Understanding the Burden of the COVID-19 Pandemic for People With Kidney Disease

Clinical Outcomes and Vaccine Effectiveness for SARS-CoV-2 Infection in People Attending Advanced CKD Clinics: A Retrospective Provincial Cohort Study

BACKGROUND

People with advanced CKD are at high risk of mortality and morbidity from coronavirus disease 2019 (COVID-19). We measured rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe outcomes in a large population attending advanced CKD clinics during the first 21 months of the pandemic. We examined risk factors for infection and case fatality, and we assessed vaccine effectiveness in this population.

METHODS

In this retrospective cohort study, we analyzed data on demographics, diagnosed SARS-CoV-2 infection rates, outcomes, and associated risk factors, including vaccine effectiveness, for people attending a province-wide network of advanced CKD clinics during the first four waves of the pandemic in Ontario, Canada.

RESULTS

In a population of 20,235 patients with advanced CKD, 607 were diagnosed with SARS-CoV-2 infection over 21 months. The case fatality rate at 30 days was 19% overall but declined from 29% in the first wave to 14% in the fourth. Hospitalization and intensive care unit (ICU) admission rates were 41% and 12%, respectively, and 4% started long-term dialysis within 90 days. Significant risk factors for diagnosed infection on multivariable analysis included lower eGFR, higher Charlson Comorbidity Index, attending advanced CKD clinics for more than 2 years, non-White ethnicity, lower income, living in the Greater Toronto Area, and long-term care home residency. Being doubly vaccinated was associated with lower 30-day case fatality rate (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.03 to 0.52). Older age (OR, 1.06 per year; 95% CI, 1.04 to 1.08) and higher Charlson Comorbidity Index (OR, 1.11 per unit; 95% CI, 1.01 to 1.23) were associated with higher 30-day case fatality rate.

CONCLUSIONS

People attending advanced CKD clinics and diagnosed with SARS-CoV-2 infection in the first 21 months of the pandemic had high case fatality and hospitalization rates. Fatality rates were significantly lower in those who were doubly vaccinated.

PODCAST

This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_04_10_CJN10560922.mp3.

BNT162b2 vaccine effectiveness in chronic kidney disease patients – an observational study

Background

chronic kidney disease (CKD) is a risk factor for severe COVID-19. We aimed to evaluate real-life effectiveness of the BNT162b2 mRNA vaccine for a range of outcomes in patients with CKD compared to matched controls.

Methods

Data from Israel's largest healthcare organization were retrospectively used. Vaccinated CKD (eGFR<60ml/min/1.73m2) and maintenance dialysis patients were matched to vaccinated controls without CKD (eGFR> = 60ml/min/1.73m2) according to demographic and clinical characteristics. Study outcomes included documented infection with SARS-CoV-2, symptomatic infection, COVID-19 related hospitalization, severe disease, and death. Vaccine effectiveness was estimated as the risk ratio [RR] at days 7-28 following the second vaccine dose, using the Kaplan–Meier estimator. Effectiveness measures were also evaluated separately for various stages of CKD.

Results

There were 67,861 CKD patients not treated with dialysis, 2,606 hemodialysis patients, and 70,467 matched controls. The risk of sever disease (RR1.84, 95% CI 0.95-2.67) and death (RR 2.00, 95% CI 0.99-5.20) was increased in non-dialysis CKD patients compared with controls without CKD following vaccination.

For the subgroup of patients with eGFR below 30 ml/min/1.73m2, the risk of severe disease and death was increased compared to controls (RR 6.42, 95% CI 1.85-17.51 and RR 8.81, 95% CI 1.63-13.81, respectively). The risks for all study outcomes was increased in hemodialysis patients, compared with controls.

Conclusion

Two doses of the BNT162b2 vaccine were found less efficient for patients with eGFR<30ml/min/1.73m2. Risk in hemodialysis patients is increased for all outcomes. These results suggest prioritizing patients with eGFR<30ml/min/1.73m2 for booster shots, pre and post exposure prophylaxis, and early COVID-19 therapy.