陳秀熙臺灣大學：預防醫學研究所沈淑惠Shen, Shu-HuiShu-HuiShen2007-11-282018-06-292007-11-282018-06-292005http://ntur.lib.ntu.edu.tw//handle/246246/59220研究目的 本研究欲分析院內感染之侵襲率、致死率及相關死亡率之時間趨勢，並進一步分析此時間趨勢是否會隨多重感染發生型態、感染部門及感染菌種的不同而有差異。最後，我們希望評估不同感染菌種對住院日到感染發病日之時間間隔的影響。 材料與方法　本研究取材自某醫院自1994年到2003年十年間所有住院病人之入出院紀錄，及其是否院內感染之資料與院內感染者其相關的詳細資料暨死亡資料。排除19,271名因生產住院的個案，總計282,898名住院病人資料納入本研究進行分析。其中5330名病患(8885人次)曾發生院內感染。與死亡檔連結後找到1711名死亡個案(965名在醫院死亡，746名病危出院死亡)，其中1495 (87.4%)人是在感染之後三十天內死亡。進一步將死亡率分解為侵襲率的影響及致死率的影響並評估其時間趨勢，最後利用時間序列布瓦松迴歸模式探討上述三者之間的相關。並比較台灣及美國住院病患從住院日至感染日之間時程的比較。 結果　整體而言，院內感染侵襲率於十年內降低6%，由1994年的3.34%降至2003年的3.14%。然而，院內感染致死率卻增加了55%，由1994年的13.96%增加至2003年的21.6%。因院內感染死亡的死亡率時間趨勢則上升了46%，由1994年的0.46%上升至2003年的0.67%。 結論　利用某醫院十年內住院及院內感染資料，我們採用時間序列布瓦松迴歸分析將院內感染死亡率時間趨勢分解為侵襲率及致死率兩部份的影響，來自這兩部份影響的異質性除了可以推論在院內感染控制的測量上應用多重測量方法外，關於其成因則有待未來研究繼續深入探討。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.中文摘要 6 Abstract 8 Chapter 1 Introduction 12 Chapter 2 Literature Review 15 2.1 Investigations of Nosocomial Surveillance systems 17 2.1.1 Prevalence study (cross-sectional/ transverse) 17 2.1.2 Incidence study (continuous/longitudinal) 17 2.1.3 Estimation method 18 2.2 Impact of nosocomial infections 19 2.3 Epidemiology of nosocomial infections 22 2.3.1 Prevalence surveys of nosocomial infections 22 2.3.2 Incidence of nosocomial infections 24 2.3.3 Microorganism and nosocomial infections 24 2.4 Nosocomial infections in Taiwan 25 2.5 Risk factors of nosocomial infections 28 Chapter 3 Materials and Methods 31 3.1 Setting… 31 3.2 Surveillance Data on Nosocomial Infections 31 3.3. Definitions and diagnosis of nosocomial infections 32 3.4 Collected variables 34 3.5. Main outcome measures 35 3.6 Statistical methods 36 Chapter 4 Results 39 4.1. Descriptive Data 39 4.2 Association with Attack rate and Case-fatality Rate 41 4.3 Time trend in attack rate, case-fatality rate, mortality rate, and standardized mortality ratio 43 4.3.1 Overall Trend 43 4.3.2 Trend by Pathogen 44 4.3.3 Trend by Infection Site 45 4.4 Multivariate Time-series Poisson Regression Analysis 46 4.4.1 Top ten frequency of bacteremia pathogen 47 4.5 Mean interval between admission and onset of NI for bacteremia pathogens. 48 Chapter 5 Discussion 49 5.1 Nosocomial surveillance by Time Trend in Mortality Rate, Attack Rate, and Case-fatality 49 5.2 Interpretation of Attack Rate 50 5.3 Interpretation of Case-fatality Rate 52 5.4 Pathogen and site of Infection 53 References 56 Tables and Figures 58 Table 4.1.1 Descriptive results regarding frequencies of NI and death, attack rate, case-fatality rate, and mortality rate by age gender, infection site, and speciality 58 Table 4.1.1 continue 59 Table 4.1.1 continue 59 Table 4.1.2 Cause of death 60 Table 4.1.3.1Bacteremia pathogens attack rate,case-fatality,mortality 61 Table 4.1.3.2 Respiratory tract infection pathogens attack rate,case-fatality,mortality 62 Table 4.1.3.3 Urinary tract infection pathogens attack rate,case-fatality,mortality 63 Table 4.1.3.4 Surgical site infection pathogens attack rate,case-fatality,mortality 64 Table 4.2.1 Univariate analysis of poisson regression by gender ,age, infection site, and specialty for attack rate 65 Table 4.2.1continue 66 Table 4.2.2 Odds Ratios for The relationship of death to age ,gender,cause of admission ,and episode 67 Table 4.2.3 Four major Infection site(casefatality) 68 Table 4.3.1.1 attack rate, casefatality rate, mortality rate 69 Table 4.4.1 multIvariate adjusted poisson regression (outcome infection) 70 Table 4.4.2 multiple variable adjusted poisson regression (outcome infection) 71 Table 4.4.3multiple variable adjusted poisson regression (outcome infection) 72 Table 4.4.4 multiple variable adjusted poisson regression (outcome infection) 73 Table 4.4.5 multiple variable adjusted poisson regression (outcome death) 74 Table 4.4.6 multiple variable adjusted poisson regression (outcome death) 75 Table 4.4.7 multiple variable adjusted poisson regression (outcome death) 76 Table 4.4.8 top ten pathogen of bacteremia 77 Table 4.5.1 The mean interval between admission and onset of nosocomial bloodstream infections and the estimated parameters of infection rate 78 Table 5.1.1 Summary of time trend in attack rate,case-fatality rate,and motality rate by pathogens 79 Figure 3.1 Number of discharged patients , episode of NIs , and deaths between 1994 and 2003,SKMH,Taipei,Taiwan 80 Figure 4.1.1 Major pathogens of mortality rates for top ten 81 Figure 4.3.1.1 time trend of attack rate, casefatality rate, mortality 82 Rate of NIs ,SKH 1994-2003 82 Figure 4.3.1.2 Standardized mortality ratio,SMR, national mortality rate adjusted by agegroup 83 Figure 4.3.1.3 Standardized mortality ratio,SMR, SKH mortality rate adjusted by age group 84 Figure 4.3.2.1 Time trend of attack rate ,casefatality rate mortality rate for Staphylococcus aureus 85 Figure 4.3.2.2 Time trend of attack rate ,casefatality rate mortality rate for E.coli 86 Figure 4.3.2.2 Time trend of attack rate ,casefatality rate mortality rate for yeast form fungus 87 Figure 4.3.2.3 Time trend of attack rate ,casefatality rate mortality rate for Acinetobacter spp. 88 Figure 4.3.2.4 Time trend of attack rate ,casefatality rate mortality rate for Pseudomonas aeruginosa 89 Figure 4.3.2.5 Time trend of attack rate ,casefatality rate mortality rate for Enterobacter spp. 90 Figure 4.3.2.6 Time trend of attack rate ,casefatality rate mortality rate for coagulase negative Stapylococcus 91 Figure 4.3.2.7 Time trend of attack rate ,casefatality rate mortality rate for K. pneumoniae 92 Figure 4.3.2.8 Time trend of attack rate ,casefatality rate mortality rate for E.cloacae 93 Figure 4.3.2.9 Time trend of attack rate ,casefatality rate mortality rate for no culture no pathogen 94 Figure 4.3.2.10Time trend of attack rate ,casefatality rate mortality rate for multiple pathogens 95 Figure 4.3.3.1Time trend of attack rate ,casefatality rate mortality rate for bacteremia 96 Figure 4.3.3.2Time trend of attack rate ,casefatality rate mortality rate for respiratory tract infection 97 Figure 4.3.3.3Time trend of attack rate ,casefatality rate mortality rate for urinary tract infection 98 Figure 4.3.3.4Time trend of attack rate ,casefatality rate mortality rate for surgical site infection 99 Figure 4.3.3.5 Time trend of attack rate ,casefatality rate mortality rate for other site infection 100 Figure 4.5.1 the interval between admission and infection onset cumulative infection rate 101 Figure 4.5.2 the interval between admission and infection onset cumulative infection rate 102 Figure 4.5.3 the interval between admission and infection onset cumulative infection rate 103 Figure 4.5.4 the interval between admission and infection onset cumulative infection rate 104 Figure 5.1 Time trend of nosocomial infection pathogen 105en-US院內感染侵襲率致死率死亡率布瓦松迴歸nosocomial infectionattack ratecase-fatality ratemortalityPoisson regressionthesis