Factors associated with successful completion of outpatient parenteral antibiotic therapy in an area with a high prevalence of multidrug-resistant bacteria: 30-day hospital admission and mortality rates

<b>Synopsis</b> <b>Objectives:</b> To identify factors associated with hospital admission and mortality within the first 30 days after enrolment in an outpatient parenteral antimicrobial therapy (OPAT) program, also analysing adequacy of the treatment regimen and clinical outcomes. <b>Patients and methods:</b> This was a retrospective cohort study conducted between October 2016 and June 2017 in the state of São Paulo, Brazil. Variables related to hospital admission and mortality were subjected to bivariate analysis, and those with a <i>P</i>&lt;0.05 were subjected to multivariate analysis as risk factors. <b>Results:</b> We evaluated 276 patients, of whom 80.5% were ≥60 years of age and 69.9% had more than one comorbidity. Of the patients evaluated, 41.3% had pneumonia and 35.1% had a urinary tract infection. The most common etiological agent, isolated in 18 (31.6%) cases, was <i>Klebsiella pneumoniae</i>, and 13 (72,2%) strains were carbapenem resistant. The OPAT was in accordance with the culture results in 76.6% of the cases and with the institutional protocols in 76.4%. The majority (64.5%) of the patients were not admitted, and a cure or clinical improvement was achieved in 78.6%. Multivariate analysis showed that, within the first 30 days after enrolment, the absence of a physician office visit was a predictor of hospital admission (<i>P</i>&lt;0.001) and mortality (<i>P</i>=0.006). <b>Conclusions:</b> This study demonstrated the viability of OPAT in elderly patients with pulmonary or urinary tract infections in an area with a high prevalence of multidrug-resistant bacteria and that a post-discharge physician office visit is protective against hospital admission and mortality.

**研究概述**
### 研究目标：
识别门诊静脉抗菌治疗（outpatient parenteral antimicrobial therapy, OPAT）项目入组后30天内与住院及死亡相关的影响因素，同时分析治疗方案的适宜性与临床转归。
### 患者与方法：
本研究为回顾性队列研究，于2016年10月至2017年6月在巴西圣保罗州开展。针对与住院及死亡相关的变量进行双变量分析，将*P*<0.05的变量作为危险因素纳入多变量分析。
### 研究结果：
本研究共纳入276例患者，其中80.5%的患者年龄≥60岁，69.9%的患者合并至少2种基础疾病。入组患者中，41.3%罹患肺炎，35.1%患有尿路感染。最常见的病原菌为肺炎克雷伯菌（Klebsiella pneumoniae），共分离出18株（31.6%），其中72.2%的菌株对碳青霉烯类药物耐药。76.6%的病例的OPAT治疗方案符合病原学培养结果，76.4%的方案符合所在医疗机构的诊疗规范。多数患者（64.5%）未发生住院事件，78.6%的患者实现临床治愈或症状改善。多变量分析结果显示，入组后30天内未接受门诊医师随访是患者住院（*P*<0.001）及死亡（*P*=0.006）的独立预测因素。
### 研究结论：
本研究证实，在多重耐药菌流行率较高的地区，针对肺部或尿路感染的老年患者开展OPAT治疗具有可行性；出院后接受门诊医师随访可降低患者住院及死亡风险。