Time Trend in Mortality and Attack rate of Nosocomial Infection by specific pathogens :surveillence data between 1994-2003 in SKH Hospital ,Taiwan
Date Issued
2005
Date
2005
Author(s)
Shen, Shu-Hui
DOI
en-US
Abstract
Objective We aimed to (1) assess time trend in attack rate, case-fatality rate, and mortality rate; (2) assess whether time trend vary multiple episodes, infection site , and pathogen; and to evaluate the interval between admission and onset of infection by pathogen
Methods Data on surveillance of nosocomial infection in SKMH was available electronically. We collected information on discharged patients, episodes of nosocomial Infections, and deaths between 1994 and 2003. After excluding 19,271 deliveries in the contemporaneous period, a total of 282,898 discharged patients were included in the following analysis. Of these patients, we identified 5330 patients with 8885 episodes of NI during 10-year period. After linkage with Taiwan National Mortality Registry, 1,711 deaths were ascertained, including 965 in-hospital deaths and 746 critical against advice discharge (AAD) deaths. Among death cases, 1,495 deaths (87.4%) died within 30 days after onset of NIs. We used a decomposition method to divide mortality related to NI into attack rate and case-fatality rate and assess time trend for these three rates. Time-series Poisson regression model was used to assess the change of three rate after controlling for other significant factors. The comparison of interval between admission and onset of infection between the USA and Taiwan was also made.
Results The overall time trend in attack rate has declined by 6%, decreasing from 3.30% in 1994 to 3.14 in 2003. However, the overall case-fatality rate was elevated by 55%, increasing from 13.96% in 1994 to 21.6% in 2003. Both yielded 46% increase in mortality rate attributed to NI, from 0.46% in 1994 to 0.67% in 2003.pathogens has declined from 1996 but rebounded since 2000. Episodes without culture had a slight increase since 1996. For case-fatality, the majority of pathogens showed an increasing trend. Only coagulase-negative Staphylococcus s and K pneumoniae showed a decreasing trend.
The finding form attack rate together with case-fatality gives the results of mortality rate with an increasing trend for most pathogens. Only coagulase-negative Staphylococcus showed a decreasing trend. The mortality trend for P. aeruginosa, K.pneumoniae, and E. cloacae was fairly constant. For multiple pathogens, time trend in mortality trend was pursuant to that in attack rate with declining from the year of 1996 and resurged from the year of 2000.
By using time-series Poisson regression analysis, after controlling for gender, age, frequency of admission, length of stays, and infection site, an increase (per week) in attack rate was 0.04% for fungus, 0.001% for S.aureus, 0.1% for E.coli, 0.047% for Acinetobacter spp, 0.037% for Enterococcus, and 0.33% for Enterobacter spp. The remaining pathogens showed a decline trend including Pseudomonas aeruginosa , coagulase-negative Staphylococcus, and E.coloacae. Episodes with multiple pathogens has declined from 1996 but rebounded since 2000. The average interval between admission and onset of infection in our study was longer that that in the USA. This is particularly seen for S.aureus, Coagulase-nagative Staphylococcus, fungus, and E.coli.
Conclusions Nosocomial infection with time trend decomposed in to attack rate, case-fatality rate and mortality using data from a large medical center varied with age, pathogen and site of infection. Such heterogeneity of time trend in attack rate and case-fatality rate may imply different measures for control nosocomial infection and need to be clarified in future research.
Subjects
院內感染
侵襲率
致死率
死亡率
布瓦松迴歸
nosocomial infection
attack rate
case-fatality rate
mortality
Poisson regression
Type
thesis