolled in the USRDS. The health records of those with AAV listed as the primary cause of ESRD in the USRDS were reviewed to confirm the diagnosis and estimate positive predictive value (PPV). Sensitivity was estimated by evaluating the primary cause of ESRD listed in the USRDS for patients with ESRD due to AAV in the MGB AAV cohort.

Results

We identified 89 MGB patients with ESRD due to AAV in the USRDS. Of these, 85 cases were confirmed to be true cases of AAV (PPV = 94%). Among the patients classified as having AAV, 84 (99%) had an ANCA test, which was predominantly myeloperoxidase/P‐ANCA (47 [55%]); 36 (42%) had a renal biopsy, and all biopsies were supportive of the diagnosis. The majority (81 [90%]) was identified as AAV by International Classification of Diseases Ninth Revision or International Classification of Diseases 10th Revision codes for granulomatosis with polyangiitis (446.4 or M313.1). Of the 77 MGB AAV cohort patients with ESRD who were linked to the USRDS, 41 (53%) had AAV listed as the cause of ESRD; in the remainder, ESRD was attributed to nonspecific nephritis.

Conclusion

The diagnosis of AAV as the cause of ESRD in the USRDS has a high PPV; sensitivity was moderate. These findings support the continued use of the USRDS to study ESRD due to AAV.

Electronic Medical Record-Based Case Phenotyping for the Charlson Conditions: Scoping Review

Background

Electronic medical records (EMRs) contain large amounts of rich clinical information. Developing EMR-based case definitions, also known as EMR phenotyping, is an active area of research that has implications for epidemiology, clinical care, and health services research.

Objective

This review aims to describe and assess the present landscape of EMR-based case phenotyping for the Charlson conditions.

Methods

A scoping review of EMR-based algorithms for defining the Charlson comorbidity index conditions was completed. This study covered articles published between January 2000 and April 2020, both inclusive. Embase (Excerpta Medica database) and MEDLINE (Medical Literature Analysis and Retrieval System Online) were searched using keywords developed in the following 3 domains: terms related to EMR, terms related to case finding, and disease-specific terms. The manuscript follows the Preferred Reporting Items for Systematic reviews and Meta-analyses extension for Scoping Reviews (PRISMA) guidelines.

Results

A total of 274 articles representing 299 algorithms were assessed and summarized. Most studies were undertaken in the United States (181/299, 60.5%), followed by the United Kingdom (42/299, 14.0%) and Canada (15/299, 5.0%). These algorithms were mostly developed either in primary care (103/299, 34.4%) or inpatient (168/299, 56.2%) settings. Diabetes, congestive heart failure, myocardial infarction, and rheumatology had the highest number of developed algorithms. Data-driven and clinical rule–based approaches have been identified. EMR-based phenotype and algorithm development reflect the data access allowed by respective health systems, and algorithms vary in their performance.

Conclusions

Recognizing similarities and differences in health systems, data collection strategies, extraction, data release protocols, and existing clinical pathways is critical to algorithm development strategies. Several strategies to assist with phenotype-based case definitions have been proposed.

Renal Transplantation and Survival Among Patients With Lupus Nephritis: A Cohort Study

Background

Patients with end-stage renal disease (ESRD) due to lupus nephritis (LN) have high rates of premature death.

Objective

To assess the potential effect on survival of renal transplant among patients with ESRD due to LN (LN-ESRD) in the United States.

Design

Nationwide cohort study.

Setting

United States Renal Data System, the national database of nearly all patients with ESRD.

Participants

Patients with incident LN-ESRD who were waitlisted for a renal transplant.

Measurements

First renal transplant was analyzed as a time-varying exposure. The primary outcomes were all-cause and cause-specific mortality. Time-dependent Cox regression analysis was used to estimate the hazard ratio (HR) of these outcomes associated with renal transplant in the primary analysis. Sequential cohort matching was used in a secondary analysis limited to patients with Medicare, which allowed assessment of time-varying covariates.

Results

During the study period, 9659 patients with LN-ESRD were waitlisted for a renal transplant, of whom 5738 (59%) had a transplant. Most were female (82%) and nonwhite (60%). Transplant was associated with reduced all-cause mortality (adjusted HR, 0.30 [95% CI, 0.27 to 0.33]) among waitlisted patients. Adjusted HRs for cause-specific mortality were 0.26 (CI, 0.23 to 0.30) for cardiovascular disease, 0.30 (CI, 0.19 to 0.48) for coronary heart disease, 0.41 (CI, 0.32 to 0.52) for infection, and 0.41 (CI, 0.31 to 0.53) for sepsis.

Limitation

Unmeasured factors may contribute to the observed associations; however, the E-value analysis suggested robustness of the results.

Conclusion

Renal transplant was associated with a survival benefit, primarily due to reduced deaths from cardiovascular disease and infection. The findings highlight the benefit of timely referral for transplant to improve outcomes in this population.

Primary Funding Source

National Institutes of Health.

Methodological considerations in comparing access to Pre-emptive renal transplantation between SLE and other ESRD causes in the USRDS

BACKGROUND

We compared pre-emptive transplant rates between SLE and non-SLE end-stage renal disease (ESRD) from the U.S. Renal Data System (USRDS) and investigated the potential influence of frequency matching and primary ESRD causes in the non-SLE group.

METHODS

4830 adult SLE patients with incident ESRD from USRDS 2005-2009 were frequency matched by age, sex and race to 4830 patients with incident non-SLE ESRD. Multivariable logistic regression models were used to estimate the odds of pre-emptive transplantation in SLE and non-SLE, and with the non-SLE subgroups by primary ESRD cause.

RESULTS

The odds ratios (OR) of receiving a pre-emptive transplant were similar among non-SLE and SLE (referent group): OR = 1.18 (95% CI: 0.92, 1.50; p = 0.20). However, the ORs for receiving a pre-emptive transplant were 0.19 (95% CI: 0.08, 0.42) in type 2 diabetes ESRD, 0.42 (95% CI: 0.23, 0.75) for hypertension-associated ESRD, 1.67 (95% CI: 1.10, 2.54) in type 1 diabetes ESRD, and 2.06 (95% CI: 1.55, 2.73) for "other" ESRD. In contrast to non-SLE, younger SLE patients were less likely to receive a pre-emptive transplant than older SLE patients.

CONCLUSION

The results of this study provide compelling evidence that major improvements need to be made in optimizing access to pre-emptive transplantation in SLE by addressing sociodemographic disparities and the unique challenges faced by SLE patients. Applying careful matching and selecting appropriate comparison groups in future studies may facilitate the development of effective strategies to address these barriers and to increase the number of pre-emptive renal transplants among SLE patients.

All-Cause and Cause-Specific Mortality Trends of End-Stage Renal Disease Due to Lupus Nephritis From 1995 to 2014

OBJECTIVE

A prior study showed that premature mortality among patients with end-stage renal disease (ESRD) due to lupus nephritis (LN) persisted in the US between 1995 and 2006. The present study was undertaken to extend this analysis through 2014 to examine more recent trends, including key cause-specific mortality trends.

METHODS

Using the national registry of patients with ESRD, we identified all patients with incident ESRD due to LN between January 1, 1995 and December 31, 2014, divided into four 5-year cohorts of ESRD onset by calendar year (1995-1999, 2000-2004, 2005-2009, 2010-2014). We assessed mortality within each cohort. Temporal trends in all-cause mortality and cause-specific mortality were examined, adjusting for covariates.

RESULTS

We identified 20,974 individuals with incident ESRD due to LN from 1995 through 2014. The mortality rate per 100 patient-years declined from 11.1 (95% confidence interval [95% CI] 10.4-11.8) in 1995-1999 to 6.7 (95% CI 6.2-7.2) in 2010-2014 (P for trend < 0.01). Adjusted mortality hazard ratios in 2010-2014, compared with 1995-1999, were 0.68 (95% CI 0.58-0.78) for white patients, 0.67 (95% CI 0.57-0.78) for African American patients, and 0.51 (95% CI 0.38-0.69) for Hispanic patients. Deaths from cardiovascular disease (CVD) and infection declined by 44% and 63%, respectively, from 1995-1999 to 2010-2014 (P for trend < 0.01 for both).

CONCLUSION

In the more recent years of the period 1995-2014, there was a considerable reduction in all-cause mortality among white, African American, and Hispanic patients, with reduced risk of death from CVD and infection. Collectively, these trends provide an important benchmark of improving care in this high-risk population.