[Surgical site infection following abdominal surgery in China: a multicenter cross-sectional study]

To determine the incidence of surgical site infection (SSI) after abdominal surgery and to further evaluate the related risk factors of SSI in China.The multicenter cross-sectional study collected clinical data of all adult patients who underwent abdominal surgery from May 1, 2018 to May 31, 2018 in 30 domestic hospitals, including basic information, perioperative parameters, and incisional microbial culture results. The primary outcome was the incidence of SSI within postoperative 30 days. SSI was classified into superficial incision infection, deep incision infection, and organ/gap infection according to the US Centers for Disease Control and Prevention (CDC) criteria. The secondary outcome variables were ICU stay, postoperative hospital stay, total hospital stay, 30-day mortality and treatment costs. Multivariate logistic regression was used to analyze the risk factors of SSI.A total of 1666 patients were enrolled in the study, including 263 cases of East War Zone Hospital of PLA, 140 cases of Affiliated Hospital of Qingdao University, 108 cases of The First Affiliated Hospital of Nanchang University, 87 cases of Central War Zone Hospital of PLA, 77 cases of West China Hospital, 74 cases of Guangdong General Hospital, 71 cases of Chenzhou First People's Hospital, 71 cases of Zigong First People's Hospital, 64 cases of Zhangjiagang First People's Hospital, 56 cases of Nanyang City Central Hospital, 56 cases of Lanzhou General Hospital of Lanzhou Military Command, 56 cases of Shandong Provincial Hospital, 52 cases of Shangqiu First People's Hospital, 52 cases of People's Hospital of Xinjiang Uygur Autonomous Region, 48 cases of The Second Xiangya Hospital of Central South University, 48 cases of Chinese PLA General Hospital, 44 cases of Affiliated Hospital of Xuzhou Medical University, 38 cases of Hunan Province People's Hospital, 36 cases of Dongguan Kanghua Hospital, 30 cases of Shaoxing Central Hospital, 30 cases of Northern Jiangsu People's Hospital, 29 vases of The First Affiliated Hospital of Zhengzhou University, 27 cases of General Hospital of Tianjin Medical University, 22 cases of Zigong Fourth People's Hospital, 21 cases of The Second Hospital of University of South China, 18 cases of Tongji Hospital, 15 cases of Nanchong Central Hospital, 12 cases of The 901th Hospital of PLA, 11 cases of Hunan Cancer Hospital, 10 cases of Lanzhou University Second Hospital. There were 1019 males and 647 females with mean age of (56.5±15.3) years old. SSI occurred in 80 patients (4.8%) after operation, including 39 cases of superficial incision infection, 16 cases of deep incision infection, and 25 cases of organ/interstitial infection. Escherichia coli was the main pathogen of SSI, and the positive rate was 32.5% (26/80). Compared with patients without SSI, those with SSI had significantly higher ICU occupancy rate [38.8%(31/80) vs. 13.9%(220/1586), P0.001], postoperative hospital stay (median 17 days vs. 7 days, P0.001) and total hospital stay (median 22 days vs. 13 days, P0.001), and significantly higher cost of treatment (median 75 000 yuan vs. 44 000 yuan, P0.001). Multivariate analysis showed that male rise(OR=2.110, 95%CI:1.175-3.791, P=0.012), preoperative blood glucose level rise(OR=1.100, 95%CI: 1.012-1.197, P=0.026), operative time (OR=1.006, 95%CI:1.003-1.009, P0.001) and surgical incision grade (clean-contaminated incision:OR=10.207, 95%CI:1.369-76.120, P=0.023; contaminated incision: OR=10.617, 95%CI:1.298-86.865, P=0.028; infection incision: OR=20.173, 95%CI:1.768-230.121, P=0.016) were risk factors for SSI; and laparoscopic surgery (OR=0.348, 95%CI:0.192-0.631, P=0.001) and mechanical bowel preparation(OR=0.441,95%CI:0.221-0.879, P=0.020) were protective factors for SSI.The incidence of postoperative SSI in patients with abdominal surgery in China is 4.8%. SSI can significantly increase the medical burden of patients. Preoperative control of blood glucose and mechanical bowel preparation are important measures to prevent SSI.