Clinical Characteristics and Outcomes of Community-Acquired versus Hospital-Acquired Acute Kidney Injury: A Meta-Analysis

Background: The different clinical characteristics of community-acquired acute kidney injury (CA-AKI) versus hospital-acquired AKI (HA-AKI) have remained inconclusive, and thus, a meta-analysis was conducted to summarize and quantify the clinical significance distinguishing the 2 types of AKI. Methods: We identified observational studies reporting the clinical characteristics and prognosis of HA-AKI and CA-AKI. ORs and mean differences (MDs) were extracted for each outcome and the results aggregated. The primary outcome was defined as the mortality rate; renal recovery, oliguria incidence, dialysis, intensive care unit (ICU) requirement, and length of hospital stay were secondary outcomes. Results: Fifteen eligible studies involving 46,157 patients (22,791 CA-AKI patients and 23,366 HA-AKI patients) were included. Mortality was significantly lower in CA-AKI than in HA-AKI patients, with an OR of 0.43 (95% CI 0.35-0.53). The incidence of oliguria and need for ICU were also lower in CA-AKI patients (OR 0.58, 95% CI 0.38-0.88; OR 0.24, 95% CI 0.14-0.40, respectively). CA-AKI patients had a shorter hospital stay (MD -9.42, 95% CI -13.73 to -5.12). The renal recovery rate and dialysis need between CA- and HA-AKI were similar (OR 1.27, 95% CI 0.53-3.02; OR 1.05, 95% CI 0.82-1.34, respectively). Conclusions: CA-AKI showed better clinical manifestations with a lower incidence of oliguria, reduced risk of ICU treatment, and shorter hospital stay. Mortality associated with CA-AKI was lower compared with HA-AKI, indicating a better prognosis. The rate of renal recovery and need for dialysis showed no significant difference between the 2 groups.