Department of Health Policy & Management, Harvard T.H. Chan School of Public Health, and the Department of Population Medicine, Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, Massachusetts; the National Rural Health Association, Washington, DC; and the College of Medicine, University of South Florida, Tampa, Florida.
Obstet Gynecol. 2024 Oct 1;144(4):526-535. doi: 10.1097/AOG.0000000000005704. Epub 2024 Aug 22.
The National Health Service Corps (NHSC) attracts clinicians to Health Professional Shortage Areas (HPSAs) through scholarships and loan repayments. Since 2009, the NHSC workforce, including maternity care clinicians, has substantially expanded. This study evaluates the association between NHSC expansion and prenatal care and birth outcomes.
In this quasi-experimental study, we adopted a generalized difference-in-differences design to compare changes in prenatal care and birth outcomes from 2005 to 2019 using birth certificate data. Counties designated as HPSAs without any NHSC maternity care clinicians throughout the study period were control counties, and those without such clinicians before 2009 but receiving them after 2009 were treated counties. Outcome measures include a count variable of number of prenatal visits and four dichotomous variables: prenatal care initiation in the first trimester, adequacy of prenatal care, preterm birth, and low birth weight. We estimated negative binomial models for number of prenatal visits and linear probability models for the dichotomous outcomes, adjusting for maternal characteristics, non-NHSC clinician density, and state-level policies. Stratified analyses were also conducted on the basis of birthing people's demographics and county-level characteristics.
Our sample comprised 12,980,111 live births between 2005 and 2019 by individuals residing in 1,254 HPSA counties without any NHSC maternity care clinicians before 2009, including 222 counties that received such clinicians after 2009. Compared with control counties, pregnant people in treated counties experienced significant increases in prenatal visits (211 more prenatal visits relative to baseline of 11,226 visits per 1,000 births, P <.001) and in the likelihood of receiving adequate prenatal care (1.43 percentage point increase relative to baseline of 67.0 percentage points, P <.01). Although the NHSC expansion improved prenatal care use for all racial and ethnic groups, pregnant people residing in urban and high social vulnerability areas benefited most. Improvements in birth outcomes were observed only among certain subgroups such as a 0.91 percentage point reduction in preterm birth (relative to baseline of 12.6 percentage points, P <.001) and a 0.87 percentage point reduction in low birth weight (relative to baseline of 8.2 percentage points, P <.05) among pregnant people living in full-county HPSAs.
The NHSC expansion since 2009 was associated with increases in prenatal care utilization, particularly among vulnerable populations. Although improvements were not observed in birth outcomes overall with NHSC expansion, modest reductions were observed in preterm birth and low birth weight in subsets of the population.
国家卫生服务团（NHSC）通过奖学金和贷款偿还来吸引临床医生到卫生专业人员短缺地区（HPSA）工作。自 2009 年以来，NHSC 工作人员（包括产妇保健临床医生）大幅增加。本研究评估了 NHSC 扩张与产前护理和分娩结果之间的关联。
在这项准实验研究中，我们采用广义差分法设计，使用出生证明数据，比较 2005 年至 2019 年期间产前护理和分娩结果的变化。在整个研究期间没有任何 NHSC 产妇保健临床医生的被指定为 HPSA 的县为对照县，而在 2009 年之前没有此类临床医生但在 2009 年之后有此类临床医生的县为治疗县。结果衡量指标包括产前检查次数的计数变量和四个二分变量：孕早期开始产前护理、产前护理充足性、早产和低出生体重。我们针对产前检查次数进行了负二项式模型估计，针对二分变量结果进行了线性概率模型估计，同时调整了产妇特征、非 NHSC 临床医生密度和州级政策。还根据分娩者的人口统计学特征和县级特征进行了分层分析。
我们的样本包括 2005 年至 2019 年间居住在 1254 个没有任何 NHSC 产妇保健临床医生的 HPSA 县的 12980111 名活产儿，其中包括 2009 年后获得此类临床医生的 222 个县。与对照县相比，治疗县的孕妇接受产前护理的次数显著增加（与 11226 次/每 1000 例活产的基线相比，增加了 211 次，P<.001），接受足够产前护理的可能性也有所增加（与 67.0%的基线相比，增加了 1.43 个百分点，P<.01）。尽管 NHSC 的扩张改善了所有种族和族裔群体的产前护理使用情况，但居住在城市和高社会脆弱地区的孕妇受益最大。仅在某些亚组中观察到出生结果的改善，例如早产率降低了 0.91 个百分点（与 12.6%的基线相比，P<.001），低出生体重率降低了 0.87 个百分点（与 8.2%的基线相比，P<.05）。
自 2009 年以来，NHSC 的扩张与产前护理利用率的增加有关，特别是在弱势群体中。尽管 NHSC 扩张并未总体上改善出生结果，但在人口的某些亚组中，早产和低出生体重的情况略有减少。
