key: cord-310997-ulgemn42
authors: Swai, Joel
title: Letter to the editor—Mortality rate of acute kidney injury in SARS, MERS, and COVID-19 infection: a systematic review and meta-analysis
date: 2020-09-11
journal: Crit Care
DOI: 10.1186/s13054-020-03239-0
sha: 
doc_id: 310997
cord_uid: ulgemn42

nan

Letter to the editor-Mortality rate of acute kidney injury in SARS, MERS, and COVID-19 infection: a systematic review and metaanalysis Joel Swai * Dear Editor, I have read with interest the published article entitled "Mortality rate of acute kidney injury in SARS, MERS, and COVID-19 infection: a systematic review and metaanalysis" by Chen et al. [1] . The article is well written, and I have three concerns as explained below.

Firstly, the mortality rate for COVID-19 patients with AKI is different in the text (i.e., 76.5%; 95% CI 61.0-89.0) from one reported in the authors' Figure 1 (i.e., 78.0%; 95% CI 63.0-90.0). The authors might need to clarify this discrepancy.

Secondly, the authors mistakenly made a duplicate entry of the study by Chen et al. (2020) in the COVID-19 forest plot. This mistake resulted in a pooled AKI mortality rate of 78.0% (CI 63.0-90.0), I 2 = 97.1%, P < 0.0001, instead of 53.99% (CI 52.34-55.65), I 2 = 98.4%, P < 0.0001, had the authors sorted the duplicate-entry problem.

Thirdly, the authors concluded the mortality rate for COVID-19 patients with AKI from an otherwise a high heterogeneity of I 2 = 97.1%, P < 0.0001. This strongly impacts the reliability of the conclusion drawn [2] .

I, on the other hand, reanalyzed authors' data and performed sensitivity analysis according to the Cochrane Library recommendation [3] [4, 5] . The nine remaining studies represented all-Asian Chinese hospitalized patients with COVID-19 and AKI. The newly obtained mortality rate for COVID-19 patients with AKI was 94.90% (CI 91.47-98.34), with nonstatistically significant heterogeneity, I 2 = 7.4%, P < 0.375, see Fig. 1 . Sensitivity analysis could not be conducted in MERS and SARS outcomes because of an insufficient number of studies.

Authors' response to "Joel Swai. Letter to the editor-Mortality rate of acute kidney injury in SARS, MERS, and COVID-19 infection: a systematic review and meta-analysis"

We thank Dr. Joel Swai for the interest in our research letter. As the author pointed out, the reported results of mortality rate for coronavirus disease 2019 (COVID-19) patients with acute kidney injury (AKI) is different from the text and Figure 1c in the original publication of our article [1] . The problem is that we mistakenly made a duplicate entry of the Chen et al. (2020) study while performing the COVID-19 forest plot. We have noticed this critical issue and sent the correct proof before the article publication; unfortunately, this mistake had not been accurately revised by the production team. We sincerely regret the inaccuracy may cause any inconvenience to the readers. However, there are no changes to the interpretation of the results, conclusions, and applications of our article. In details:

1. There was no evidence of statistical heterogeneity among studies reporting AKI mortality in SARS (I 2 = 0.0%, P = 0.589) and MERS (I 2 = 0.0%, P = 0.758), but there was for COVID-19 infection (I 2 = 97.0%, P < 0.0001). 2. Figure 1c :

In addition, our research letter aimed to overview the AKI mortality in patients with different coronaviruses, but the clinical heterogeneity between studies should be also noted. One of the important factors may be the racial difference between studies as Dr. Joel Swai noted. Even if the recent study from Fisher et al. indicated the races are not associated with mortality in COVID-19 patients developing AKI [6] , future large meta-analyses may be suggested to explore the clinical impacts from different races in AKI mortality in COVID-19 patients.

Mortality rate of acute kidney injury in SARS, MERS, and COVID-19 infection: a systematic review and meta-analysis

Limitations of meta-analyses of studies with high heterogeneity

Updated guidance for trusted systematic reviews: a new edition of the Cochrane Handbook for Systematic Reviews of Interventions

COVID-19 in Racial and Ethnic Minority Groups, Inc.; c2020 [Updated

The association of race and COVID-19 mortality

AKI in hospitalized patients with and without COVID-19: a comparison study

ASN.2020040509

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Not applicable.Author's contributions JS drafted the manuscript. JS revised the manuscript critically for valuable intellectual content. JS approved the final manuscript.

There was no external funding regarding the letter.Availability of data and materials Not applicable.

Ethics approval and consent to participate Not applicable.

Not applicable.

The author has no conflict of interest to declare.Received: 28 July 2020 Accepted: 12 August 2020