Gaynes R P, Martone W J, Culver D H, Emori T G, Horan T C, Banerjee S N, Edwards J R, Jarvis W R, Tolson J S, Henderson T S
Hospital Infections Program, Centers for Disease Control, Atlanta, Georgia 30333.
Am J Med. 1991 Sep 16;91(3B):192S-196S. doi: 10.1016/0002-9343(91)90368-8.
To determine nosocomial infection (NI) rates among neonatal intensive care units (NICUs) that are useful for interhospital comparison, we analyzed data reported in 1986-1990 from 35 hospitals that have level III NICUs and used standard National Nosocomial Infections Surveillance protocols and NI site definitions. Overall rates of NI were calculated as the number of NI per 100 patients (overall NI patient rates) or the number of NI per 1,000 NICU patient-days (overall NI patient-day rates). A strong positive association was found between overall NI patient rates and the neonates' average length of stay, a marker for duration of exposure to important risk factors. No correlation was found between overall NI patient-day rates and average length of stay. However, a strong positive correlation between overall NI patient-day rates and a measure of device utilization (total device-days/total patient-days x 100) was found. Additionally, a positive correlation between overall NI patient rates and device utilization was found. Stratification among the three birthweight groups (less than 1,500 g, 1,500-2,500 g, greater than 2,500 g) did not eliminate the need to control for variations in these factors among NICUs. Device-associated, device-day infection rates, calculated as the number of umbilical or central line-associated blood-stream infections per 1,000 umbilical or central line-days and the number of ventilator-associated pneumonias per 1,000 ventilator days, were not correlated with a unit's site-specific device utilization. These data suggest that calculation of device-associated NI rates in NICUs using device-days as the denominator helps to control for the duration of exposure to the primary risk factor and will be more meaningful for purposes of interhospital comparison.
为确定可用于医院间比较的新生儿重症监护病房（NICU）的医院感染（NI）率，我们分析了1986 - 1990年期间35家设有三级NICU的医院报告的数据，并采用了标准的国家医院感染监测方案和NI部位定义。NI的总体发生率按每100例患者的NI数（总体NI患者发生率）或每1000个NICU患者日的NI数（总体NI患者日发生率）计算。总体NI患者发生率与新生儿平均住院时间（这是暴露于重要危险因素持续时间的一个指标）之间存在强正相关。总体NI患者日发生率与平均住院时间之间未发现相关性。然而，发现总体NI患者日发生率与设备使用率（总设备日数/总患者日数×100）之间存在强正相关。此外，总体NI患者发生率与设备使用率之间也存在正相关。在三个出生体重组（小于1500克、1500 - 2500克、大于2500克）之间进行分层，并不能消除控制NICU之间这些因素差异的必要性。以每1000个脐静脉或中心静脉导管日的脐静脉或中心静脉导管相关血流感染数以及每1000个呼吸机日的呼吸机相关性肺炎数计算的与设备相关的设备日感染率，与单位特定的设备使用率无关。这些数据表明，以设备日数为分母计算NICU中与设备相关的NI率有助于控制暴露于主要危险因素的持续时间，并且对于医院间比较而言将更有意义。
