Community-Acquired Acute Kidney Injury: A Nationwide Survey in China

Abstract

Background: This study aimed to describe the burden of community-acquired acute kidney injury (AKI) in China based on a nationwide survey about AKI.

Study design: Cross-sectional and retrospective study.

Setting & participants: A national sample of 2,223,230 hospitalized adult patients from 44 academic/local hospitals in Mainland China was used. AKI was defined according to the 2012 KDIGO AKI creatinine criteria or an increase or decrease in serum creatinine level of 50% during the hospital stay. Community-acquired AKI was identified when a patient had AKI that could be defined at hospital admission.

Predictors: The rate, cause, recognition, and treatment of community-acquired AKI were stratified according to hospital type, latitude, and economic development of the regions in which the patients were admitted.

Outcomes: All-cause in-hospital mortality and recovery of kidney function at hospital discharge.

Results: 4,136 patients with community-acquired AKI were identified during the 2 single-month snapshots (January 2013 and July 2013). Of these, 2,020 (48.8%) had cases related to decreased kidney perfusion; 1,111 (26.9%), to intrinsic kidney disease; and 499 (12.1%), to urinary tract obstruction. In the north versus the south, more patients were exposed to nephrotoxins or had urinary tract obstructions. 536 (13.0%) patients with community-acquired AKI had indications for renal replacement therapy (RRT), but only 347 (64.7%) of them received RRT. Rates of timely diagnosis and appropriate use of RRT were higher in regions with higher per capita gross domestic product. All-cause in-hospital mortality was 7.3% (295 of 4,068). Delayed AKI recognition and being located in northern China were independent risk factors for in-hospital mortality, and referral to nephrology providers was an independent protective factor.

Limitations: Possible misclassification of AKI and community-acquired AKI due to nonstandard definitions and missing data for serum creatinine.

Conclusions: The features of community-acquired AKI varied substantially in different regions of China and were closely linked to the environment, economy, and medical resources.

Keywords: Acute kidney injury (AKI); China; community-acquired AKI; decreased kidney perfusion; etiology; health disparities; incidence; mortality; nationwide survey; per capita gross domestic product; regional variation; renal replacement therapy (RRT); serum creatinine.