Chip Shots: Association Between the State Children's Health Insurance Programs and Immunization Coverage and Delivery

By age two a child who is up to date for immunizations will have received up to 19 shots delivered over eight visits at a market cost of $525 dollars for the vaccines alone, a far more expensive and demanding regimen that the 8 shots received in 1987. In recognition of the potential importance of health insurance to immunization coverage rates, the State Children's Health Insurance Program (SCHIP) mandated that all plans cover the cost and administration of childhood vaccines. We use data from the recently released National Immunization Survey for the years 1995 to 2001 to test whether SCHIP was associated with differential changes among poor and near-poor children relative to their non-poor counterparts in either age-appropriate immunization rates or in the proportion of vaccines delivered by private providers. We show that the probability that a child was up to date for the varicella vaccine increased between 7 and 16 percentage points more among poor and near-poor relative to non-poor children after implementation of SCHIP. The increase was greater among children from urban areas, among Hispanics and among those from states with the highest rates of uninsured children prior to SCHIP than among children nationally. We found small to inconsequential changes for other vaccines. We also found that the probability that a poor or near-poor child obtained all vaccines at a private provider fell relative to the same probability among non-poor children over the study period. SCHIP appears to have affected the uptake of a recently introduced vaccine, which suggests that insurance coverage may be important for the rapid adoption of the latest and increasingly more expensive agents such as the pneumococcal conjugate vaccine.

Reassessing the WIC Effect: Evidence from the Pregnancy Nutrition Surveillance System

Recent analyses differ on how effective the Special Supplemental Nutrition Program for Women, Infants and Children (WIC) is at improving infant health. We use data from nine states that participate in the Pregnancy Nutrition Surveillance System to address limitations in previous work. With information on the mother's timing of WIC enrollment, we test whether greater exposure to WIC is associated with less smoking, improved weight gain during pregnancy, better birth outcomes, and greater likelihood of breastfeeding. Our results suggest that much of the often-reported association between WIC and lower rates of preterm birth is likely spurious, the result of gestational age bias. We find modest effects of WIC on fetal growth, inconsistent associations between WIC and smoking, limited associations with gestational weight gain, and some relationship with breast feeding. A WIC effect exists, but on fewer margins and with less impact than has been claimed by policy analysts and advocates.

Does Publicly Provided Health Insurance Improve the Health of Low-Income Children in the United States

In this study we analyze the effect of Medicaid on children's heath. We examine the effect of Medicaid on a variety of health outcomes using two data sources: the National Health Interview Surveys (NHIS) and the Nationwide Inpatient Sample (NIS) of hospital discharges. Using the NHIS, we examine the effect of Medicaid participation on maternal ratings of child health and maternal reports of the number of bed days in the past year (i.e. morbidity). The NIS data was used to examine the effect of Medicaid program expansions on the incidence of ambulatory care sensitive (ACS) discharges. ACS discharges are known to be sensitive to medical intervention and are objective measures of children's health. The results of this paper provide at best weak support for the hypothesis that Medicaid improves the health of low-income children.

The Impact of Prenatal Exposure to Cocaine on Newborn Costs and Length of Stay

This paper determines newborn costs and lengths of stay attributable to prenatal exposure to cocaine and other illicit drugs, using as a data source all parturients who delivered at a large municipal hospital in New York City between November 18, 1991 and April 11, 1992. We performed a cross-sectional analysis in which multivariate, loglinear regressions were used to analyze differences in costs and length of stay between infants exposed and unexposed prenatally to cocaine and other illicit drugs adjusting for maternal race, age, prenatal care, tobacco, parity, type of delivery, birth weight, prematurity, and newborn infection. Urine specimens, with linked obstetric sheets and discharge abstracts provided information on exposure, prenatal behaviors, costs, length of stay and discharge disposition. Our principal findings show that infants exposed to cocaine and some other illicit drug stay approximately 7 days longer at a cost of $7,731 more than infants unexposed. Approximately 60 percent of these costs are indirect, the result of adverse birth outcomes and newborn infection. Hospital screening as recorded on discharge abstracts substantially underestimates prevalence at delivery, but overestimates its impact on costs.

Differential Impact of Recent Medicaid Expansions by Race and Ethnicity

Objective. Between 1989 and 1995, expansions in Medicaid eligibility provided publicly financed health insurance to an additional 7 million poor and near-poor children. It is not known whether these expansions affected children’s insurance coverage, use of health care services, or health status differently, depending on their race/ethnicity. The objective of this study was to examine, by race/ethnicity, the impact of the recent Medicaid expansions on levels of uninsured individuals, health care service utilization, and health status of the targeted groups of children. Methods. Using a stratified set of longitudinal data from the National Health Interview Surveys of 1989 and 1995, we compared changes in measures of health insurance coverage, health services utilization, and health status for poor white, black, and Hispanic 1- to 12-year-old children. To control for underlying trends over time, we subtracted 1989 to 1995 changes in these outcomes among nonpoor children from changes among the poor children for each race/ethnicity group. Measures of coverage included uninsured rates and Medicaid rates. Utilization measures included annual probability of visiting a doctor, annual number of doctor visits, and annual probability of hospitalization. Health status measures included self-reported health status and number of restricted-activity days in the 2 weeks before the interview. Differences in means were analyzed with the use of Student’s t tests accounting for the clustering sample design of the National Health Interview Surveys. Results. Among poor children between 1989 and 1995, uninsured rates declined by 4 percentage points for whites, 11 percentage points for blacks, and 19 percentage points for Hispanics. Medicaid rates for these groups increased by 16 percentage points, 22 percentage points, and 23 percentage points, respectively. With respect to utilization, the annual probability of seeing a physician increased 7 percentage points among poor blacks and Hispanics but only 1 percentage point among poor whites (not significant) for children in good, fair, or poor health. Among those in excellent or very good health, the respective increases were 1 percentage point for poor whites (not significant), 7 percentage points for poor blacks, and 3 percentage points for poor Hispanics (not significant). Significant increases in numbers of doctor visits per year were recorded only for poor Hispanics who were in excellent or very good health, whereas significant decreases in hospitalizations were recorded for Hispanics who were in good fair or poor health. Measures of health status remained unchanged for poor children over time. The recorded decreases in uninsured rates and increases in Medicaid coverage remained robust to adjustments for underlying trends for all 3 race/ethnicity groups. With respect to adjusted measures of utilization and health status, the only significant differences found were among poor blacks who were in good, fair, or poor health and who registered increases in the likelihood of hospitalization and in poor Hispanics who were in excellent or very good health and who registered decreases in the numbers of restricted-activity days. Conclusions. Recent expansions in the Medicaid program from 1989 to 1995 produced greater reductions in uninsured rates among poor minority children than among poor white children. Regardless of race/ethnicity, poor children did not seem to experience significant changes during the period of the expansions in either their level of health service utilization or their health status. Reproduced with permission from Pediatrics, Copyright (c) 2001 by the AAP

Maternal Smoking and the Timing of WIC Enrollment

We investigate the association between the timing of enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) and smoking among prenatal WIC participants. We use WIC data from eight states participating in the Pregnancy Nutrition Surveillance System (PNSS). Women who enroll in WIC in the first trimester of pregnancy are 2.7 percentage points more likely to be smoking at intake than women who enroll in the third trimester. Among participants who smoked before pregnancy and at prenatal WIC enrollment, those who enrolled in the first trimester are 4.5 percentage points more likely to quit smoking 3 months before delivery and 3.4 percentage points more likely to quit by postpartum registration, compared with women who do not enroll in WIC until the third trimester. Overall, early WIC enrollment is associated with higher quit rates, although changes are modest when compared to the results from smoking cessation interventions for pregnant women.

Effect of Telephone Calls From Primary Care Practices on Follow-up Visits After Pediatric Emergency Department Visits Evidence From the Pediatric Emergency Department Links to Primary Care (PEDLPC) Randomized Controlled Trial

Objective: To test whether follow-up phone calls to counsel families about pediatric emergency department (PED) use and primary care availability made after an index PED visit would modify subsequent PED use. Intervention: Follow-up phone call from the primary care practice within 72 hours of the initial PED visit to counsel about the availability of after-hours advice and when to access the PED. Main Outcome Measures: All subsequent visits to primary care practices, PED, pediatric subspecialists, or for inpatient hospitalization during a 365-day follow-up period. Logistic and ordinary least squares regressions estimated unadjusted and adjusted odds ratios of follow-up visits, controlling for covariates. Results: Of the 2166 intervention subjects, 816 (37.7%) recorded follow-up PED visits compared with 819 (39.4%) of the 2080 control subjects (P=.26, not significant). The adjusted odds of a follow-up visit being to the PED rather than to another venue was significantly less for intervention than for control subjects (odds ratio, 0.88; confidence interval, 0.82-0.94), indicating decreased intensity of PED use. Conclusion: Follow-up phone calls from primary care practices after PED visits counseling patients on the use of primary care and emergency services can modulate subsequent care-seeking behavior and decrease future PED use

Anisotropic strong lensing as a probe of dark matter self-interactions

Galaxy-scale strongly lensed systems have been shown to provide a unique technique for exploring the underlying physics of dark matter at sub-galactic scales. In the past, much attention was given to detecting and studying individual haloes in a strong lens system. In addition to the subhaloes, line-of-sight haloes contribute significantly to the small perturbations in lensed images. In prior work, we demonstrated that these line-of-sight haloes imprint a distinctive anisotropic signature and hence give rise to a detectable non-zero parity-even quadrupole moment in the effective convergence field's two-point correlation function. In this study, we show that these line-of-sight haloes also produce a non-zero curl component of the effective deflection field with a parity-odd quadrupole moment of the two-point function. These multipole moments have the ability to statistically separate line-of-sight haloes from dark matter substructure. In this paper, we examine how these multipole moments evolve in the presence of warm dark matter and self-interacting dark matter in terms of central density evolution and dark matter halo abundance. Importantly, we show that these different multipole moments display exquisite sensitivity to both the amplitude and the velocity dependence of the dark matter self-interaction cross-section. Our approach opens the door for strong lensing observations to probe dark matter self-interaction over a broad range of relative velocities.Comment: 12 pages, 9 figures + appendi

The Consequences and Costs of Maternal Substance Abuse in New York City

We use a pooled time-series cross-section of live births in New York City between 1980 and 1989 to investigate the dramatic rise in low birthweight, especially among Blacks, that occurred in the mid 1980s. After controlling for other risk factors, we estimate that the number of excess low birthweight births attributable to illicit substance abuse over this period ranged from approximately 1,900 to 3,800 resulting in excess neonatal admission costs of between $22 and$53 million. We conclude that illicit substance use was a major contributory factor in rapid rise of low birthweight among Blacks in New York City in the latter part of the 1980s. The impact of prenatal illicit substance use on Whites and Hispanics is less conclusive.