Clinical features, risk factors, and clinical burden of acute kidney injury in older adults

<b><i>Background:</i></b> Few epidemiologic studies on acute kidney injury (AKI) have focused on the older adult population. This study investigated the clinical features, risk factors, and clinical burden in this population. <b><i>Methods:</i></b> A retrospective observational study was performed with the clinical data of inpatients at Guangdong Geriatrics Institute from 1 August 2012, to 31 December 2016. AKI was classified into community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI), and the risk factors for AKI were ranked by weight. The relationships between AKI and adverse outcomes during hospitalization were analyzed using univariate and multivariate logistic regression. <b><i>Results:</i></b> In total, 6126 patients were enrolled, and 1704 patients developed AKI (27.8%): 6.3% had CA-AKI, and 21.5% had HA-AKI. In total, 1425 (23.3%), 202 (3.3%), and 77 (1.3%) patients had stage 1, 2 and 3 AKI, respectively. Age, dementia, moderate/severe renal disease, moderate/severe liver disease, metastatic solid tumor, female sex, congestive heart failure, chronic pulmonary disease, diabetes mellitus with chronic complications, non-metastatic tumor and lymphoma were independent risk factors for HA-AKI. The first five were also independent risk factors for CA-AKI. After multiple adjustment, AKI was associated with intensive care admission (CA-AKI: OR 5.688, 95% CI 3.122–10.361; HA-AKI: OR 4.704, 95% CI 3.023–7.298) and in-hospital mortality (CA-AKI: OR 5.073, 95% CI 2.447–10.517; HA-AKI: OR 13.198, 95% CI 8.133–21.419). <b><i>Conclusion:</i></b> AKI occurs in &gt;25% of older adults in the geriatric ward. In addition to traditional risk factors, dementia and tumors were risk factors for AKI in older adults. AKI is closely related to a poor prognosis.