Department of Epidemiology and Biostatistics, University of California, San Francisco.
Department of Global Health Sciences, University of California, San Francisco.
JAMA Netw Open. 2024 Sep 3;7(9):e2435887. doi: 10.1001/jamanetworkopen.2024.35887.
Preterm birth (PTB) (gestational age <37 weeks) is a major cause of infant mortality and morbidity in the US and is marked by racial and ethnic and socioeconomic inequities. Further research is needed to elucidate the association of risk and protective factors with trends in PTB rates and with related inequities.
To describe the association of PTB rates with inequities as well as related risk and protective factors over the past decade in a US population-based cohort.
DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study of singleton live births in California from January 1, 2011, to December 31, 2022, was conducted using vital statistics records and hospital records. The cohort included births with a gestational age of 22 to 44 weeks.
Preterm birth rates by racial and ethnic group and by public and nonpublic insurance (considered as a proxy for socioeconomic status) were studied across years. Log-linear regression (relative risks with 95% CIs) was used to evaluate risk and protective factors within groups. Associations of PTB rates with risk and protective factors were assessed.
This study included 5 431 018 singleton live births to individuals who identified as American Indian or Alaska Native (0.3%), Asian (14.2%), Black (4.9%), Hispanic (47.8%), or White (27.0%). A total of 43.1% of births were to individuals with public health insurance. From 2011 to 2022, the overall PTB rate increased from 6.8% to 7.5% (change [SE], 10.6% [0.6%]; z score of 18.5; P < .001). Differences in PTB rates and associated changes were observed for racial and ethnic groups and insurance groups. For example, 2022 PTB rates ranged from 5.8% among White individuals with nonpublic insurance to 11.3% among Black individuals with public health insurance. From 2011 to 2022, PTB rates decreased from 9.1% to 8.8% (change [SE], -3.5% [4.2]; z score of -0.8; P = .42) among Black individuals with nonpublic insurance, whereas they increased from 6.4% to 9.5% (change [SE], 49.8% [16.0%]; z score of 3.1; P = .002) among American Indian or Alaska Native individuals with nonpublic insurance. Increases in some risk factors (eg, preexisting diabetes, sexually transmitted infections, mental health conditions) were observed in most groups, and decreases in some protective factors (eg, participation in the California Women, Infants, and Children program) (P for trend < .001 from 2011 to 2021) were observed mostly in low-income groups.
In this cohort study of singleton live births in California, PTB rates increased in many groups. Persistent racial and ethnic and socioeconomic inequities were also observed. Changes in risk and protective factors provided clues to patterns of PTB. These data point to an urgent need to address factors associated with PTB at both the individual and population levels.
早产（PTB）（妊娠年龄<37 周）是美国婴儿死亡率和发病率的主要原因，并且存在种族、民族和社会经济不平等的现象。需要进一步研究，以阐明风险和保护因素与 PTB 率的趋势以及相关的不平等现象之间的关系。
描述过去十年中，在美国人群队列中，PTB 率与不平等现象以及相关的风险和保护因素之间的关系。
设计、地点和参与者：这是一项回顾性队列研究，纳入了 2011 年 1 月 1 日至 2022 年 12 月 31 日加利福尼亚州的单胎活产，使用生命统计记录和医院记录。队列包括妊娠 22 至 44 周的分娩。
研究了不同种族和民族群体以及公共和非公共保险（被视为社会经济地位的代表）之间的 PTB 率的变化情况。使用对数线性回归（相对风险比及其 95%置信区间）来评估群体内的风险和保护因素。评估了 PTB 率与风险和保护因素之间的关系。
本研究纳入了 5431018 名美国印第安人或阿拉斯加原住民（0.3%）、亚裔（14.2%）、黑人（4.9%）、西班牙裔（47.8%）或白人（27.0%）的单胎活产。共有 43.1%的分娩对象拥有公共医疗保险。从 2011 年到 2022 年，整体 PTB 率从 6.8%上升至 7.5%（变化[SE]，10.6%[0.6%]；z 分数为 18.5；P<0.001）。不同的种族和民族群体以及保险群体的 PTB 率和相关变化情况存在差异。例如，白人人群中未参保者的 2022 年 PTB 率为 5.8%，而参保公共医疗保险的黑人人群的 PTB 率为 11.3%。从 2011 年到 2022 年，黑人人群中未参保者的 PTB 率从 9.1%降至 8.8%（变化[SE]，-3.5%[4.2]；z 分数为-0.8；P=0.42），而美国印第安人或阿拉斯加原住民人群中未参保者的 PTB 率从 6.4%升至 9.5%（变化[SE]，49.8%[16.0%]；z 分数为 3.1；P=0.002）。大多数群体中，一些风险因素（如糖尿病前期、性传播感染、心理健康状况）的增加（P<0.001），而一些保护因素（如参加加利福尼亚妇女、婴儿和儿童计划）的减少（P<0.001）主要发生在低收入群体中。
在这项对加利福尼亚州单胎活产的队列研究中，许多群体的 PTB 率都有所上升。种族、民族和社会经济不平等现象仍然存在。风险和保护因素的变化为 PTB 模式提供了线索。这些数据表明，迫切需要在个体和人群层面上解决与 PTB 相关的因素。
