Related Experiment Video
Updated: Aug 30, 2025
A Retrograde Implantation Approach for Peritoneal Dialysis Catheter Placement in Mice
Published on: July 20, 2022
COVID-19 and Hospitalization Among Maintenance Dialysis Patients: A Retrospective Cohort Study Using Time-Dependent
Xuemei Ding1,2, Xi Wang1, Garrett W Gremel1
1Kidney Epidemiology and Cost Center, School of Public Health, University of Michigan, Ann Arbor, Michigan.
Insights
COVID-19 significantly increased hospitalization risks for dialysis patients in 2020. Risks were highest initially after diagnosis, remaining elevated long-term, indicating a persistent impact on this vulnerable population.
Area of Science:
- Nephrology
- Infectious Diseases
- Public Health
Background:
- The COVID-19 pandemic disproportionately affected hospitalizations, especially for patients undergoing dialysis.
- Understanding the temporal impact of COVID-19 on dialysis patient hospitalizations is crucial for public health strategies.
Purpose of the Study:
- To model and analyze the impact of coronavirus disease 2019 (COVID-19) on hospitalization rates among dialysis patients in 2020.
- To quantify the varying risks of hospitalization across different stages of COVID-19 infection in dialysis patients.
Main Methods:
- A retrospective cohort study design was employed, analyzing Medicare patients on dialysis in 2020.
- A proportional rate model with a nonparametric baseline rate function was used to assess hospitalization sequences.
- Patients were categorized into four COVID-19 stages: COVID1, COVID2, Post-COVID, and Late-COVID, alongside demographic and clinical characteristics.
Main Results:
- The study included 509,609 dialysis patients, with 63,521 infected with SARS-CoV-2.
- Compared to no COVID-19, hospitalization risks were significantly elevated across all stages: COVID1 (RR 18.50), COVID2 (RR 2.03), Post-COVID (RR 1.37), and Late-COVID (RR 2.00).
- A marked time dependence was observed, with extremely high initial risks followed by moderate, persistent elevated risks.
Conclusions:
- COVID-19 exerts a significant and lasting influence on hospitalization risk in dialysis patients.
- The risk of hospitalization remains elevated even in the Post-COVID and Late-COVID stages, never returning to pre-infection levels.
- These findings highlight the critical need for ongoing monitoring and management of COVID-19 in dialysis populations.
Rationale & Objective:
The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on hospitalizations in general and on dialysis patients in particular. This study modeled the impact of COVID-19 on hospitalizations of dialysis patients in 2020.
Study Design:
Retrospective cohort study.
Setting & Participants:
Medicare patients on dialysis in calendar year 2020.
Predictors:
COVID-19 status was divided into 4 stages: COVID1 (first 10 days after initial diagnosis), COVID2 (extends until the Post-COVID stage), Post-COVID (after 21 days with no COVID-19 diagnosis), and Late-COVID (begins after a hospitalization with a COVID-19 diagnosis); demographic and clinical characteristics; and dialysis facilities.
Outcome:
The sequence of hospitalization events.
Analytical Approach:
A proportional rate model with a nonparametric baseline rate function of calendar time on the study population.
Results:
A total of 509,609 patients were included in the study, 63,521 were observed to have a SARS-CoV-2 infection, 34,375 became Post-COVID, and 1,900 became Late-COVID. Compared with No-COVID, all 4 stages had significantly greater adjusted risks of hospitalizations with relative rates of 18.50 (95% CI, 18.19-18.81) for COVID1, 2.03 (95% CI, 1.99-2.08) for COVID2, 1.37 (95% CI, 1.35-1.40) for Post-COVID, and 2.00 (95% CI, 1.89-2.11) for Late-COVID.
Limitations:
For Medicare Advantage patients, we only had inpatient claim information. The analysis was based on data from the year 2020, and the effects may have changed due to vaccinations, new treatments, and new variants. The COVID-19 effects may be somewhat overestimated due to missing information on patients with few or no symptoms and possible delay in COVID-19 diagnosis.
Conclusions:
We discovered a marked time dependence in the effect of COVID-19 on hospitalization of dialysis patients, beginning with an extremely high risk for a relatively short period, with more moderate but continuing elevated risks later, and never returning to the No-COVID level.
Related Concept Videos
01:27Dialysis
Acute kidney injury develops suddenly and can be caused by pre-renal causes (e.g., hypovolemia, shock), intrinsic renal causes (e.g., acute tubular necrosis), or post-renal causes (e.g., urinary obstruction). In contrast, chronic renal failure progresses gradually over time and is often...
01:25Hemodialysis III: Nursing Management
01:24Hemodialysis II: Procedure and Complications
01:25Hemodialysis I: Introduction
01:18Chronic Kidney Disease IV: Nursing Management
01:28Chronic Kidney Disease III: Interprofessional Care