Abstract: Background　In recent years，the rate of Clostridium difficile infection（CDI） has increased rapidly，and the number of serious infections has increased dramatically，especially in the elderly over 60 years old.However，there are few studies on CDI in the elderly in China.Objective　To analyze the associated factors of in-hospital CDI in elderly inpatients with pulmonary infection，to improve the levels of clinical treatment，prevention and control of this disease.Methods　Participants were recruited from Beijing Friendship Hospital，Capital Medical University，from March 2013 to March 2018，including 70 elderly inpatients with pulmonary infection and in-hospital CDI （CDI group），and other sex- and age-matched 70 pulmonary infection inpatients without in-hospital CDI （control group，no CDI occurred during hospitalization）．Clinical data（basic personal data，antibiotic use and other related data） of both groups were retrospectively collected.Influencing factors of in-hospital CDI were analyzed by multivariate Logistic regression analysis.Results　The rates of having at least 3 underlying diseases，in-hospital nutrition support pattern，Barthel index，use of the 3rd-/4th-generation cephalosporins，use of carbapenems，use of antibiotics for at least 1 month，undergoing surgery with general anesthesia in the past 3 months，use of hormones or immunosuppressive agents，use of proton pump inhibitors，and hypoproteinemia as well mean level of CRP differed significantly between the groups（P<0.05）．Nutrition support pattern 〔nasal feeding：OR=4.528，95%CI（1.079，19.004）〕，Barthel index 〔≤40：OR=13.812，95%CI（1.153，165.500）〕，undergoing surgery with general anesthesia in the past 3 months 〔OR=8.358，95%CI（1.566，44.611）〕，use of carbapenems〔OR=5.496，95%CI（1.073，28.163）〕，use of hormones or immunosuppressive agents 〔OR=13.128，95%CI（2.291，75.242）〕，use of proton pump inhibitors 〔OR=4.980，95%CI（1.112，22.305）〕，and hypoalbuminemia 〔OR=5.351，95%CI（1.488，19.246）〕 were associated with increased risk of in-hospital CDI in elderly inpatients with pulmonary infection（P<0.05）．Conclusion　Risk factors of in-hospital CDI in elderly inpatients with pulmonary infection were nasal feeding，Barthel index ≤ 40，undergoing surgery with general anesthesia in the past 3 months，use of carbapenems，use of hormones or immunosuppressive agents，use of proton pump inhibitors and hypoalbuminemia.More attention should be paid to these patients and individualized treatment should be delivered.

Key words: Lung diseases, Aged, Clostridium difficile, Root cause analysis, Inpatients

摘要： 背景　近年来，难辨梭菌感染（CDI）发生率迅速上升，严重感染者急剧增加，尤其是60岁以上的老年人。而我国有关老年人CDI的研究较少。目的　探究老年肺部感染住院患者发生CDI的影响因素，以提高临床治疗与防控能力。方法　收集2013年3月—2018年3月于首都医科大学附属北京友谊医院住院的70例发生CDI的老年肺部感染住院患者（CDI组）的临床资料，另收集同期于本院住院的70例老年肺部感染住院患者（对照组，住院期间未发生CDI）的临床资料（性别、年龄与CDI组相匹配）。回顾性收集两组患者的基本资料、抗生素使用情况及其他相关资料，并采用多因素Logistic回归分析研究老年肺部感染住院患者发生CDI的影响因素。结果　CDI组与对照组合并基础疾病≥3种所占比例、入院后营养方式、Barthel指数、第三/四代头孢使用率、碳青霉烯类药物使用率、抗生素使用时间≥1个月所占比例、3个月内曾行全麻手术所占比例、激素或免疫抑制剂应用率、质子泵抑制剂应用率、C反应蛋白（CRP）、低清蛋白血症发生率比较，差异有统计学意义（P<0.05）。营养方式〔鼻饲营养：OR=4.528，95%CI（1.079，19.004）〕、Barthel指数〔≤40分：OR=13.812，95%CI（1.153，165.500）〕、3个月内曾行全麻手术〔OR=8.358，95%CI（1.566，44.611）〕、使用碳青霉烯类药物〔OR=5.496，95%CI（1.073，28.163）〕、应用激素或免疫抑制剂〔OR=13.128，95%CI（2.291，75.242）〕、应用质子泵抑制剂〔OR=4.980，95%CI（1.112，22.305）〕、低清蛋白血症〔OR=5.351，95%CI（1.488，19.246）〕是老年肺部感染住院患者发生CDI的影响因素（P<0.05）。结论　老年肺部感染住院患者发生CDI的影响因素为鼻饲营养、Barthel指数≤40分、3个月内曾行全麻手术、使用碳青霉烯类药物、应用激素或免疫抑制剂、应用质子泵抑制剂、低清蛋白血症，临床应提高对该类患者的关注度，制定个性化的治疗。

关键词: 肺疾病, 老年人, 难辨梭菌, 影响因素分析, 住院病人