Antibiotic prophylaxis for surgical site infections as a risk factor for infection with Clostridium difficile

ObjectiveWe aimed to measure the association between 2013 guideline concordant prophylactic antibiotic use prior to surgery and infection with Clostridium difficile.DesignWe conducted a retrospective case-control study by selecting patients who underwent a surgical procedure between January 1, 2012 and December 31, 2013.SettingLarge urban community hospital.PatientsCases and controls were patients age 18+ years who underwent an eligible surgery (i.e., colorectal, neurosurgery, vascular/cardiac/thoracic, hysterectomy, abdominal/pelvic and orthopedic surgical procedures) within six months prior to infection diagnosis. Cases were diagnosed with C. difficile infection while controls were not.MethodsThe primary exposure was receiving (vs. not receiving) the recommended prophylactic antibiotic regimen, based on type and duration. Potential confounders included age, sex, length of hospital stay, comorbidities, type of surgery, and prior antibiotic use. Crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.ResultsWe enrolled 68 cases and 220 controls. The adjusted OR among surgical patients between developing C. difficile infection and not receiving the recommended prophylactic antibiotic regimen (usually receiving antimicrobial prophylaxis for more than 24 hours) was 6.7 (95% CI: 2.9–15.5). Independent risk factors for developing C. difficile infection included having severe comorbidities, receiving antibiotics within the previous 6 months, and undergoing orthopedic surgery.ConclusionsAdherence to the recommended prophylactic antibiotics among surgical patients likely reduces the probability of being case of C. difficile. Antibiotic stewardship should be a priority in strategies to decrease the morbidity, mortality, and costs associated with C. difficile infection.

研究目的：本研究旨在探讨符合2013年指南的术前预防性抗生素使用与艰难梭菌（Clostridium difficile）感染之间的关联。
研究设计：本研究采用回顾性病例对照研究设计，纳入2012年1月1日至2013年12月31日期间接受外科手术的患者。
研究地点：大型城市社区医院。
研究对象：病例组与对照组均为年龄≥18岁，且在感染诊断前6个月内接受了符合纳入标准的外科手术（包括结直肠手术、神经外科手术、血管/心脏/胸外科手术、子宫切除术、腹部/盆腔手术及骨科手术）的患者。其中，病例组为确诊艰难梭菌感染的患者，对照组未发生该感染。
研究方法：本研究的主要暴露因素为是否接受基于手术类型与疗程制定的推荐预防性抗生素给药方案。潜在混杂因素包括年龄、性别、住院时长、合并症、手术类型及既往抗生素使用情况。采用logistic回归模型计算粗比值比（odds ratio）、校正后比值比（adjusted odds ratio, OR）及95%置信区间（confidence interval, CI）。
研究结果：本研究共纳入68例病例及220例对照。外科患者中，未遵循推荐预防性抗生素给药方案（通常指抗菌药物预防疗程超过24小时）者发生艰难梭菌感染的校正比值比为6.7（95%置信区间：2.9–15.5）。艰难梭菌感染的独立危险因素包括合并重症疾病、近6个月内接受抗生素治疗及接受骨科手术。
研究结论：外科患者遵循推荐的预防性抗生素使用方案，或可降低罹患艰难梭菌感染的风险。抗生素管理（Antibiotic stewardship）应作为降低艰难梭菌感染相关发病率、死亡率及医疗成本的策略中的优先事项。