Background: Acute kidney injury (AKI) is a clinical syndrome affecting almost one fifth of hospitalized patients, as well as more than half of the patients who are admitted to the intensive care unit (ICU). Stratifying AKI patients into groups based on severity and duration would facilitate more targeted efforts for treating AKI. Methods: In a retrospective, multicenter and longitudinal cohort study of 935,679 patients who were admitted between 2012 and 2020 to health centers included in OneFlorida+ Network, we analyzed the impact of AKI trajectories which are rapidly reversed AKI, persistent AKI with renal recovery, and persistent AKI without renal recovery on patients' clinical outcomes, including hospital, 30-day, 1-year, and 3-year mortality, kidney replacement therapy, new chronic kidney disease (CKD) within 90 days or 1-year of discharge, CKD progression within 1-year of discharge, resource utilization, hospital disposition, and major complications during hospitalization. As analytical approaches, Kaplan-Meier estimators and survival curves, Cox proportional-hazards regression model, logistic regression model, Kruskal-Wallis test, analysis of variance, chi-square, Fisher's exact test were used. Results: Among 2,187,254 encounters, 14% had AKI, of which 63%, 21%, and 16% had Stage 1, 2, and 3, respectively, as the worst AKI stage. Fraction of patients with persistent AKI was 31%. Patients with AKI had worse clinical outcomes and increased resource utilization compared to patients without the condition. One-year mortality was 5 times greater for patients with persistent AKI compared to those without AKI. Conclusions: Persistent AKI was associated with prolonged hospitalization, increased ICU admission and mortality compared to the other groups. This may emphasize the critical need for devising strategies targeting effective management of AKI and prevention of persisting AKI.

翻译：背景：急性肾损伤（AKI）是一种临床综合征，影响近五分之一住院患者及超过半数重症监护病房（ICU）入院患者。根据严重程度和持续时间将AKI患者分层，有助于开展更具针对性的治疗。方法：本研究纳入OneFlorida+协作网中2012年至2020年间收治的935,679例患者，通过回顾性多中心纵向队列研究，分析不同AKI轨迹（快速逆转型AKI、伴肾功能恢复的持续性AKI、无肾功能恢复的持续性AKI）对临床结局的影响，包括住院死亡率、30天/1年/3年死亡率、肾脏替代治疗、出院后90天或1年内新发慢性肾脏病（CKD）、出院后1年内CKD进展、医疗资源利用、出院去向及住院期间主要并发症。统计分析采用Kaplan-Meier估计量与生存曲线、Cox比例风险回归模型、Logistic回归模型、Kruskal-Wallis检验、方差分析、卡方检验及Fisher精确检验。结果：在2,187,254次住院记录中，14%发生AKI，其中最高AKI分期为1期、2期和3期的比例分别为63%、21%和16%。持续性AKI患者占31%。与非AKI患者相比，AKI患者临床结局更差且医疗资源消耗增加。持续性AKI组1年死亡率是非AKI组的5倍。结论：相较于其他组别，持续性AKI与住院时间延长、ICU入住率及死亡率升高显著相关。这提示急需制定针对AKI有效管理及预防持续性AKI的策略。