Palmsten Kristin, Huybrechts Krista F, Mogun Helen, Kowal Mary K, Williams Paige L, Michels Karin B, Setoguchi Soko, Hernández-Díaz Sonia
Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America.
PLoS One. 2013 Jun 26;8(6):e67405. doi: 10.1371/journal.pone.0067405. Print 2013.
In the absence of clinical trial data, large post-marketing observational studies are essential to evaluate the safety and effectiveness of medications during pregnancy. We identified a cohort of pregnancies ending in live birth within the 2000-2007 Medicaid Analytic eXtract (MAX). Herein, we provide a blueprint to guide investigators who wish to create similar cohorts from healthcare utilization data and we describe the limitations in detail.
Among females ages 12-55, we identified pregnancies using delivery-related codes from healthcare utilization claims. We linked women with pregnancies to their offspring by state, Medicaid Case Number (family identifier) and delivery/birth dates. Then we removed inaccurate linkages and duplicate records and implemented cohort eligibility criteria (i.e., continuous and appropriate enrollment type, no private insurance, no restricted benefits) for claim information completeness.
From 13,460,273 deliveries and 22,408,810 child observations, 6,107,572 pregnancies ending in live birth were available after linkage, cleaning, and removal of duplicate records. The percentage of linked deliveries varied greatly by state, from 0 to 96%. The cohort size was reduced to 1,248,875 pregnancies after requiring maternal eligibility criteria throughout pregnancy and to 1,173,280 pregnancies after further applying infant eligibility criteria. Ninety-one percent of women were dispensed at least one medication during pregnancy.
Mother-infant linkage is feasible and yields a large pregnancy cohort, although the size decreases with increasing eligibility requirements. MAX is a useful resource for studying medications in pregnancy and a spectrum of maternal and infant outcomes within the indigent population of women and their infants enrolled in Medicaid. It may also be used to study maternal characteristics, the impact of Medicaid policy, and healthcare utilization during pregnancy. However, careful attention to the limitations of these data is necessary to reduce biases.
在缺乏临床试验数据的情况下，大型上市后观察性研究对于评估孕期用药的安全性和有效性至关重要。我们在2000 - 2007年医疗补助分析提取物（MAX）中确定了一组以活产告终的妊娠队列。在此，我们提供了一个蓝图，以指导希望从医疗保健利用数据中创建类似队列的研究人员，并详细描述了局限性。
在12 - 55岁的女性中，我们使用医疗保健利用索赔中的分娩相关代码来识别妊娠。我们通过州、医疗补助病例编号（家庭标识符）以及分娩/出生日期将怀孕女性与其后代联系起来。然后我们去除了不准确的关联和重复记录，并针对索赔信息完整性实施了队列纳入标准（即连续且适当的参保类型、无私人保险、无受限福利）。
在13460273次分娩和22408810次儿童观察中，经过关联、清理和去除重复记录后，有6107572次以活产告终的妊娠可供使用。关联分娩的百分比因州而异，从0%到96%不等。在要求整个孕期符合母亲纳入标准后，队列规模减少到1248875次妊娠，在进一步应用婴儿纳入标准后减少到1173280次妊娠。91%的女性在孕期至少服用了一种药物。
母婴关联是可行的，并产生了一个大型妊娠队列，尽管队列规模会随着纳入标准的增加而减小。MAX是研究孕期用药以及医疗补助覆盖的贫困妇女及其婴儿群体中一系列母婴结局的有用资源。它还可用于研究母亲特征、医疗补助政策的影响以及孕期的医疗保健利用情况。然而，必须仔细关注这些数据的局限性以减少偏差。
