Horbar J D, Badger G J, Lewit E M, Rogowski J, Shiono P H
Department of Pediatrics, University of Vermont College of Medicine, Burlington 05405, USA.
Pediatrics. 1997 Feb;99(2):149-56. doi: 10.1542/peds.99.2.149.
The outcomes for very low birth weight infants vary among neonatal intensive care units (NICUs), but the reasons for this variation are not well understood. We used the database of a large neonatology research network to determine whether either admission characteristics of the infants or specific characteristics of the units such as annual patient volume and the presence of a pediatric residency program could account for observed differences in neonatal mortality rates among units.
We studied 7672 infants with birth weights from 501 to 1500 g treated during 1991 and 1992 at 62 NICUs participating in the Vermont Oxford Network Database.
Overall, 14.7% of the study infants died within 28 days of birth (interquartile range 9.9% to 18.1%). The ratio of the number of observed deaths at an NICU to the number of deaths predicted based on the characteristics of infants treated at the NICU (standardized neonatal mortality ratio, [SNMR]) varied significantly among units (range 0 to 1.69, z = 4.24). There was no association between annual patient volume and either mortality rate (r = .17) or SNMR (r = .22). Observed mortality rates (17% vs 13%) and SNMR (1.04 vs .87) were both higher at the 24 hospitals with pediatric residency training programs than at the 38 hospitals without such programs. Hospitals with residency programs had higher average annual patient volumes (104 vs 66). In an analysis simultaneously adjusting for patient characteristics, volume, and presence of a residency program, neither volume (odds ratio [OR] per 10 additional cases treated 1.01, 95% confidence interval [CI], .98 to 1.04) nor presence of a pediatric residency program (OR 1.18, 95% CI, .94 to 1.47) was significantly associated with neonatal mortality risk.
There are differences in neonatal mortality rates among NICUs that cannot be explained by differences in the measured admission characteristics of the infants, suggesting that the effectiveness of medical care varies among units. Neither the annual volume of very low birth weight infants treated in a unit nor the presence of a pediatric residency training program was independently associated with neonatal mortality rates for very low birth weight infants.
极低出生体重婴儿的预后在各新生儿重症监护病房（NICU）中有所不同，但这种差异的原因尚不清楚。我们利用一个大型新生儿学研究网络的数据库，来确定婴儿的入院特征或各病房的特定特征（如年度患者数量和儿科住院医师培训项目的存在情况）是否能够解释各病房新生儿死亡率的观察差异。
我们研究了1991年和1992年在参与佛蒙特牛津网络数据库的62个NICU中接受治疗的7672名出生体重在501至1500克之间的婴儿。
总体而言，14.7%的研究婴儿在出生后28天内死亡（四分位间距为9.9%至18.1%）。各病房中，NICU观察到的死亡数与根据该NICU所治疗婴儿的特征预测的死亡数之比（标准化新生儿死亡率，[SNMR]）差异显著（范围为0至1.69，z = 4.24）。年度患者数量与死亡率（r = 0.17）或SNMR（r = 0.22）之间均无关联。在有儿科住院医师培训项目的24家医院中，观察到的死亡率（17%对13%）和SNMR（1.04对0.87）均高于没有此类项目的38家医院。有住院医师培训项目的医院年度平均患者数量更高（104对66）。在一项同时对患者特征、数量和住院医师培训项目的存在情况进行调整的分析中，数量（每多治疗10例病例的优势比[OR]为1.01，95%置信区间[CI]为0.98至1.04）和儿科住院医师培训项目的存在情况（OR为1.18，95%CI为0.94至1.47）均与新生儿死亡风险无显著关联。
NICU之间的新生儿死亡率存在差异，而这些差异无法通过所测量的婴儿入院特征差异来解释，这表明各病房的医疗护理效果有所不同。一个病房中治疗的极低出生体重婴儿的年度数量以及儿科住院医师培训项目的存在情况，均与极低出生体重婴儿的新生儿死亡率无独立关联。
