Emori T G, Edwards J R, Culver D H, Sartor C, Stroud L A, Gaunt E E, Horan T C, Gaynes R P
Hospital Infections Program, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
Infect Control Hosp Epidemiol. 1998 May;19(5):308-16. doi: 10.1086/647820.
To assess the accuracy of nosocomial infections data reported on patients in the intensive-care unit by nine hospitals participating in the National Nosocomial Infections Surveillance (NNIS) System.
A pilot study was done in two phases to review the charts of selected intensive-care-unit patients who had nosocomial infections reported to the NNIS System. The charts of selected high- and low-risk patients in the same cohort who had no infections reported to the NNIS System also were included. In phase I, trained data collectors reviewed a sample of charts for nosocomial infections. Retrospectively detected infections that matched with previously reported infections were deemed to be true infections. In phase II, two Centers for Disease Control and Prevention (CDC) epidemiologists reexamined a sample of charts for which a discrepancy existed. Each sampled infection either was confirmed or disallowed by the epidemiologists. Confirmed infections also were deemed to be true infections. True infections from both phases were used to estimate the accuracy of reported NNIS data by calculating the predictive value positive, sensitivity, and specificity at each major infection site and the "other sites."
The data collectors examined a total of 1,136 patients' charts in phase I. Among these charts were 611 infections that the study hospitals had reported to the CDC. The data collectors retrospectively matched 474 (78%) of the prospectively identified infections, but also detected 790 infections that were not reported prospectively. Phase II focused on the discrepant infections: the 137 infections that were identified prospectively and reported but not detected retrospectively, and the 790 infections that were detected retrospectively but not reported previously. The CDC epidemiologists examined a sample of 113 of the discrepant reported infections and 369 of the discrepant detected infections, and estimated that 37% of all discrepant reported infections and 43% of all discrepant detected infections were true infections. The predictive value positive for reported bloodstream infections, pneumonia, surgical-site infection, urinary tract infection, and other sites was 87%, 89%, 72%, 92%, and 80%, respectively; the sensitivity was 85%, 68%, 67%, 59%, and 30%, respectively; and the specificity was 98.3%, 97.8%, 97.7%, 98.7%, and 98.6%, respectively.
When the NNIS hospitals in the study reported a nosocomial infection, the infection most likely was a true infection, and they infrequently reported conditions that were not infections. The hospitals also identified and reported most of the nosocomial infections that occurred in the patients they monitored, but accuracy varied by infection site. Primary bloodstream infection was the most accurately identified and reported site. Measures that will be taken to improve the quality of the infection data reported to the NNIS System include reviewing the criteria for definitions of infections and other data fields, enhancing communication between the CDC and NNIS hospitals, and improving the training of surveillance personnel in NNIS hospitals.
评估参与国家医院感染监测（NNIS）系统的9家医院上报的重症监护病房患者医院感染数据的准确性。
分两个阶段进行一项试点研究，以审查向NNIS系统上报医院感染的特定重症监护病房患者的病历。同一队列中未向NNIS系统上报感染的选定高风险和低风险患者的病历也被纳入。在第一阶段，经过培训的数据收集人员审查医院感染病历样本。与先前上报感染相匹配的回顾性检测到的感染被视为真正的感染。在第二阶段，两名疾病控制与预防中心（CDC）的流行病学家重新审查存在差异的病历样本。每位抽样感染由流行病学家确认或排除。确认的感染也被视为真正的感染。通过计算每个主要感染部位和“其他部位”的阳性预测值、敏感性和特异性，将两个阶段的真正感染用于估计上报的NNIS数据的准确性。
数据收集人员在第一阶段共审查了1136例患者的病历。在这些病历中有611例感染，研究医院已向CDC上报。数据收集人员回顾性匹配了前瞻性确定感染中的474例（78%），但也检测到790例未前瞻性上报的感染。第二阶段聚焦于差异感染：前瞻性确定并上报但回顾性未检测到的137例感染，以及回顾性检测到但先前未上报的790例感染。CDC流行病学家审查了113例差异上报感染和369例差异检测到感染的样本，并估计所有差异上报感染中的37%和所有差异检测到感染中的43%为真正的感染。上报的血流感染、肺炎、手术部位感染、尿路感染和其他部位的阳性预测值分别为87%、89%、72%、92%和80%；敏感性分别为85%、68%、67%、59%和30%；特异性分别为98.3%、97.8%、97.7%、98.7%和98.6%。
当研究中的NNIS医院上报医院感染时，该感染很可能是真正的感染，且他们很少上报非感染情况。医院也识别并上报了他们所监测患者中发生的大多数医院感染，但准确性因感染部位而异。原发性血流感染是识别和上报最准确的部位。为提高向NNIS系统上报的感染数据质量将采取的措施包括审查感染及其他数据字段定义的标准、加强CDC与NNIS医院之间的沟通，以及改善NNIS医院监测人员的培训。
