Walberg Mette, Frøslie Kathrine Frey, Røislien Jo
Microbiology Section, Laboratory Centre, Asker and Baerum Hospital, Rud, Norway.
Infect Control Hosp Epidemiol. 2008 Jul;29(7):635-41. doi: 10.1086/589332.
To implement a system for monitoring of rare events based on statistical process control charts.
Statistical process control plotting by g chart of clinical microbiology laboratory data.
Primary and secondary care Norwegian hospital with a 9-bed intensive care unit.
During the winter of 2001-2002 in Norway, there was a national monoclonal nosocomial outbreak of Pseudomonas aeruginosa infection mainly affecting patients in intensive care units. In the present work, we demonstrate how the use of SPC at one of the affected hospitals would have detected this outbreak several weeks before the alert from the Norwegian National Public Health Institute (NIPH). By plotting the monthly incidence rate of P. aeruginosa infection (with a c chart), we found that the hospital would have been alerted in February; by plotting the number of days between events (with a g chart), we found that the hospital would have detected a process already out of control in early January 2002. Not until 9 weeks later (ie, mid-March) did the NIPH declare the P. aeruginosa outbreak to be national, and a commercially produced mouth swab contaminated during the manufacturing process was found to be the source.
The plotting of rare events, such as an outbreak of nosocomial infection, with a g chart may be used for early detection of a process out of control.
实施一个基于统计过程控制图的罕见事件监测系统。
通过g图对临床微生物实验室数据进行统计过程控制绘图。
挪威一家拥有9张床位重症监护病房的一级和二级护理医院。
在2001 - 2002年冬季的挪威，全国范围内发生了一次铜绿假单胞菌感染的单克隆医院内暴发，主要影响重症监护病房的患者。在本研究中，我们展示了在其中一家受影响医院使用统计过程控制（SPC）如何能在挪威国家公共卫生研究所（NIPH）发出警报前数周就检测到这次暴发。通过绘制铜绿假单胞菌感染的月发病率（使用c图），我们发现该医院会在2月收到警报；通过绘制事件之间的天数（使用g图），我们发现该医院在2002年1月初就会检测到一个已失控的过程。直到9周后（即3月中旬），NIPH才宣布铜绿假单胞菌暴发为全国性事件，并且发现生产过程中被污染的一种商用口拭子是源头。
使用g图绘制诸如医院感染暴发等罕见事件，可用于早期检测失控过程。
