The coronavirus disease 2019 pandemic: the disruptor that maintenance dialysis never anticipated.

PURPOSE OF REVIEW: The novel coronavirus 2019 (COVID-19) pandemic has upended maintenance dialysis in the United States. I review changes in prevalence, incidence, mortality, and other clinical outcomes among patients undergoing dialysis since March 2020, highlighting vulnerabilities in the current system and opportunities for improved care in the future. RECENT FINDINGS: The number of dialysis patients in the United States declined between March 2020 and March 2021, an unprecedented year-over-year drop in the census. Some of the decline can be attributed to an early drop in patients initiating dialysis but most of the decline can be attributed to excess mortality. Kidney transplants also declined during the early part of the pandemic. Home dialysis utilization increased during 2020 but that increase was largely in line with secular trends. The rate of hospitalization for causes other than COVID-19 fell significantly during 2020. SUMMARY: The epidemiology of dialysis in the United States is clearly modifiable, as it reflects decisions to initiate treatment, prescribe home therapies, and hospitalize patients with acute medical needs. On the other hand, some outcomes are powerfully guided by health outcomes in the general population, thus limiting the ability of dialysis providers and nephrologists to influence outcomes.

Associations of COVID-19 Outcomes with Dialysis Modalities and Settings.

How maintenance dialysis modality, dialysis setting, and residence in a nursing facility have jointly associated with coronavirus disease 2019 (COVID-19)-related outcomes in the United States is relevant to future viral outbreaks. Using Medicare claims, we determined the incidence of COVID-19-related infection, hospitalization, and death between March 15, 2020 and June 5, 2021. The exposure was one of five combinations of dialysis modality and care setting: in-facility hemodialysis without a recent history of skilled nursing facility care, in-facility hemodialysis with a recent history of skilled nursing facility care, hemodialysis in a skilled nursing facility, home hemodialysis, and (home) peritoneal dialysis. Patient-weeks were pooled to estimate the adjusted associations of event incidence with each dialysis modality/setting during four intervals in 2020-2021. Relative to in-facility hemodialysis without a recent history of skilled nursing facility care, home dialysis was associated with 36%-60% lower odds of all events during weeks 12-23 of 2020; 24%-37% lower odds of all events during weeks 24-37 of 2020; 20%-33% lower odds of infection and hospitalization during the winter of 2020-2021; and similar odds of all events thereafter. In contrast, exposure to skilled nursing facilities was associated with 570%-1140% higher odds of all events during spring of 2020, although excess risk attenuated as the pandemic transpired, especially among patients who received hemodialysis in skilled nursing facilities. In conclusion, home dialysis was associated with lower risks of COVID-19 diagnosis, hospitalization, and death until vaccines were available, whereas care in skilled nursing facilities was associated with higher risks.

Machine Learning for Prediction of Patients on Hemodialysis with an Undetected SARS-CoV-2 Infection.

Background: We developed a machine learning (ML) model that predicts the risk of a patient on hemodialysis (HD) having an undetected SARS-CoV-2 infection that is identified after the following ≥3 days. Methods: As part of a healthcare operations effort, we used patient data from a national network of dialysis clinics (February-September 2020) to develop an ML model (XGBoost) that uses 81 variables to predict the likelihood of an adult patient on HD having an undetected SARS-CoV-2 infection that is identified in the subsequent ≥3 days. We used a 60%:20%:20% randomized split of COVID-19-positive samples for the training, validation, and testing datasets. Results: We used a select cohort of 40,490 patients on HD to build the ML model (11,166 patients who were COVID-19 positive and 29,324 patients who were unaffected controls). The prevalence of COVID-19 in the cohort (28% COVID-19 positive) was by design higher than the HD population. The prevalence of COVID-19 was set to 10% in the testing dataset to estimate the prevalence observed in the national HD population. The threshold for classifying observations as positive or negative was set at 0.80 to minimize false positives. Precision for the model was 0.52, the recall was 0.07, and the lift was 5.3 in the testing dataset. Area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC) for the model was 0.68 and 0.24 in the testing dataset, respectively. Top predictors of a patient on HD having a SARS-CoV-2 infection were the change in interdialytic weight gain from the previous month, mean pre-HD body temperature in the prior week, and the change in post-HD heart rate from the previous month. Conclusions: The developed ML model appears suitable for predicting patients on HD at risk of having COVID-19 at least 3 days before there would be a clinical suspicion of the disease.

Catheter-Associated Bloodstream Infections among Patients on Hemodialysis: Progress before and during the COVID-19 Pandemic.

Measures implemented to prevent transmission of severe acute respiratory syndrome coronavirus 2 in outpatient dialysis facilities may also help to prevent catheter-associated bloodstream infections in patients receiving hemodialysis. We used United States Renal Data System data to examine rates of antibiotic administration within dialysis facilities and rates of hospital admission for catheter-associated bloodstream infection from March 2018 through November 2020, and rates of hospitalization for sepsis, to address overall changes in hospitalization during the coronavirus disease 2019 (COVID-19) pandemic. Using logistic regression, we estimated year-over-year adjusted odds ratios of these events in 3-month intervals. During the first 6 months of the pandemic, rates of antibiotic administration were between 20% and 21% lower, and rates of hospitalization for catheter-associated bloodstream infection were between 17% and 24% lower than during corresponding periods in 2019, without significant changes in rates of hospitalization for sepsis. However, rates of catheter-associated events also decreased between 2018 and 2019, driven by reductions in facilities operated by a large dialysis provider. These data suggest that significant reductions in catheter-associated infections occurred during the pandemic, superimposed on nonpandemic-related reductions in some facilities before the pandemic. Even after the pandemic, it may be prudent to continue some COVID-19 mitigation measures to prevent catheter-associated bloodstream infections.

Changes in Treatment of Patients with Incident ESKD during the Novel Coronavirus Disease 2019 Pandemic.

BACKGROUND: The COVID-19 pandemic caused major disruptions to care for patients with advanced CKD. METHODS: We investigated the incidence of documented ESKD, ESKD treatment modalities, changes in eGFR at dialysis initiation, and use of incident central venous catheters (CVCs) by epidemiologic week during the first half of 2020 compared with 2017-2019 historical trends, using Centers for Medicare and Medicaid Services data. We used Poisson and logistic regression for analyses of incidence and binary outcomes, respectively. RESULTS: Incidence of documented ESKD dropped dramatically in 2020 compared with the expected incidence, particularly during epidemiologic weeks 15-18 (April, incidence rate ratio [IRR], 0.75; 95% CI, 0.73 to 0.78). The decrease was most pronounced for individuals aged ≥75 years (IRR, 0.69; 95% CI, 0.66 to 0.73). Pre-emptive kidney transplantation decreased markedly during weeks 15-18 (IRR, 0.56; 95% CI, 0.46 to 0.67). Mean eGFR at dialysis initiation decreased by 0.33 ml/min per 1.73 m2 in weeks 19-22; non-Hispanic Black patients exhibited the largest decrease, at 0.61 ml/min per 1.73 m2. The odds of initiating dialysis with eGFR <10 ml/min per 1.73 m2 were highest during weeks 19-22 (May, OR, 1.14; 95% CI, 1.05 to 1.17), corresponding to an absolute increase of 2.9%. The odds of initiating peritoneal dialysis (versus hemodialysis) were 24% higher (OR, 1.24; 95% CI, 1.14 to 1.34) in weeks 11-14, an absolute increase of 2.3%. Initiation with a CVC increased by 3.3% (OR, 1.30; 95% CI, 1.20 to 1.41). CONCLUSIONS: During the first wave of the COVID-19 pandemic, the number of patients starting treatment for ESKD fell to a level not observed since 2011. Changes in documented ESKD incidence and other aspects of ESKD-related care may reflect differential access to care early in the pandemic.

Initial Effects of COVID-19 on Patients with ESKD.

BACKGROUND: Reports from around the world have indicated a fatality rate of patients with coronavirus disease 2019 (COVID-19) in the range of 20%-30% among patients with ESKD. Population-level effects of COVID-19 on patients with ESKD in the United States are uncertain. METHODS: We identified patients with ESKD from Centers for Medicare and Medicaid Services data during epidemiologic weeks 3-27 of 2017-2020 and corresponding weeks of 2017-2019, stratifying them by kidney replacement therapy. Outcomes comprised hospitalization for COVID-19, all-cause death, and hospitalization for reasons other than COVID-19. We estimated adjusted relative rates (ARRs) of death and non-COVID-19 hospitalization during epidemiologic weeks 13-27 of 2020 (March 22 to July 4) versus corresponding weeks in 2017-2019. RESULTS: Among patients on dialysis, the rate of COVID-19 hospitalization peaked between March 22 and April 25 2020. Non-Hispanic Black race and Hispanic ethnicity associated with higher rates of COVID-19 hospitalization, whereas peritoneal dialysis was associated with lower rates. During weeks 13-27, ARRs of death in 2020 versus 2017-2019 were 1.17 (95% confidence interval [95% CI], 1.16 to 1.19) and 1.30 (95% CI, 1.24 to 1.36) among patients undergoing dialysis or with a functioning transplant, respectively. Excess mortality was higher among non-Hispanic Black, Hispanic, and Asian patients. Among patients on dialysis, the rate of non-COVID-19 hospitalization during weeks 13-27 in 2020 was 17% lower versus hospitalization rates for corresponding weeks in 2017-2019. CONCLUSIONS: During the first half of 2020, the clinical outcomes of patients with ESKD were greatly affected by COVID-19, and racial and ethnic disparities were apparent. These findings should be considered in prioritizing administration of COVID-19 vaccination.