Showing papers by "Larry Rand published in 2019"

Maternal factors influencing late entry into prenatal care: a stratified analysis by race or ethnicity and insurance status

Abstract: Objective: Examine factors influencing late (> sixth month of gestation) entry into prenatal care by race/ethnicity and insurance payer.Methods: The study population was drawn from singleton live b...

Risk of preterm and early term birth by maternal drug use

Abstract: Examine the risk of preterm birth (PTB, < 37 weeks) and early term birth (37–38 weeks) for women with reported drug abuse/dependence. The population was drawn from singleton livebirths in California from 2007 to 2012. Drug abuse/dependence was determined from maternal diagnostic codes (opioid, cocaine, cannabis, amphetamine, other, or polysubstance). Relative risks, adjusted for maternal factors were calculated for PTB and early term birth. Of the 2,890,555 women in the sample, 1.7% (n = 48,133) had a diagnostic code for drug abuse/dependence. The percentage of PTBs varied from 11.6% (cannabis) to 24.3% (cocaine), compared with 6.7% of women without reported drug abuse/dependence. Women with reported drug abuse/dependence during pregnancy were at increased risk of having a PTB and all but those using cannabis were at risk of having an early term birth. Women using cocaine and polysubstance were at the highest risk of birth < 32 weeks.

Development and validation of a clinical model for preconception and early pregnancy risk prediction of gestational diabetes mellitus in nulliparous women.

Abstract: Implementation of dietary and lifestyle interventions prior to and early in pregnancy in high risk women has been shown to reduce the risk of gestational diabetes mellitus (GDM) development later in pregnancy. Although numerous risk factors for GDM have been identified, the ability to accurately identify women before or early in pregnancy who could benefit most from these interventions remains limited. As nulliparous women are an under-screened population with risk profiles that differ from their multiparous counterparts, development of a prediction model tailored to nulliparous women may facilitate timely preventive intervention and improve maternal and infant outcomes. We aimed to develop and validate a model for preconception and early pregnancy prediction of gestational diabetes mellitus based on clinical risk factors for nulliparous women. A risk prediction model was built within a large California birth cohort including singleton live birth records from 2007-2012. Model accuracy was assessed both internally and externally, within a cohort of women who delivered at University of Iowa Hospitals and Clinics between 2009-2017, using discrimination and calibration. Differences in predictive accuracy of the model were assessed within specific racial/ethnic groups. The prediction model included five risk factors: race/ethnicity, age at delivery, pre-pregnancy body mass index, family history of diabetes, and pre-existing hypertension. The area under the curve (AUC) for the California internal validation cohort was 0.732 (95% confidence interval (CI) 0.728, 0.735), and 0.710 (95% CI 0.672, 0.749) for the Iowa external validation cohort. The model performed particularly well in Hispanic (AUC 0.739) and Black women (AUC 0.719). Our findings suggest that estimation of a woman's risk for GDM through model-based incorporation of risk factors accurately identifies those at high risk (i.e., predicted risk >6%) who could benefit from preventive intervention encouraging prompt incorporation of this tool into preconception and prenatal care.

Associations between unstable housing, obstetric outcomes, and perinatal health care utilization

Abstract: Background While there is a growing interest in addressing social determinants of health in clinical settings, there are limited data on the relationship between unstable housing and both obstetric outcomes and health care utilization. Objective The objective of the study was to investigate the relationship between unstable housing, obstetric outcomes, and health care utilization after birth. Study Design This was a retrospective cohort study. Data were drawn from a database of liveborn neonates linked to their mothers’ hospital discharge records (2007–2012) maintained by the California Office of Statewide Health Planning and Development. The analytic sample included singleton pregnancies with both maternal and infant data available, restricted to births between the gestational age of 20 and 44 weeks, who presented at a hospital that documented at least 1 woman as having unstable housing using the International Classification of Diseases, ninth edition, codes (n = 2,898,035). Infants with chromosomal abnormalities and major birth defects were excluded. Women with unstable housing (lack of housing or inadequate housing) were identified using International Classification of Diseases, ninth edition, codes from clinical records. Outcomes of interest included preterm birth ( 2 days; cesarean delivery, >4 days), emergency department visit within 3 months and 1 year after delivery, and readmission within 3 months and 1 year after delivery. We used exact propensity score matching without replacement to select a reference population to compare with the sample of women with unstable housing using a one-to-one ratio, matching for maternal age, race/ethnicity, parity, prior preterm birth, body mass index, tobacco use during pregnancy, drug/alcohol abuse during pregnancy, hypertension, diabetes, mental health condition during pregnancy, adequacy of prenatal care, education, and type of hospital. Odds of an adverse obstetric outcome were estimated using logistic regression. Results Of 2794 women with unstable housing identified, 83.0% (n = 2318) had an exact propensity score–matched control. Women with an unstable housing code had higher odds of preterm birth (odds ratio, 1.2, 95% confidence interval, 1.0–1.4, P Conclusion Unstable housing documentation is associated with adverse obstetric outcomes and high health care utilization. Housing and supplemental income for pregnant women should be explored as a potential intervention to prevent preterm birth and prevent increased health care utilization.

An Evaluation of Sexually Transmitted Infection and Odds of Preterm or Early-Term Birth Using Propensity Score Matching.

Abstract: BACKGROUND Few studies have examined the relationship between sexually transmitted infections (STIs) and preterm birth (<37 weeks gestation) by subtype (<32 weeks, 32-36 weeks, spontaneous, provider-initiated). Here, we evaluate the odds of preterm (by subtype) and early-term (37 and 38 weeks gestation) birth in women with an STI compared with a propensity score-matched reference population. METHODS The sample was selected from California births in 2007 to 2012. Sexually transmitted infection was defined as a maternal diagnosis of chlamydia, gonorrhea, or syphilis in the birth certificate or hospital discharge record. A reference sample of women without an STI was selected using exact propensity score matching on maternal factors. Odds of preterm and early-term birth were calculated. RESULTS Sixteen thousand three hundred twelve women were identified as having an STI during pregnancy and an exact propensity score-matched control was identified for 97.2% (n = 15,860). Women with an indication of syphilis during pregnancy were at 1.6 times higher odds of having a preterm birth and, in particular, at elevated odds of a birth less than 32 weeks due to preterm premature rupture of the membranes or provider-initiated birth (odds ratios 4.0-4.2). Women with gonorrhea were at increased odds of a preterm birth, a birth less than 32 weeks, or an early-term birth (odds ratios 1.2-1.8). Chlamydia did not raise the odds of either a preterm or early-term birth. CONCLUSIONS Gonorrhea and syphilis increased the odds of a preterm birth. Gonorrhea also increased the odds of an early-term birth. Chlamydia did not raise the odds of an early birth.

Previous Adverse Outcome of Term Pregnancy and Risk of Preterm Birth in Subsequent Pregnancy.

Abstract: Objective Evaluate risk of preterm birth (PTB, < 37 completed weeks’ gestation) among a population of women in their second pregnancy with previous full term birth but other adverse pregnancy outcome. Methods The sample included singleton live born infants between 2007 and 2012 in a birth cohort file maintained by the California Office of Statewide Health Planning and Development. The sample was restricted to women with two pregnancies resulting in live born infants and first birth between 39 and 42 weeks’ gestation. Logistic regression was used to calculate the risk of PTB in the second birth for women with previous adverse pregnancy outcome including: small for gestational age (SGA) infant, preeclampsia, placental abruption, or neonatal death (≤ 28 days). Risks were adjusted for maternal factors recorded for second birth. Results The sample included 133,622 women. Of the women with any previous adverse outcome, 4.7% had a PTB while just 3.0% of the women without a previous adverse outcome delivered early (relative risk adjusted for maternal factors known at delivery 1.4, 95% CI 1.3–1.5). History of an SGA infant, placental abruption, or neonatal death increased the adjusted risk of PTB in their second birth by 1.5–3.7-fold. History of preeclampsia did not elevate the risk of a preterm birth in the subsequent birth. Conclusions for Practice The findings indicate that women with previous SGA infant, placental abruption, or neonatal death, despite a term delivery, may be at increased risk of PTB in the subsequent birth. These women may be appropriate participates for future interventions aimed at reduction in PTB.