Abstract
Background and Objectives: Acute kidney injury (AKI) is a common complication of COVID-19 and is associated with increased short-term mortality. However, long-term kidney outcomes among survivors remain incompletely characterized. Materials and Methods: We conducted a cohort study of hospitalized COVID-19 patients at a tertiary care university hospital, classifying them during admission according to the KDIGO AKI criteria. Survivors underwent follow-up assessment approximately 1.5–2 years post-discharge, which included laboratory evaluations and a structured questionnaire. This questionnaire collected patient-reported outcomes regarding post-discharge health worsening and any new medical diagnoses during the follow-up period. The primary outcome was a composite of all-cause mortality or kidney function decline (defined as an eGFR < 60 mL/min/1.73 m² and a ≥25% decrease from discharge). Associated factors were identified using modified Poisson regression models. Results: A total of 180 patients were included (60 with AKI and 120 without). Patients with AKI were older, had more comorbidities, and experienced more severe COVID-19. At a median follow-up of 1.65 years, 4 patients with AKI had died and one required kidney transplantation. Patients in AKI group more frequently reported worsening overall health and newly diagnosed conditions (both p < 0.05). The composite outcome occurred more frequently in the AKI group including lower follow-up eGFR and greater eGFR decline. In multivariable analysis, AKI remained independently associated with the primary outcome (adjusted RR 7.92, 95% CI 2.41–25.98; p < 0.001). Conclusions: Among COVID-19 survivors, AKI is associated with worsening patient-reported health status and adverse long-term outcomes, including kidney function decline and death. These findings support the need for structured post-discharge kidney monitoring in this high-risk population.