Obstetric delivery volume, regionalization, and maternal and infant outcomes

摘要 美国的婴儿和孕产妇死亡率和发病率远远高于其他国家 发达国家。这些不良结果的潜在驱动因素之一是医院的特点 女性分娩，尤其是年分娩量。有证据表明交付量 影响孕产妇结局（死亡率和严重发病率），但这一证据并不适用于所有情况 产妇结局或所有类型地点的结果，并且经常忽略胎儿死亡 分析。此外，还没有仔细检查产科容量对关节的影响。 母婴结局二元关系，或产科容量如何改变观察到的新生儿改善 NICU 的死亡率和发病率。最后，许多研究仅关注于 早产儿，忽略总分娩量、慢性疾病或共存并发症， 和低风险交付。两项较小的欧洲研究发现，体积之间存在关联 足月、低风险婴儿的分娩和新生儿结局，而不检查产妇结局。 医院分娩量可能是导致美国生育结果不佳的一个原因 具有重大的政策影响。产科服务的一些整合可能会带来好处， 但整合和访问之间存在权衡，没有关于适当的数据 阈值，或者当常规获得医疗服务的机会有限时，例如农村地区，这些阈值如何变化 地区。在 20 世纪 90 年代，葡萄牙关闭了所有交付量低于 1500 次/年的交付服务，并且 孕产妇死亡率从9.2/10万下降到5.3/10万。葡萄牙同时 关闭了所有小型新生儿重症监护室，因此导致新生儿（8.1 至 2.9/1000）和围产儿人数大幅下降 （16.4 至 6.6/1000）死亡率可能是由 NICU 和产科容量的变化造成的。同时 这些数据令人信服，患者风险和在不同地区接生婴儿的医院之间存在较大差异 美国需要创新研究来为美国和州政策提供有关如何组织产科护理的信息。 拟议的研究将解决以下具体目标： 目标1：产科服务量与母婴关系如何 发病率和死亡率（包括胎儿死亡）？这些影响很大程度上取决于患者风险吗？ 目标 2：农村地区与城市地区的配送量对数量结果的影响是否存在差异？ 我们将使用链接的生命统计数据 - 1995 年来自加利福尼亚州、马萨诸塞州、密苏里州、宾夕法尼亚州、南卡罗来纳州和西澳州的患者出院数据 - 2020。我们将利用数据的面板性质（随着时间的推移对每家医院的重复观察）来 控制影响结果的未观察到的医院特定因素。目标是确定交付 优化孕妇及其婴儿的结果所需的数量，允许证据- 州和国家层面的政策指导围产期分娩系统的发展。

Abstract The US infant and maternal mortality and morbidity rates are far above those for the rest of the developed world. One potential driver of these poor outcomes is the characteristics of hospitals where women deliver, especially the annual delivery volume. There is some evidence that the volume of deliveries affects maternal outcomes (mortality and serious morbidity), but this evidence is not consistent for all maternal outcomes or across all types of locations and has frequently omitted fetal deaths from the analyses. Further, there has not been a careful examination of the effect of obstetric volume on joint maternal-infant outcomes dyad, or how obstetric volume modifies the observed improvements in neonatal mortality and morbidity at NICUs. Finally, many of these studies have focused only on the volume of preterm infants, ignoring overall delivery volume, chronic medical conditions or co-existing complications, and low-risk deliveries. Two smaller European studies have found and association between the volume of the deliveries of term, low-risk infants and newborn outcomes, without examining maternal outcomes. That hospital delivery volume could be a contributor to the poor US reproductive outcomes could have significant policy implications. There could be benefits from some consolidation of obstetric services, but there are trade-offs between consolidation and access, with no data on either the appropriate thresholds, or how such thresholds change when routine access to medical care is limited, such as rural areas. In the 1990s Portugal closed all deliveries services with a volume <1500 deliveries/year and experienced a decrease in the maternal mortality rate from 9.2 to 5.3/100,000. Portugal simultaneously closed all small NICUs, so the resulting very large decrease in neonatal (8.1 to 2.9/1000) and perinatal (16.4 to 6.6/1000) mortality could have resulted from either changes in NICU and obstetric volume. While such data is compelling, the larger variation in both patient risk and hospitals that deliver infants in the United States requires innovative studies to inform US and state policy about how organize obstetric care. The proposed study will address the following specific aims: Aim 1: What are the relationships between the volume of obstetric services and maternal and infant morbidity and mortality (including fetal deaths)? Do these effects very by patient risk? Aim 2: Are there differences in the volume-outcome effects of delivery volume for rural vs. urban areas? We will use linked vital statistics-patient discharge data from CA, MA, MO, PA, SC and WA for 1995- 2020. We will exploit the panel nature of the data (repeated observations of each hospital over time) to control for unobserved, hospital-specific factors that affect outcomes. The objective is to identify the delivery volumes needed to optimize the outcomes for pregnant women and their babies, allowing for evidence- based policies at the state and national-level to guide the development of perinatal delivery systems.