Hooton T M, Haley R W, Culver D H
Am J Epidemiol. 1980 May;111(5):556-73. doi: 10.1093/oxfordjournals.aje.a112934.
To compare validly the nosocomial infection rates (NIRs) in groups of patients studied from different time periods and/or different hospitals, one must control for the important factors that influence a patient's susceptibility to infection. The authors developed a method for assessing one component of nosocomial infection risk, based on patients' diagnoses and surgical procedures. This method classifies patients according to their risk of developing a nosocomial infection at each of four infection sites and at all four sites combined. Applying the method to data collected on 136,516 patients from 276 hospitals studied in the SENIC Project (Study on the Efficacy of Nosocomial Infection Control), the authors found that NIRs increased according to the predicted ranking of risk categories, even when the analyses were stratified individually by age, sex, hospital service and exposure to urinary catheterization or continuous ventilatory support. Depending on the site of infection, the rate increased as much as 100-fold from low-risk to high-risk categories. The data indicate that infection risk as assessed with this classification method will account for some of the variation in NIRs due to differences in patients' clinical conditions. Further analyses using multivariate techniques must be performed to explore in detail the relative importance of this risk classification in comparison with other risk factors and to determine which factors must be controlled in SENIC analyses.
为了有效地比较不同时间段和/或不同医院所研究患者群体的医院感染率（NIRs），必须控制影响患者感染易感性的重要因素。作者基于患者的诊断和手术操作开发了一种评估医院感染风险一个组成部分的方法。该方法根据患者在四个感染部位中每个部位以及四个部位综合起来发生医院感染的风险对患者进行分类。将该方法应用于在SENIC项目（医院感染控制效果研究）中对来自276家医院的136,516名患者收集的数据，作者发现即使按年龄、性别、医院科室以及是否接受导尿或持续通气支持分别进行分层分析，NIRs也会根据风险类别的预测排名而增加。根据感染部位的不同，从低风险类别到高风险类别，感染率增加高达100倍。数据表明，用这种分类方法评估的感染风险将解释由于患者临床状况差异导致的NIRs的部分变化。必须使用多变量技术进行进一步分析，以详细探讨这种风险分类与其他风险因素相比的相对重要性，并确定在SENIC分析中必须控制哪些因素。
