Severity of COVID-19 in end-stage kidney disease patients on chronic dialysis.

Dear Editor,

There were some contentious issues concerning the severity of COVID‐19 among end‐stage kidney disease (ESKD) patients on chronic dialysis when an initial study reported a lesser severity of COVID‐19 among those individuals. To clarify this, we conducted a systematic review to explore the prevalence of severe COVID‐19 and the mortality rate of COVID‐19 among ESKD patients on chronic dialysis.

A literature search was performed of the electronic databases PubMed and the Cochrane Central Database, with the specific terms (“COVID‐19” OR “SARS‐CoV‐2”) AND (“ESKD” OR “End‐Stage Kidney Disease” OR “End‐Stage Renal Disease” OR “ESRD”) AND (“Dialysis” OR “Hemodialysis”). A time restriction was applied from the date of inception to August 20, 2020, which was the date of our search finalization. All research articles in which the subjects were adult ESKD patients with COVID‐19 on chronic dialysis were independently sorted, screened, and examined for relevance. Meta‐analysis of proportion was conducted using MedCalc Statistical Software version 19.4.1 (MedCalc Software Ltd, Ostend, Belgium).

Overall, 381 publications were initially identified based on the search criteria and 26 articles were removed because of duplication. Then, of the remaining 355, 339 articles were excluded after title and abstract screening. After analyzing the remaining 16 full‐text articles, six studies were removed because of the unavailability of data regarding severity or mortality of COVID‐19 among ESKD patients on chronic dialysis. Finally, 10 articles were included in this analysis.

The characteristics of included studies are summarized in Table 1.1, 2, 3, 4, 5, 6, 7, 8, 9, 10 The overall prevalence of COVID‐19 among dialysis patients, rates of severe COVID‐19 and mortality among hospitalized ESKD patients on chronic dialysis in this study were 18.4% (95% confidence interval [CI] 6.0‐35.0, I 2 = 97.32%, P < .0001), 45.3% (95% CI 26.5‐64.9, I 2 = 93.36%, P < .0001), and 26.8% (95% CI 19.2‐35.1, I 2 = 67.74%, P = .0017), respectively. While the severity of COVID‐19 was relatively similar across the globe, the mortality rate was strikingly lower in Asia (11.48%, 95% CI 4.8‐20.4, I 2 = 0%, P = .5879), compared to Europe (39.1%, 95% CI 30.7‐48.0, I 2 = 0%, P = .4565) and the United States (31.7%, 95% CI 27.6‐35.9, I 2 = 0%, P = .8813).

TABLE 1

Characteristics of included studies

Author	Location	Study	Period	Hospitalized dialysis patients with COVID‐19	All dialysis patients with COVID‐19 (including outpatients)	Total dialysis patients	Age a	Male (%)	Severe b (%)	In‐hospital mortality (%)
Valeri et al 2	United States	Retrospective	March 9 to April 8, 2020	59	NA	NA	63 (56‐78)	33/59 (56)	19/59 (33)	18/59 (31)
Naaraayan et al 3	United States	Retrospective	March 12 to May 13, 2020	27	NA	NA	NA	NA	15/27 (44.4)	NA
Ng et al 4	United States	Retrospective	March 1 to April 27, 2020	419	NA	NA	66 (55‐75)	260/419 (62.1)	89/419 (21.2)	133/419 (31.7)
Yau et al 5	Canada	Retrospective	April 7 to 22, 2020	5	11	237	66 (63‐72)	5/11 (55)	2/11 (18)	0
Alberici et al 6	Italy	Prospective	March 1 to April 3, 2020	57	94	643	72 (62‐79)	62/94 (65.9)	45/94 (47.8)	24/57 (42.1)
Goicoechea et al 7	Spain	Retrospective	March 12 to April 10, 2020	36	36	282	71 (12)	23/36 (63.8)	12/36 (33.3)	11/36 (30.5)
Mazzoleni et al 8	Belgium	Retrospective	March 6 to April 14, 2020	25	40	62	75 (68‐83)	23/40 (57.5)	22/40 (55.0)	11/25 (44.0)
Ma et al 1	China	Retrospective	January 14 to March 12, 2020	15	15	230	71 (54‐76)	10/15 (66.7)	3/15 (20)	2/15 (13.3)
Zhang et al 9	China	Retrospective	NA	31	NA	NA	62.3 (14.4)	18/31 (58.1)	12/31 (38.7)	2/31 (6.5)
Jung et al 10	South Korea	Retrospective	February to April, 2020	14	14	NA	63.5 (14.5)	6/14 (42.9)	5/14 (35.7)	2/14 (14.3)

Abbreviations: COVID‐19, coronavirus disease 2019; ESKD, end‐stage kidney disease; NA, not available.

Data are presented either with mean (SD) or median (interquartile range).

Severe definition: The presence of acute respiratory distress syndrome, mechanical ventilation, respiratory failure, admittance to intensive care unit, or oxygen saturation of <93% (on room air).

Based on our study, we found that ESKD patients on dialysis are highly susceptible to contracting severe COVID‐19 with a substantially increased risk of mortality compared to the general population across the globe. Hypothetically, this is due to immunocompromised state along with multiple comorbidities in this specific population. Interestingly, the in‐hospital mortality rate in Asia was reported to be lower compared to Europe or the United States. While the definite causes of the disparity in the mortality rate in those geographical region are still unknown, several possible hypotheses are suggested, including mutational variants of SARS‐CoV‐2, genetic factors, body mass index, and other demographic factors. The initial data showing lower severity and mortality of COVID‐19 among ESKD patients on chronic dialysis have misled many authors to believe that ESKD patients might have special characteristics which could reduce the severity of COVID‐19. Our findings clarified this contentious issue and further confirmed the evidence for the utmost necessity of additional COVID‐19 precautions in HD centers.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

DATA AVAILABILITY

The data used to support the findings of this study are included within the article.