Gallego Aristizabal Paola Andrea, Lujan Chavarría Tania Paola, Rodelo-Ceballos Joaquín, Botero Bolívar Sara, Vergara Hernández Sara Isabel, Rocha Giraldo Isabella, Marcillo Calderón Cristian Fernando, Londoño Giraldo Ana María, Rincon Acosta Federico, Sanchez Carmona María Paula, Salazar Ospina Paula Andrea, Jaimes Fabián
Department of Internal Medicine, Faculty of Medicine, Universidad de Antioquia, Carrera 73 # 53-93, Medellín, Colombia.
Hospital Universitario San Vicente Fundación, Medellín, Colombia.
J Nephrol. 2025 Sep 8. doi: 10.1007/s40620-025-02415-1.
Acute kidney injury (AKI) is a common complication in patients affected by COVID-19 and has been strongly associated with increased mortality. However, its independent contribution remains debated. This study aimed to evaluate the independent association using a directed acyclic graph-based approach.
Retrospective, multicenter cohort study in Medellín, Colombia, from June 2020 to April 2022. AKI was defined according to KDIGO criteria. A directed acyclic graph was constructed to map the hypothesized causal relationship between AKI and mortality, integrating evidence from a comprehensive literature review and expert´s consensus. A Poisson regression model with robust variance was applied to estimate adjusted incidence rate ratios (IRRs) for mortality.
A total of 1722 patients were included, of whom 30.7% developed AKI. Mortality was higher among patients with AKI (58.1% vs. 19.6%). A directed acyclic graph was used to identify a minimal sufficient adjustment set for confounding control. After adjustment, the IRRs for in-hospital mortality were 1.25 (95% CI: 1.09-1.43) for stage 1, 1.62 (95% CI: 1.35-1.93) for stage 2, and 1.64 (95% CI: 1.46-1.85) for stage 3.
AKI is independently and significantly associated with an increased risk of mortality in COVID-19 patients. This study makes a novel contribution by applying directed acyclic graphs to enhance causal inference. Directed acyclic graphs provide a rigorous framework for identifying true confounders and avoiding inappropriate adjustment for mediators, thereby reducing bias and improving the validity of causal estimates. In clinical settings where randomized controlled trials are not feasible, the use of directed acyclic graphs represents a robust alternative for exploring causal relationships.
急性肾损伤（AKI）是新型冠状病毒肺炎（COVID-19）患者常见的并发症，且与死亡率增加密切相关。然而，其独立影响仍存在争议。本研究旨在使用基于有向无环图的方法评估其独立关联。
2020年6月至2022年4月在哥伦比亚麦德林进行的一项回顾性多中心队列研究。AKI根据改善全球肾脏病预后组织（KDIGO）标准定义。构建有向无环图以描绘AKI与死亡率之间的假定因果关系，整合来自全面文献综述和专家共识的证据。应用具有稳健方差的泊松回归模型估计死亡率的调整发病率比（IRR）。
共纳入1722例患者，其中30.7%发生AKI。AKI患者的死亡率更高（58.1%对19.6%）。使用有向无环图确定用于混杂控制的最小充分调整集。调整后，1期住院死亡率的IRR为1.25（95%置信区间：1.09 - 1.43），2期为1.62（95%置信区间：1.35 - 1.93），3期为1.64（95%置信区间：1.46 - 1.85）。
AKI与COVID-19患者死亡率增加独立且显著相关。本研究通过应用有向无环图加强因果推断做出了新贡献。有向无环图为识别真正的混杂因素和避免对中介因素进行不适当调整提供了一个严谨的框架，从而减少偏差并提高因果估计的有效性。在随机对照试验不可行的临床环境中，使用有向无环图是探索因果关系的有力替代方法。
