The authors reply

Abstract

We thank Jamme and Geri for their comments.1Jamme M. Geri G. Time-dependent effect, immortal bias, and competing risk: 3 components that should be handled to assess the impact of covariates on occurrence of acute kidney injury.Kidney Int. 2020; 98: 1348Abstract Full Text Full Text PDF Scopus (2) Google Scholar When we first embarked on this study in mid-April 2020, the data on acute kidney injury (AKI) among patients hospitalized with coronavirus disease 2019 in the United States were sparse.2Hirsch J.S. Ng J.H. Ross D.W. et al.Acute kidney injury in patients hospitalized with COVID-19.Kidney Int. 2020; 98: 209-218Abstract Full Text Full Text PDF PubMed Scopus (453) Google Scholar Thus, our primary research question was to (i) determine the rates of AKI among these patients, and (ii) investigate the effects of potential explanatory variables on the occurrence of AKI.2Hirsch J.S. Ng J.H. Ross D.W. et al.Acute kidney injury in patients hospitalized with COVID-19.Kidney Int. 2020; 98: 209-218Abstract Full Text Full Text PDF PubMed Scopus (453) Google Scholar The goal was not to determine time-to-AKI, nor to make causal inferences about how mechanical ventilation causes AKI. Therefore, we continue to believe that logistic regression was the appropriate method to specifically answer our research question as opposed to performing a Cox regression analysis. Certainly, if the research question was to determine the instantaneous risk of AKI, then a Cox regression model with consideration of time-varying covariates, immortal bias, and competing risk would be important, as pointed out by Jamme and Geri.1Jamme M. Geri G. Time-dependent effect, immortal bias, and competing risk: 3 components that should be handled to assess the impact of covariates on occurrence of acute kidney injury.Kidney Int. 2020; 98: 1348Abstract Full Text Full Text PDF Scopus (2) Google Scholar KDJ servers as a consultant for Astex Pharmaceuticals and Natera. All the other authors declared no competing interests. Time-dependent effect, immortal bias, and competing risk: 3 components that should be handled to assess the impact of covariates on occurrence of acute kidney injuryKidney InternationalVol. 98Issue 5PreviewWe read with great interest the study from Hirsch et al. in the July 2020 issue of Kidney International.1 In that study, the authors aimed to identify risk factors of acute kidney injury (AKI) in patients admitted for coronavirus disease 2019. They compared characteristics of 5449 patients according to AKI occurrence and performed multivariable logistic regression to adjust for covariates. The authors have identified 2 risk factors occurring during the hospital stay: the need for mechanical ventilation (odds ratio = 31.6 [25.8–38.6] in univariate analysis and odds ratio = 10.7 [6.81–16.7] in multivariable analysis) and vasopressor medication (odds ratio = 31.4 [25.6–38.4] in univariate analysis and odds ratio = 4.5 [2.9–7.1] in multivariable analysis). Full-Text PDF Acute kidney injury in patients hospitalized with COVID-19Kidney InternationalVol. 98Issue 1PreviewThe rate of acute kidney injury (AKI) associated with patients hospitalized with Covid-19, and associated outcomes are not well understood. This study describes the presentation, risk factors and outcomes of AKI in patients hospitalized with Covid-19. We reviewed the health records for all patients hospitalized with Covid-19 between March 1, and April 5, 2020, at 13 academic and community hospitals in metropolitan New York. Patients younger than 18 years of age, with end stage kidney disease or with a kidney transplant were excluded. Full-Text PDF