Socioeconomic Influences on the Outcomes of Dialysis-Requiring Acute Kidney Injury in Brazil

INTRODUCTION: Although research suggests that socioeconomic deprivation is linked to a higher incidence of acute kidney injury (AKI) and worse outcomes in high-income countries, there is limited knowledge about these epidemiologic factors in developing countries. In addition, the impact of medical institution administration (private versus public) on AKI outcomes remains to be determined. METHODS: We studied 15,186 pediatric and adult patients with dialysis-requiring AKI (AKI-D) admitted to private and public hospitals in Rio de Janeiro, Brazil. According to Brazil's demographic census, socioeconomic indicators were derived from patient zip codes. Propensity score matching analysis and a mixed-effect Cox regression were used to assess the impact of socioeconomic indicators and hospital governance on patient survival. RESULTS: Crude mortality rates were higher in private hospitals than in public hospitals (71.8% vs. 59.5%, P < 0.001) and were associated with significant differences in age (75 years, interquartile range [IQR]: 61–83 vs. 53 years, IQR: 31–66), baseline renal function (prevalence of chronic kidney disease [CKD]: 33.2% vs. 23%, P < 0.001), comorbidities (Charlson score: 2.03 ± 0.87 vs. 1.72 ± 0.75, P < 0.001), and severity of presentation (mechanical ventilation: 76.5% vs. 58% and vasopressors: 72.8% vs. 50.5%, P < 0.001). After adjustments and propensity score matching, we found no effect of different hospital administrations or socioeconomic factors on mortality. Baseline characteristics and the severity of presentation primarily influenced AKI-D prognosis. CONCLUSIONS: Despite significant racial and socioeconomic differences in hospital governance, these indicators had no independent influence on mortality. Future epidemiologic studies should investigate these relevant assumptions to allow healthcare systems to manage this severe syndrome promptly.