Karch André, Castell Stefanie, Schwab Frank, Geffers Christine, Bongartz Hannah, Brunkhorst Frank M, Gastmeier Petra, Mikolajczyk Rafael T
Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany German Center for Infection Research, Hannover-Braunschweig Site, Hannover-Braunschweig, Germany
Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
J Clin Microbiol. 2015 Feb;53(2):648-52. doi: 10.1128/JCM.02944-14. Epub 2014 Dec 17.
Early and appropriate blood culture sampling is recommended as a standard of care for patients with suspected bloodstream infections (BSI) but is rarely taken into account when quality indicators for BSI are evaluated. To date, sampling of about 100 to 200 blood culture sets per 1,000 patient-days is recommended as the target range for blood culture rates. However, the empirical basis of this recommendation is not clear. The aim of the current study was to analyze the association between blood culture rates and observed BSI rates and to derive a reference threshold for blood culture rates in intensive care units (ICUs). This study is based on data from 223 ICUs taking part in the German hospital infection surveillance system. We applied locally weighted regression and segmented Poisson regression to assess the association between blood culture rates and BSI rates. Below 80 to 90 blood culture sets per 1,000 patient-days, observed BSI rates increased with increasing blood culture rates, while there was no further increase above this threshold. Segmented Poisson regression located the threshold at 87 (95% confidence interval, 54 to 120) blood culture sets per 1,000 patient-days. Only one-third of the investigated ICUs displayed blood culture rates above this threshold. We provided empirical justification for a blood culture target threshold in ICUs. In the majority of the studied ICUs, blood culture sampling rates were below this threshold. This suggests that a substantial fraction of BSI cases might remain undetected; reporting observed BSI rates as a quality indicator without sufficiently high blood culture rates might be misleading.
早期且恰当的血培养采样被推荐作为疑似血流感染（BSI）患者的标准治疗措施，但在评估BSI的质量指标时却很少被考虑。迄今为止，推荐每1000个患者日采集约100至200套血培养作为血培养率的目标范围。然而，这一推荐的经验依据并不明确。本研究的目的是分析血培养率与观察到的BSI率之间的关联，并得出重症监护病房（ICU）血培养率的参考阈值。本研究基于参与德国医院感染监测系统的223个ICU的数据。我们应用局部加权回归和分段泊松回归来评估血培养率与BSI率之间的关联。每1000个患者日低于80至90套血培养时，观察到的BSI率随血培养率的增加而升高，而高于此阈值则无进一步升高。分段泊松回归将阈值定位在每1000个患者日87套（95%置信区间，54至120）血培养。仅三分之一的被调查ICU血培养率高于此阈值。我们为ICU的血培养目标阈值提供了经验依据。在大多数研究的ICU中，血培养采样率低于此阈值。这表明相当一部分BSI病例可能未被检测到；在血培养率不够高的情况下将观察到的BSI率作为质量指标报告可能会产生误导。
