The effect of WIC and Medicaid on infant mortality in the United States

Predictors of WIC uptake among low-income pregnant individuals: a longitudinal nationwide analysis

BACKGROUND

Nutrition during pregnancy is important for maternal and infant health. The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) provides nutritional support for low-income pregnant and postpartum individuals and children under the age of 5 y. However, WIC participation was in decline in the decade leading up to 2019.

OBJECTIVES

This study examined individual and state predictors associated with WIC uptake among eligible individuals so as to identify subgroups for targeted intervention to improve participation.

METHODS

Data came from the 2004-2019 waves of the Pregnancy Risk Assessment Monitoring System (PRAMS), a national survey of individuals who recently gave birth (N = 288,531). Multivariable logistic regressions were used to examine individual- and state-level and temporal predictors of WIC uptake among WIC-eligible respondents.

RESULTS

Among WIC-eligible respondents, ages of >35 (OR: 0.68; 95% CI: 0.66, 0.70), more than high school education (OR: 0.63; 95% CI: 062, 0.65), English language proficiency (OR: 0.71; 95% CI: 0.68, 0.74), being married (OR: 0.70; 95% CI: 0.69, 0.72), White race, smaller family size, not having prepregnancy diabetes, and higher income were associated with lower odds of WIC uptake. Respondents in states with higher earned income tax credit rates and in the Northeast, Midwest, and West (compared with the South) had lower WIC uptake. Respondents in states with higher gross domestic product, higher unemployment rates, higher Supplemental Nutrition Assistance Program, Temporary Assistance for Needy Families, and Medicaid caseloads, and Democrat governors had higher uptake; however, effect estimates were small and may not represent a meaningful change. Associations were the strongest during 2009-2015 than during other years, particularly for race/Hispanic origin, language, marital status, prepregnancy diabetes, family size, and prepregnancy.

CONCLUSIONS

This study identified several individual- and state-level characteristics associated with WIC uptake among low-income eligible respondents, paving the way for future interventions to target key subgroups to improve program participation.

Trends in health equity in mortality in the United States, 1969-2019

RATIONALE

Health equity is a significant concern of public health, yet a comprehensive assessment of health equity in the United States over time is lacking. While one might presume that overall health will improve with rising living standards, no such presumption is warranted for health equity, which may decline even as average health improves.

OBJECTIVES

To assess trends in national and state-level health equity in mortality for people up to age 25, ages 25-64 and aged 65 and older.

METHODS

A health equity metric was calculated as the weighted mean life expectancy relative to a benchmark level, defined as the life expectancy of the most socially-privileged subpopulation (white, non-Latinx males with a college education or higher).We analyzed 114,558,346 death records from the National Center for Health Statistics, from January 1, 1969 to December 31, 2019 to estimate health equity annually at the national and state-level. Using ICD-9/ICD-10 classification codes, inequities in health were decomposed by major causes of death.

RESULTS

From 1969 to 2019, health equity in the United States improved (+0.36 points annually [95% CI 0.31-0.41]), albeit at a slower rate over the last two decades (+0.08 points annually [95% CI 0.03-0.14] from 2000 to 2019, compared to +0.57 points annually from 1969 to 2000 [95% CI 0.50-0.65]). Health equity among those under 25 improved substantially (+0.82 points annually [95% CI 0.75-0.89]) but remained flat for adults 25-64 (-0.01 points annually [95% CI -0.03-0.003]) For those over 65, health equity displayed a downward trend (-0.08 points annually [95% CI -0.09 to -0.07]). Gains in equity from reduced unintentional injuries and homicides have been largely offset by rising mortality attributable to drug overdoses.

CONCLUSIONS

The US is failing to advance health equity, especially for adults. Keeping policy-makers accountable to a summary measure of health equity may help coordinate efforts at improving population health.

Maternal Adverse Childhood Experiences, Paternal Involvement, and Infant Health

OBJECTIVES

To assess the interplay between maternal exposure to adverse childhood experiences (ACEs) and father's acknowledgment of paternity (AOP; a proxy for paternal involvement) in the risk of low birth weight (<2500 grams) and preterm birth (<37 weeks) among offspring.

STUDY DESIGN

Data come from the 2018 North Dakota and South Dakota Pregnancy Risk Assessment Monitoring System (n = 1896). Logistic regression models were used to assess low birth weight and preterm birth outcomes. Moderation analyses are conducted to assess the interaction between maternal ACEs and father's AOP.

RESULTS

Moderation analyses demonstrated a positive interaction between an accumulating number of maternal ACEs and being unmarried without AOP for low birth weight and preterm birth. Upon comparing newborns of unmarried women without AOP, those whose mothers were exposed to 4 or more ACEs had a 3.74 times greater probability of low birth weight (0.050 vs 0.187) and a 1.74 times greater probability of preterm birth (0.085 vs 0.148) than those whose mothers reported no ACE exposure.

CONCLUSIONS

Exposure to accumulating ACEs substantially increases the risk of deleterious infant health outcomes, but only for newborns of unmarried women without AOP. Future research should assess the efficacy of interventions that can mitigate the impact of maternal ACEs in the absence of father's AOP.

Incarceration Exposure During Pregnancy and Infant Health: Moderation by Public Assistance

OBJECTIVES

To assess the relationship between exposure to incarceration during pregnancy and adverse infant health outcomes: low birth weight (<2500 g), very low birth weight (<1500 g), preterm birth (<37 weeks), and very preterm birth (≤33 weeks), and to evaluate the moderating role of receiving public assistance benefits (Special Supplemental Nutrition Program for Women, Infants, and Children and Medicaid) during pregnancy in this process.

STUDY DESIGN

The current study employs data from the Pregnancy Risk Assessment Monitoring System, 2009-2017. Logistic regression models were used to assess the association between incarceration of a woman or her partner in the year before birth, the receipt of public assistance during pregnancy, and postpartum infant health. Moderation analyses were conducted by interacting forms of public assistance and incarceration exposure.

RESULTS

Exposure to incarceration either personally or vicariously through a partner increased all 4 adverse infant health outcomes. However, moderation analyses demonstrated that public assistance benefits and incarceration have a negative interaction, indicating that public assistance might buffer against the harmful effects of incarceration exposure during pregnancy on infant health.

CONCLUSIONS

Incarceration exposure during pregnancy poses a significant risk for adverse infant health outcomes. However, the receipt of public assistance benefits including Special Supplemental Nutrition Program for Women, Infants, and Children and Medicaid may mitigate this risk. Expanded access to public assistance for women exposed to incarceration during pregnancy holds promise to improve infant health outcomes.

Coordinated Care Organizations and mortality among low-income infants in Oregon

OBJECTIVE

To examine the impact of Oregon's Coordinated Care Organizations (CCOs), an accountable care model for Oregon Medicaid enrollees implemented in 2012, on neonatal and infant mortality.

DATA SOURCES

Oregon birth certificates linked with death certificates, and Medicaid/CCO enrollment files for years 2008-2016.

STUDY DESIGN

The sample consisted of the pre-CCO birth cohort of 135 753 infants (August 2008-July 2011) and the post-CCO birth cohort of 148 650 infants (August 2012-December 2015). We used a difference-in-differences probit model to estimate the difference in mortality between infants enrolled in Medicaid and infants who were not enrolled. We examined heterogeneous effects of CCOs for preterm and full-term infants and the impact of CCOs over the implementation timeline. All models were adjusted for maternal and infant characteristics and secular time trends.

PRINCIPAL FINDINGS

The CCO model was associated with a 56 percent reduction in infant mortality compared to the pre-CCO level (-0.20 percentage points [95% CI: -0.35; -0.05]), and also with a greater reduction in infant mortality among preterm infants compared to full-term infants. The impact on mortality grew in magnitude over the postimplementation timeline.

CONCLUSIONS

The CCO model contributed to a reduction in mortality within the first year of birth among infants enrolled in Medicaid.

Impact of federal transfers upon US infant mortality rates: a secondary analysis using a fixed effects regression approach

OBJECTIVES

In order to improve health outcomes, the federal government allocates hundreds of billions of annual dollars to individual states in order to further the well-being of its citizens. This study examines the impact of such federal intergovernmental transfers on reducing state-level infant mortality rates.

SETTING

Annual data are collected from all 50 US states between 2004 and 2013.

PARTICIPANTS

Entire US population under the age of 1 year between 2004 and 2013.

PRIMARY AND SECONDARY OUTCOME MEASURES

State-level infant mortality rate, neonatal mortality rate and postneonatal mortality rate.

RESULTS

Using a fixed effects regression model to control for unmeasurable differences between states, the impact of federal transfers on state-level infant mortality rates is estimated. After controlling for differences across states, increases in per capita federal transfers are significantly associated with lower infant, neonatal and postneonatal mortality rates. Holding all other variables constant, a $200 increase in the amount of federal transfers per capita would save one child's life for every 10 000 live births.

CONCLUSIONS

Considerable debate exists regarding the role of federal transfers in improving the well-being of children and families. These findings indicate that increases in federal transfers are strongly associated with reductions in infant mortality rates. Such benefits should be carefully considered when state officials are deciding whether to accept or reject federal funds.

Audacious Goals - 2.0 The Global Initiative for Children's Surgery

This is the Presidential Address given at the 48th Annual Meeting of the American Pediatric Surgical Association (APSA) held in Hollywood, Florida, from May 4-7, 2017.

Medicaid's lasting impressions: Population health and insurance at birth

This article examines lasting mortality improvements associated with availability of Medicaid at time and place of birth. Using the US Vital Statistics (1959-2010), I exploit the variation in when each of the 50 states adopted Medicaid to estimate overall infant mortality improvements that coincided with Medicaid participation. 0.23 less infant deaths per 1000 live births was associated with states' Medicaid implementation. Second, I find lasting associations between Medicaid and mortality improvements across the life-course. I build state-specific cohort life-tables and regress age-specific mortality on availability of Medicaid in their states at time of birth. Cohorts born after Medicaid adoption had lower mortality rates throughout childhood and into adulthood. Being born after Medicaid was associated with between 2.03 and 3.64 less deaths per 100,000 person-years in childhood and between 1.35 and 3.86 less deaths per 100,000 person-years in the thirties. The association between Medicaid at birth and mortality was the strongest in the oldest age group (36-40) in this study.

Factors associated with difficulty accessing health care for infants in Canada: mothers' reports from the cross-sectional Maternity Experiences Survey

Background

Approximately 13% of Canadian mothers report difficulty accessing health care for their infants, yet little is known about the factors associated with difficulty. Therefore, we examined factors associated with difficulty accessing non-routine health care for Canadian infants, from birth to 14 months of age, as reported by their mothers.

Methods

Data was drawn from the Maternity Experiences Survey (MES), a cross-sectional, nationally representative survey of mothers who gave birth between November 2005 and May 2006, aged 15 years or older, and lived with their infants at the time of survey administration. A multivariable logistic regression analysis was conducted to determine factors associated with reporting difficulty, with difficulty defined as a mother reporting it being somewhat or very difficult to access a health care provider.

Results

Analysis of 2832 mothers who reported needing to access a health care provider for their infant for a non-routine visit found that 13% reported difficulty accessing a provider. Factors associated with reporting difficulty were: residing in Quebec (aOR 1.89, 95% CI: 1.31–2.73), being an immigrant (aOR 1.58, 95% CI: 1.10–2.27), mistimed pregnancy (aOR 1.44, 95% CI: 1.05–1.98), low level of social support (aOR 1.69, 95% CI: 1.05–2.73), good health (aOR 1.88, 95% CI: 1.43–2.47), postpartum depression symptoms (aOR 1.55, 95% CI: 1.02–2.37) and a self-reported ‘too-short’ postpartum hospital stay (aOR 1.69, 95% CI: 1.21–2.35). Additionally, accessing care for an infant with a birth weight of 2500 g or more (aOR 2.43, 95% CI: 1.02–5.82), was associated with reporting difficulty. Household income, mothers’ level of education, marital status, Aboriginal ethnicity, and size of community of residence were not associated with difficulty accessing care.

Conclusions

Ease of health care access for Canadian infants is not equal, suggesting that efforts to improve access should be tailored to groups facing increased difficulties.

Nutrition for Multiples

In 2012 there were 135,943 infants of multiple pregnancies born in the United States, nearly a 2-fold increase since 1980, with twins accounting for 96% of all multiple births. To date, most perinatal morbidities associated with multiple births have proven resistant to technological or pharmaceutical interventions. Maternal nutrition can have a profound effect on the course and outcome of multiple pregnancy, with the goal of achieving optimal intrauterine growth and birthweights, and minimizing prenatal and perinatal complications for the mother and her children.

Effects of protein energy supplementation during pregnancy on fetal growth: a review of the literature focusing on contextual factors

Background

Maternal diet during pregnancy is one of the most important factors associated with adequate fetal growth. There are many complications associated with fetal growth restriction that lead to lifelong effects. The aim of this review was to describe the studies examining the effects of protein energy supplementation during pregnancy on fetal growth focusing on the contextual differences.

Methods

Relevant articles published between 2007 and 2012 were identified through systematic electronic searches of the PubMed, Science Direct, and EBSCO database and the examination of the bibliographies of retrieved articles. The search aimed to identify studies examining pregnant women receiving protein and/or energy during pregnancy and to assess fetal growth measures. Data of effectiveness and practical aspects of protein energy supplementation during pregnancy were extracted and compiled.

Results

Twenty studies (11 randomized controlled trials, 8 controlled before and after, and 1 prospective study) were included in this review. Positive outcomes in infants and women cannot be expected if the supplementation is not needed. Therefore, it is essential to correctly select women who will benefit from dietary intervention programs during pregnancy. However, there is currently no consensus on the most effective method of identifying these women. The content of protein in the supplements considering total diet is also an important determinant of fetal growth. Balanced protein energy supplementation (containing up to 20% of energy as protein) given to pregnant women with energy or protein deficit appears to improve fetal growth, increase birth weight (by 95–324 g) and height (by 4.6–6.1 mm), and decrease the percentage of low birth weight (by 6%). Supplements with excess protein (>20% of energy as protein) provided to women with a diet already containing adequate protein may conversely impair fetal growth. There is also no consensus on the best time to start supplementation.

Conclusions

Strong quality studies examining adequate criteria to screen women who would benefit from supplementation, time to start supplementation, and type of supplements are warranted.

Medicaid expansion initiative in Massachusetts: enrollment among substance-abusing homeless adults

OBJECTIVES

We assessed whether homeless adults entering substance abuse treatment in Massachusetts were less likely than others to enroll in Medicaid after implementation of the MassHealth Medicaid expansion program in 1997.

METHODS

We used interrupted time-series analysis in data on substance abuse treatment admissions from the Treatment 0Episode Data Set (1992-2009) to evaluate Medicaid coverage rates in Massachusetts and to identify whether trends differed between homeless and housed participants. We also compared Massachusetts data with data from 17 other states and the District of Columbia combined.

RESULTS

The percentage of both homeless and housed people entering treatment with Medicaid increased approximately 21% after expansion (P = .01), with an average increase of 5.4% per year over 12 years (P = .01). The increase in coverage was specific to Massachusetts, providing evidence that the MassHealth policy was the cause of this increase.

CONCLUSIONS

Findings provide evidence in favor of state participation in the Medicaid expansion in January 2014 under the Affordable Care Act and suggest that hard-to-reach vulnerable groups such as substance-abusing homeless adults are as likely as other population groups to benefit from this policy.

The effect of the WIC program on the health of newborns

OBJECTIVE

To determine the effect of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) on birth outcomes.

DATA SOURCE

The Child Development Supplement (CDS) of the Panel Study of Income Dynamics (PSID). The PSID provides extensive data on the income and well-being of a representative sample of U.S. families from 1968 to present. The CDS collects information on the children in PSID families ranging from cognitive, behavioral, and health status to their family and neighborhood environment. The first two waves of the CDS were conducted in 1997 and 2002, respectively. We use information on 3,181 children and their mothers.

STUDY DESIGN

We use propensity score matching with multiple imputations to examine whether WIC program influences birth outcomes: birth weight, prematurity, maternal report of the infant's health, small for gestational age, and placement in the neonatal intensive care unit. Furthermore, we use a fixed-effects model to examine the above outcomes controlling for mother-specific unobservables.

PRINCIPAL FINDINGS

After using propensity scores to adjust for confounding factors, WIC shows no statistically significant effects for any of six outcomes. Fixed-effects models, however, reveal some effects that are statistically significant and fairly substantial in size. These involve preterm birth and birth weight.

CONCLUSIONS

Overall, the WIC program had moderate effects, but findings were sensitive to the estimation method used.

The effect of racial residential segregation on black infant mortality

Economic differences and proximal risk factors do not fully explain the persistent high infant mortality rates of African Americans (blacks). The authors hypothesized that racial residential segregation plays an independent role in high black infant mortality rates. Segregation restricts social and economic advantage and imposes negative environmental exposures that black women and infants experience. The study sample was obtained from the 2000-2002 US Linked Birth/Infant Death records and included 677,777 black infants residing in 64 cities with 250,000 or more residents. Outcomes were rates of all-cause infant mortality, postneonatal mortality, and external causes of death. Segregation was measured by using the isolation index (dichotomized at 0.60) from the 2000 US Census Housing Patterns. Propensity score matching methods were used. After matching on propensity scores, no independent effect of segregation on black infant mortality rates was found. Results show little statistical evidence that segregation plays an independent role in black infant mortality. However, a key finding is that it is difficult to disentangle contextual effects from the characteristics of individuals.

Infant mortality in the Lower Mississippi Delta: geography, poverty and race

OBJECTIVE

The objectives of this study were to explore regional, economic and racial disparities in infant mortality rates between geographic sub-regions within the eight states containing the Delta and to test hypotheses that regional disparities would decrease over time while county poverty level and racial composition would remain significant predictors of infant mortality rates.

STUDY DESIGN

The study used secondary data analysis of county level rates, including descriptive statistics, hierarchical multiple regression with interaction effects and linear multiple regression. Models testing the impact of sub-regional geographic differences, percent of poverty, percent of black population and interaction effects were conducted at three time periods, the late 1970s, late 1980s and late 1990s.

RESULTS

In the first time period, regional differences, percent of poverty, percent of black population and the interaction of region and poverty were all predictive of infant mortality (R(2) = 0.31, P < 0.0001). In the subsequent time periods, only percent of poverty and percent of black population were significant predictors (R(2) = 0.20, P < 0.0001 and R(2) = 0.26, P < 0.0001).

CONCLUSIONS

During the late 1970s and early 1980s, region, poverty and racial composition of counties all played an important part in predicting life chances for infants born in these eight states. Furthermore, Central Delta infants in counties with poverty levels of 30% or greater were significantly more likely to die than infants in other areas with the same rates of poverty, even after controlling for racial composition. The impact of regional differences was no longer significant at the ends of the subsequent two decades. Both medical and policy changes during these decades may have contributed to the decreased impact of region. However, both poverty and racial composition continue as important factors, accounting for more variance in the late 1990s than a decade before.

Racial and ethnic differences in general health status and limiting health conditions among American children: parental reports in the 1999 national survey of America's families

OBJECTIVES

This research investigates the association between race/ethnicity and child health, and examines the role of family structure, family socioeconomic status (SES), and healthcare factors in this association. Five major racial/ethnic groups in the US are studied. Two child health outcomes, including parent-rated health and limiting health condition, are examined. The analysis is stratified into three age groups: age 0-5, age 6-11, and age 12-17.

DESIGN

Cross-sectional study using data from a large, nationally representative sample collected in 1999 in the US.

RESULTS

Older age groups tend to exhibit larger racial/ethnic disparities in child health. Except for some age groups of Asian youths, minority children and adolescents generally show higher risks of fair or poor parent-rated health and limiting health condition relative to Whites. Family SES partly explains the effects of Black, Hispanic, and Native American groups, but significant amount of residual effects remain. Family structure explains some Black effects, but not for other minority groups. Healthcare factors do not contribute much to the racial/ethnic differences. Both family structure and healthcare factors are important factors of child health in their own right. None of the social factors examined can explain the effects of the Asian group. Data also show that economic resources play a more salient role in child health than parental education, especially in young children. In addition, healthcare factors, to some extent, can explain why children from higher SES families fare better in health.

CONCLUSION

Racial/ethnic disparities in health start early in life. Except for Asians, class explains a substantial amount, but not all, of these disparities. Healthcare factors play some role in explaining health disparities by class. Structural solution seems to be needed to reduce disparities by race/ethnicity among youths.

Health insurance and access to health care in the United States

Health insurance, poverty, and health are all interconnected in the United States. This article synthesizes a large and compelling body of health services research, finding a strong association between health insurance coverage and access to primary and preventive care, the treatment of acute and traumatic conditions, and the medical management of chronic illness. Moreover, by improving access to care, health insurance coverage is also fundamentally important to better health care and health outcomes. Research connects being uninsured with adverse health outcomes, including declines in health and function, preventable health problems, severe disease at the time of diagnosis, and premature mortality.

Son preference, use of maternal health care, and infant mortality in rural China, 1989-2000

This study assesses the effects of socio-economic conditions and the interaction between son preference and China's one-child family planning policy on the use of maternal health care services and their effects on infant mortality in rural China, using nationally representative data from the 2001 National Family Planning and Reproductive Health Survey. The results show that while the use of maternal health care services has continued to increase over time, large gaps still exist in the use of these services and in infant survival by mother's education, community income, and parity. Further improvements in the reproductive health of all women and in infant survival will require effective reduction of the obstacles to the use of maternal health care among those women in rural China who are less educated, poor, and of higher parity.

The role of community health centers in delivering primary care to the underserved: experiences of the uninsured and Medicaid insured

Community health centers (CHCs) have long served an important safety-net healthcare delivery role for vulnerable populations. Federal efforts to expand CHCs, while potentially reducing the Federal budget for Medicaid, raise concern about how Medicaid and uninsured patients of CHCs will continue to fare. To examine the primary care experiences of uninsured and Medicaid CHC patients and compare their experiences with those of similar patients nationally, cross-sectional analyses of the 2002 CHC User Survey with comparison data from the 1998 and 2002 National Health Interview surveys were done. Self-reported measures of primary care access, longitudinality, and comprehensiveness of care among adults aged 18 to 64 years were used. Despite poorer health, CHCs were positively associated with better primary care experiences in comparison with similar patients nationally. Uninsured CHC patients were more likely than similar patients nationally to report a generalist physician visit in the past year (82% vs 68%, P < .001), having a regular source of care (96% vs 60%, P < .001), receiving a mammogram in the past 2 years (69% vs 49%, P < .001), and receiving counseling on exercise (68% vs 48%, P < .001). Similar results were found for CHC Medicaid patients versus Medicaid patients nationally. Even within CHCs, however, Medicaid patients tended to report better primary care experiences than the uninsured. Health centers appear to fill an important gap in primary care for Medicaid and uninsured patients. Nonetheless, this study suggests that Medicaid insurance remains fundamental to accessing high-quality primary care, even within CHCs.

Socioeconomic factors and adolescent pregnancy outcomes: distinctions between neonatal and post-neonatal deaths?

BACKGROUND

Young maternal age has long been associated with higher infant mortality rates, but the role of socioeconomic factors in this association has been controversial. We sought to investigate the relationships between infant mortality (distinguishing neonatal from post-neonatal deaths), socioeconomic status and maternal age in a large, retrospective cohort study.

METHODS

We conducted a population-based cohort study using linked birth-death certificate data for Missouri residents during 1997-1999. Infant mortality rates for all singleton births to adolescent women (12-17 years, n = 10,131; 18-19 years, n = 18,954) were compared to those for older women (20-35 years, n = 28,899). Logistic regression was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for all potential associations.

RESULTS

The risk of infant (OR 1.95, CI 1.54-2.48), neonatal (1.69, 1.24-2.31) and post-neonatal mortality (2.47, 1.70-3.59) were significantly higher for younger adolescent (12-17 years) than older (20-34 years) mothers. After adjusting for race, marital status, age-appropriate education level, parity, smoking status, prenatal care utilization, and poverty status (indicated by participation in WIC, food stamps or Medicaid), the risk of post-neonatal mortality (1.73, 1.14-2.64) but not neonatal mortality (1.43, 0.98-2.08) remained significant for younger adolescent mothers. There were no differences in neonatal or post-neonatal mortality risks for older adolescent (18-19 years) mothers.

CONCLUSION

Socioeconomic factors may largely explain the increased neonatal mortality risk among younger adolescent mothers but not the increase in post-neonatal mortality risk.

Nutrition in multiple gestations

Multiple pregnancies represent a state of magnified nutritional requirements, resulting in a greater nutrient drain on maternal resources and an accelerated depletion of nutritional reserves. Maternal weight gain to 20 weeks and between 20 and 28 weeks has the greatest effect on birthweight in twin and triplet pregnancies, particularly among underweight women. Parity, which most likely represents a higher proportion of body fat, has a positive effect on pregnancy outcome, with an average 7 to 10 days longer gestation for multiparous versus nulliparous women. In addition to being the nutrients most often lacking in a woman's diet, calcium, magnesium, and zinc have been identified as having the most potential for reducing pregnancy complications and improving outcomes.

Does WIC work? The effects of WIC on pregnancy and birth outcomes

Support for WIC, the Special Supplemental Nutrition Program for Women, Infants, and Children, is based on the belief that "WIC works." This consensus has lately been questioned by researchers who point out that most WIC research fails to properly control for selection into the program. This paper evaluates the selection problem using rich data from the national Pregnancy Risk Assessment Monitoring System. We show that relative to Medicaid mothers, all of whom are eligible for WIC, WIC participants are negatively selected on a wide array of observable dimensions, and yet WIC participation is associated with improved birth outcomes, even after controlling for observables and for a full set of state-year interactions intended to capture unobservables that vary at the state-year level. The positive impacts of WIC are larger among subsets of even more disadvantaged women, such as those who received public assistance last year, single high school dropouts, and teen mothers.

America's Health Centers: reducing racial and ethnic disparities in perinatal care and birth outcomes

OBJECTIVE

To examine whether community health centers (CHCs) reduce racial/ethnic disparities in perinatal care and birth outcomes, and to identify CHC characteristics associated with better outcomes.

BACKGROUND

Despite great national wealth, the U.S. continues to rank poorly relative to other industrialized nations on infant mortality and other birth outcomes, and with wide inequities by race/ethnicity. Disparities in primary care (including perinatal care) may contribute to disparities in birth outcomes, which may be addressed by CHCs that provide safety-net medical services to vulnerable populations.

METHODS

Data are from annual Uniform Data System reports submitted to the Bureau of Primary Health Care over six years (1996-2001) by about 700 CHCs each year.

RESULTS

Across all years, about 60% of CHC mothers received first-trimester prenatal care and more than 70% received postpartum and newborn care. In 2001, Asian mothers were the most likely to receive both postpartum and newborn care (81.7% and 80.3%), followed by Hispanics (75.0% and 76.3%), blacks (70.8% and 69.9%), and whites (70.7% and 66.7%). In 2001, blacks had higher rates of low birth weight (LBW) babies (10.4%), but the disparity in rates for blacks and whites was smaller in CHCs (3.3 percentage points) compared to national disparities for low-socioeconomic status mothers (5.8 percentage points) and the total population (6.2 percentage points). In CHCs, greater perinatal care capacity was associated with higher rates of first-trimester prenatal care, which was associated with a lower LBW rate.

CONCLUSION

Racial/ethnic disparities in certain prenatal services and birth outcomes may be lower in CHCs compared to the general population, despite serving higher-risk groups. Within CHCs, increasing first-trimester prenatal care use through perinatal care capacity may lead to further improvement in birth outcomes for the underserved.

The increasing racial disparity in infant mortality: Respiratory distress syndrome and other causes

Although substantial declines in infant mortality rates have occurred across racial/ethnic groups, there has been a marked increase in relative black-white disparity in the risk of infant death over the past two decades. The objective of our analysis was to gain insight into the reasons for this growing inequality on the basis of data from linked cohort files for 1989–1990 and 1995–1998. We found a nationwide reversal from a survival advantage to a survival disadvantage for blacks with respect to respiratory distress syndrome over this period. The results are consistent with the view that the potential for a widening of the relative racial gap in infant mortality is high when innovations in health care occur in a continuing context of social inequality. As expected, the results for other causes of infant mortality, although similar, are less striking. Models of absolute change demonstrate that among low-weight births, absolute declines in mortality were greater for white infants than for black infants.

WIC participation, breastfeeding practices, and well-child care among unmarried, low-income mothers

We estimated the effect of Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) participation in 1999 to 2000 on breastfeeding initiation and duration and well-child care. We applied multivariate regression to a sample of 2136 unmarried, low-income, urban mothers from the Fragile Families and Child Wellbeing Study. WIC participation was associated with small increases in the probabilities of initiating breastfeeding and having had at least 4 well-child visits since birth-behaviors that benefit infants beyond the newborn period-but not with breastfeeding duration.

Early origins of the gradient: the relationship between socioeconomic status and infant mortality in the United States

Although relationships between social conditions and health have been documented for centuries, the past few decades have witnessed the emergence of socioeconomic gradients in health and mortality in most developed countries. These gradients indicate that health improves, although decreasingly so, at higher levels of socioeconomic status. To minimize problems with reverse causality, I tested competing hypotheses for observed socioeconomic gradients for infant mortality outcomes. I found no support for the income-inequality hypothesis and negligible support for the occupational-grade hypothesis. The results indicate that absolute material conditions are the most important determinants of socioeconomic effects on the risk of infant mortality and that while poverty has the most pronounced effect on risk, income is decreasingly salutary across the majority of the mortality gradient.

Socioeconomic gradients and low birth-weight: empirical and policy considerations

OBJECTIVE

To examine whether socioeconomic status (SES) gradients emerge in health outcomes as early as birth and to examine the magnitude, potential sources, and explanations of any observed SES gradients.

DATA SOURCES

The National Maternal and Infant Health Survey conducted in 1988.

STUDY DESIGN

A multinomial logistic regression of trichotomized birth-weight categories was conducted for normal birth-weight (2,500-5,500 grams), low birth-weight (LBWT; < 2,500 grams), and heavy birth-weight (> 5,500 grams). Key variables included income, education, occupational grade, state-level income inequality, and length of participation in Women-Infants-Children (WIC) for pregnant mothers.

PRINCIPAL FINDINGS

A socioeconomic gradient for low birth-weight was discovered for an adjusted household income measure, net of all covariates in the unrestricted models. A gross effect of maternal education was explained by maternal smoking behaviors, while no effect of occupational grade was observed, net of household income. There were no significant state-level income inequality effects (Gini coefficient) for any of the models. In addition, participation in WIC was discovered to substantially flatten income gradients for short-term participants and virtually eliminate an income gradient among long-term participants.

CONCLUSIONS

Although a materialist explanation for early-life SES gradients seems the most plausible (vis-à-vis psychosocial and occupational explanations), more research is needed to discover potential interventions. In addition, the notion of a monotonic gradient in which income is salutary across the full range of the distribution is challenged by these data such that income may cease to be beneficial after a given threshold. Finally, the success of WIC participation in flattening SES gradients argues for either: (a) the experimental efficacy of WIC, or (b) the biasing selection characteristics of WIC participants; either conclusion suggests that interventions or characteristics of participants deserves further study as a potential remedy for socioeconomic disparities in early-life health outcomes such as LBWT.

Infant mortality and family welfare: policy implications for Indonesia

STUDY OBJECTIVE

To examine the effect of family welfare index (FWI) and maternal education on the probability of infant death.

DESIGN

A population based multistage stratified clustered survey.

SETTING

Women of reproductive age in Indonesia between 1983-1997.

DATA SOURCES

The 1997 Indonesian Demographic and Health Survey.

MAIN RESULTS

Infant mortality was associated with FWI and maternal education. Relative to families of high FWI, the risk of infant death was almost twice among families of low FWI (aOR=1.7, 95%CI=0.9 to 3.3), and three times for families of medium FWI (aOR=3.3,95%CI=1.7 to 6.5). Also, the risk of infant death was threefold higher (aOR=3.4, 95% CI=1.6 to 7.1) among mothers who had fewer than seven years of formal education compared with mothers with more than seven years of education. Fertility related indicators such as young maternal age, absence from contraception, birth intervals, and prenatal care, seem to exert significant effect on the increased probability of infant death.

CONCLUSIONS

The increased probability of infant mortality attributable to family income inequality and low maternal education seems to work through pathways of material deprivation and chronic psychological stress that affect a person's health damaging behaviours. The policies that are likely to significantly reduce the family's socioeconomic inequality in infant mortality are implicated.

Effects of low income on infant health

BACKGROUND

Few population-based studies have analyzed the link between poverty and infant morbidity. In this study, we wanted to determine whether inadequate income itself has an impact on infant health.

METHODS

We interviewed 2223 mothers of 5-month-old children participating in the 1998 phase of the Quebec Longitudinal Study of Child Development to determine their infant's health and the sociodemographic characteristics of the household (including household income, breast-feeding and the smoking habits of the mother). Data on the health of the infants at birth were taken from medical records. We examined the effects of household income using Statistics Canada definitions of sufficient (above the low-income threshold), moderately inadequate (between 60% and 99% of the low-income threshold) and inadequate (below 60% of the low-income threshold) income on the mother's assessment of her child's overall health, her report of her infant's chronic health problems and her report of the number of times, if any, her child had been admitted to hospital since birth. In the analysis, we controlled for factors known to affect infant health: infant characteristics and neonatal health problems, the mother's level of education, the presence or absence of a partner, the duration of breast-feeding and the mother's smoking status.

RESULTS

Compared with infants in households with sufficient incomes, those in households with lower incomes were more likely to be judged by their mothers to be in less than excellent health (moderately inadequate incomes: adjusted odds ratio [OR] 1.5, 95% confidence interval [CI] 1.1-2.1; very inadequate incomes: adjusted OR 1.8, 95% CI 1.3-2.6). Infants in households with moderately inadequate incomes were more likely to have been admitted to hospital (adjusted OR 1.8, 95% CI 1.2-2.6) than those in households with sufficient incomes, but the same was not true of infants in households with very inadequate incomes (adjusted OR 0.7, 95% CI 0.4-1.2). Household income did not significantly affect the likelihood of an infant having chronic health problems.

INTERPRETATION

Less than sufficient household incomes are associated with poorer overall health and higher hospital admission rates among infants in the first 5 months of life, even after adjustment for factors known to affect infant health, including the mother's level of education.

Research, policy, and the federal role in prevention initiatives for children

With the ability and the funds to implement programs on a national level, federal policy is a potentially potent tool in primary prevention. Despite the U.S. government's history of ambivalence toward intervening in child rearing and limited national support for primary prevention, several initiatives have been implemented for children and families with some measure of success. The successes, however, are mitigated by limitations of the initiatives themselves and by the inconclusive nature of much of the evaluation data. This review of 5 federal policy-based initiatives for children and families provides the backdrop for discussing aspects of federal prevention program design, implementation, policy, and research.

Sicker and poorer--the consequences of being uninsured: a review of the research on the relationship between health insurance, medical care use, health, work, and income

Health services research conducted over the past 25 years makes a compelling case that having health insurance or using more medical care would improve the health of the uninsured. The literature's broad range of conditions, populations, and methods makes it difficult to derive a precise quantitative estimate of the effect of having health insurance on the uninsured's health. Some mortality studies imply that a 4% to 5% reduction in the uninsured's mortality is a lower bound; other studies suggest that the reductions could be as high as 20% to 25%. Although all of the studies reviewed suffer from methodological flaws of varying degrees, there is substantial qualitative consistency across studies of different medical conditions conducted at different times and using different data sets and statistical methods. Corroborating process studies find that the uninsured receive fewer preventive and diagnostic services, tend to be more severely ill when diagnosed, and receive less therapeutic care. Other literature suggests that improving health status from fair or poor to very good or excellent would increase both work effort and annual earnings by approximately 15% to 20%.

Why do WIC participants fail to pick up their checks? An urban study in the wake of welfare reform

OBJECTIVES

This study explored whether work or immigration concerns affect women's participation in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

METHODS

The sample included women who had withdrawn from the WIC program and current WIC clients from 1 center in New York City. Logistic regression analyses were used to predict noncollection of checks; demographic characteristics, program participation, and problems with the WIC program were independent variables.

RESULTS

Strong predictors of noncollection of checks were job conflicts, transportation or illness problems, and WIC receipt by the woman herself (rather than by her children).

CONCLUSIONS

Employment conflicts were related to failure to pick up WIC checks; immigration concerns were not. As a means of enhancing WIC participation, flexibility is recommended in terms of center hours, locations, and staffing and program check distribution policies.

Structure, process, and satisfaction with obstetricians: an analysis of mainland Puerto Ricans

This study examines various dimensions of satisfaction with obstetricians among mainland Puerto Ricans using data from a survey administered to a representative sample of 1,219 Puerto Rican mothers. The results indicate that the majority of Puerto Rican women are satisfied with their obstetricians, but they are not typically "extremely" satisfied. Moreover, satisfaction is influenced by the structure of care, the process of care, and the outcome of care. Two aspects of process that are especially important are the continuity and content of care. Although satisfaction is not generally associated with the ethnicity or the gender of physicians, some evidence suggests that patients who utilize public facilities or lack continuity of care tend to be more satisfied if they have a female physician.

Poverty, prenatal care, and infant health in Puerto Rico

Using data from a survey administered to a representative sample of mothers who gave birth in Puerto Rico in 1994-95, we investigate whether prenatal care and infant health outcomes are associated with family poverty and neighborhood poverty. The results show that infant health outcomes are unrelated to both family poverty and neighborhood poverty, despite the association of family poverty with the adequacy of prenatal care and the content of prenatal care. However, the poverty paradigm does receive some support using measures of participation in government programs that serve the low-income population. Women who rely on the government to fund their medical care are more likely than women who rely on private health insurance to have an infant death. They are also less likely to receive the highest levels of prenatal care. Nonetheless, targeted government programs can have an ameliorative impact. The analysis shows that participants in the Women, Infants, and Children (WIC) program are more likely than non-participants to receive superior levels of prenatal care and are less likely to have negative infant health outcomes.

Racial/ethnic disparities in infant mortality: the role of behavioral factors

Using the National Maternal and Infant Health Survey 1988 (NMIHS), a nationally representative sample of mothers, we investigate the role of behavioral factors in explaining racial/ethnic disparities in infant mortality. In particular, we focus on the following variables: weight gain during pregnancy, prenatal care utilization, exercise, vitamin use, and substance use during pregnancy. These analyses are conducted by modeling both time of death (neonatal vs. postneonatal) and cause of death (infections, perinatal complications, delivery complications, congenital malformations, SIDS, other causes) outcomes. Our results suggest that behavioral factors are partially responsible for observed race/ethnic differentials in infant mortality, but are not as important as sociostructural determinants such as SES.

Maternal nutrition and perinatal survival

The simple relationship between maternal macronutrient status and perinatal survival (increased macronutrient intake --> increased maternal weight and/or weight gain --> increased fetal growth --> improved survival) that is usually posited is no longer defensible. First, maternal weight and weight gain are remarkably resistant to either dietary advice or supplementation; further, increased birth weight attributable to maternal nutrition does not necessarily increase perinatal survival (because prepregnant weight is positively associated with both birth weight and higher perinatal mortality). Finally, whereas dietary supplements during pregnancy may have a modest effect on birth weight in nonfamine conditions (by contrast with a large effect in famine or near-famine conditions), their impact is not mediated by maternal energy deposition. Rather, the component of maternal weight gain associated with accelerated fetal growth is maternal water (presumably plasma) volume.

A randomized trial of nurse specialist home care for women with high-risk pregnancies: outcomes and costs

OBJECTIVE

To examine prenatal, maternal, and infant outcomes and costs through 1 year after delivery using a model of prenatal care for women at high risk of delivering low-birth-weight infants in which half of the prenatal care was provided in women's homes by nurse specialists with master's degrees.

STUDY DESIGN

Randomized clinical trial.

PATIENTS AND METHODS

A sample of 173 women (and 194 infants) with high-risk pregnancies (gestational or pregestational diabetes mellitus, chronic hypertension, preterm labor, or high risk of preterm labor) were randomly assigned to the intervention group (85 women and 94 infants) or the control group (88 women and 100 infants). Control women received usual prenatal care. Intervention women received half of their prenatal care in their homes, with teaching, counseling, telephone outreach, daily telephone availability, and a postpartum home visit by nurse specialists with physician backup.

RESULTS

For the full sample, mean maternal age was 27 years; 85.5% of women were single mothers, 36.4% had less than a high school education, 93.6% were African American, and 93.6% had public health insurance, with no differences between groups on these variables. The intervention group had lower fetal/infant mortality vs the control group (2 vs 9), 11 fewer preterm infants, more twin pregnancies carried to term (77.7% vs 33.3%), fewer prenatal hospitalizations (41 vs 49), fewer infant rehospitalizations (18 vs 24), and a savings of more than 750 total hospital days and $2,496,145 [corrected].

CONCLUSION

This model of care provides a reasoned solution to improving pregnancy and infant outcomes while reducing healthcare costs.

Prenatal care utilization among non-Hispanic Whites, African Americans, and Mexican Americans

OBJECTIVES

The general objective of this study is to explain differentials in prenatal care (PNC) utilization in a nationally representative sample of non-Hispanic White (Anglo), African American, and Mexican American women.

METHOD

The analysis is based on the National Maternal and Infant Health Survey. Multivariate, multinomial logistic regression models were employed to adjust for demographic, socioeconomic, medical risk, and program participation factors, as well as for perceived barriers. Both race/ethnic-specific models and models with race/ethnicity as a covariate were estimated.

RESULTS

Inadequate PNC use was much less common among Anglos (10.4%) as compared to African Americans and Mexican Americans (22.1% and 25.0%, respectively). In fully adjusted models, the odds ratio (OR) of African Americans receiving inadequate PNC was 1.46, while the risk for Mexican Americans was greater (OR = 1.93). Perception of obstacles to PNC access doubled the odds of receiving inadequate care, but this psychosocial variable had little impact on race/ethnic differentials. Race/ethnic-specific models uncovered potentially important racial/ethnic variations associated with perception of barriers, marital status, and program participation.

CONCLUSIONS

Although the same risk factors sometimes have different effects across race/ethnic groups, and while certain findings indicate a beneficial impact of health outreach efforts and program participation, our findings support the conclusion that PNC utilization continues to be stratified along race/ethnic lines.

The key to the door: Medicaid's role in improving health care for women and children

Medicaid is the nation's major public financing program for providing health insurance coverage and long-term care services to the poor. This article assesses Medicaid's contributions over the last three decades to improving the coverage, access to care, and health of low-income children and women. The article reviews Medicaid's impact on the low-income population covered by this program, demonstrating both the role insurance plays and its limitations as a strategy for improving the health of vulnerable populations. Medicaid has shown over the last three decades that it is an important lever to help open the door to better health care, and ultimately to improved health for America's poor women and children, by substantially expanding coverage of the low-income population and helping to reduce differentials in access to care between the poor and the privately insured. Gaps in coverage and limitations in access persist, but overall the program has resulted in better coverage, access, and health care for millions of poor children and their parents.