Peer Acceptance and Friendship as Predictors of Early Adolescents' Adjustment Across the Middle School Transition

This study examines several aspects of adolescents' pretransition peer relationships as predictors of their adjustment to middle school. Participants were 365 students (175 boys; 99% Caucasian) involved in the Time 1 (the spring of fifth grade) and Time 2 (the fall of sixth grade) assessments. Adolescents completed measures that assessed peer acceptance, number of friends, the quality of a specific mutual friendship, loneliness, depression, self-esteem, and involvement in school. Academic achievement and absentee data were obtained from student files. Regression analyses indicated that the pretransition peer variables predicted posttransition loneliness, self-esteem, school involvement, and academic achievement. The patterns of prediction varied slightly for each adjustment variable, with the most robust relationship being between peer acceptance and achievement. Results of repeated-measures MANOVAs indicated no differential changes in adjustment across time by gender. Implications for including a peer component in programs that prepare students for the middle school transition are discussed.

An assessment of self-concept and violence within a delinquent adolescent population

The purpose of this study was to provide further data on the relationship between self-concept and violence focusing on a delinquent adolescent population. Recent research has explored the relationship between self-concept and violence with most of the research being done with adult populations. Within the literature, there are two opposing views on the question of this relationship. The traditional view supports the idea that low self-esteem is a cause of violent behavior while the non-traditional view supports the idea that high self-esteem may be a contributor to violent behavior. ^ Using a sample of 200 delinquent adolescents 100 of whom had committed acts of violence and 100 who had not, a group comparison study was done which addressed the following questions, (1) within a delinquent population of violent and non-violent adolescents, is there a relationship between violence and self-concept? (2) what is that relationship; (3) using the Piers-Harris Children's Self-Concept Scale, can it be determined that attributes such as behavior, anxiety, popularity, happiness, and physical appearance as they relate to self-concept are more predictive than others in determining who within a delinquent population will commit acts of violence. For the purposes of this study, delinquent adolescents were those who had official records of misconduct with either the school or juvenile authorities. Adolescents classified as violent were those who had committed acts such as assault, use of a weapon, use of deadly force, and sexual assault while adolescents classified as non-violent had committed anti-social acts such as, truancy, talking back and rule breaking. ^ The study concluded that there is a relationship between adolescent violence and self-concept. However, there was insufficient statistical evidence that self-concept is a predictor of violence. ^

The Time-Series Properties on Housing Prices: A Case Study of the Southern California Market

We examine the time-series relationship between housing prices in eight Southern California metropolitan statistical areas (MSAs). First, we perform cointegration tests of the housing price indexes for the MSAs, finding seven cointegrating vectors. Thus, the evidence suggests that one common trend links the housing prices in these eight MSAs, a purchasing power parity finding for the housing prices in Southern California. Second, we perform temporal Granger causality tests revealing intertwined temporal relationships. The Santa Anna MSA leads the pack in temporally causing housing prices in six of the other seven MSAs, excluding only the San Luis Obispo MSA. The Oxnard MSA experienced the largest number of temporal effects from other MSAs, six of the seven, excluding only Los Angeles. The Santa Barbara MSA proved the most isolated in that it temporally caused housing prices in only two other MSAs (Los Angels and Oxnard) and housing prices in the Santa Anna MSA temporally caused prices in Santa Barbara. Third, we calculate out-of-sample forecasts in each MSA, using various vector autoregressive (VAR) and vector error-correction (VEC) models, as well as Bayesian, spatial, and causality versions of these models with various priors. Different specifications provide superior forecasts in the different MSAs. Finally, we consider the ability of theses time-series models to provide accurate out-of-sample predictions of turning points in housing prices that occurred in 2006:Q4. Recursive forecasts, where the sample is updated each quarter, provide reasonably good forecasts of turning points.

Efficient Unit Root Tests of real Exchange Rates in the Post-Bretton Woods Era

We apply the efficient unit-roots tests of Elliott, Rothenberg, and Stock (1996), and Elliott (1998) to twenty-one real exchange rates using monthly data of the G-7 countries from the post-Bretton Woods floating exchange rate period. Our results indicate that, for eighteen out of the twenty-one real exchange rates, the null hypothesis of a unit root can be rejected at the 10% significance level or better using the Elliot et al (1996) DF-GLS test. The unit-root null hypothesis is also rejected for one additional real exchange rate when we allow for one endogenously determined break in the time series of the real exchange rate as in Perron (1997). In all, we find favorable evidence to support long-run purchasing power parity in nineteen out of twenty-one real exchange rates. Second, we find no strong evidence to suggest that the use of non-U.S. dollar-based real exchange rates tend to produce more favorable result for long-run PPP than the use of U.S. dollar-based real exchange rates as Lothian (1998) has concluded.

Non-Parametric Tests of Real Exchange rates in the Post-Bretton Woods Era

This paper examines the mean-reverting property of real exchange rates. Earlier studies have generally not been able to reject the null hypothesis of a unit-root in real exchange rates, especially for the post-Bretton Woods floating period. The results imply that long-run purchasing power parity does not hold. More recent studies, especially those using panel unit-root tests, have found more favorable results, however. But, Karlsson and Löthgren (2000) and others have recently pointed out several potential pitfalls of panel unit-root tests. Thus, the panel unit-root test results are suggestive, but they are far from conclusive. Moreover, consistent individual country time series evidence that supports long-run purchasing power parity continues to be scarce. In this paper, we test for long memory using Lo's (1991) modified rescaled range test, and the rescaled variance test of Giraitis, Kokoszka, Leipus, and Teyssière (2003). Our testing procedure provides a non-parametric alternative to the parametric tests commonly used in this literature. Our data set consists of monthly observations from April 1973 to April 2001 of the G-7 countries in the OECD. Our two tests find conflicting results when we use U.S. dollar real exchange rates. However, when non-U.S. dollar real exchange rates are used, we find only two cases out of fifteen where the null hypothesis of an unit-root with short-term dependence can be rejected in favor of the alternative hypothesis of long-term dependence using the modified rescaled range test, and only one case when using the rescaled variance test. Our results therefore provide a contrast to the recent favorable panel unit-root test results.

Molecular markers of human papillomavirus (HPV) infection and epidemiologic risk factors for squamous intraepithelial lesions (SIL) of the cervix

Infection with certain types of HPV is a necessary event in the development of cervical carcinoma; however, not all women who become infected will progress. While much is known about the molecular influence of HPV E6 and E7 proteins on the malignant transformation, little is known about the additional factors needed to drive the process. Currently, conventional cervical screening is insufficient at identifying women who are likely to progress from premalignant lesions to carcinoma. Aneuploidy and chromatin texture from image cytometry have been suggested as quantitative measures of nuclear damage in premalignant lesions and cancer, and traditional epidemiologic studies have identified potential factors to aid in the discrimination of those lesions likely to progress. ^ In the current study, real-time PCR was used to quantitate mRNA expression of the E7 gene in women exhibiting normal epithelium, LSIL, and HSIL. Quantitative cytometry was used to gather information about the DNA index and chromatin features of cells from the same women. Logistic regression modeling was used to establish predictor variables for histologic grade based on the traditional epidemiologic risk factors and molecular markers. ^ Prevalence of mRNA transcripts was lower among women with normal histology (27%) than for women with LSIL (40%) and HSIL (37%) with mean levels ranging from 2.0 to 4.2. The transcriptional activity of HPV 18 was higher than that of HPV 16 and increased with increasing level of dysplasia, reinforcing the more aggressive nature of HPV 18. DNA index and mRNA level increased with increasing histological grade. Chromatin score was not correlated with histology but was higher for HPV 18 samples and those with both HPV 18 and HPV 16. However, chromatin score and DNA index were not correlated with mRNA levels. The most predictive variables in the regression modeling were mRNA level, DNA index, parity, and age, and the ROC curves for LSIL and HSIL indicated excellent discrimination. ^ Real-time PCR of viral transcripts could provide a more efficient method to analyze the oncogenic potential within cells from cervical swabs. Epidemiological modeling of malignant progression in the cervix should include molecular markers, as well as the traditional epidemiological risk factors. ^

A constellation of factors associated with premature births among African American women

A cohort, cross-sectional, historical study design was used to study factors related to spontaneous premature birth outcomes among African American women. The cohort consisted of 4,294 mothers drawn from the 1988 National Maternal and Infant Health Survey conducted by the National Center for Health Statistics. The objectives of the study were: (1) to examine the distribution of gestational ages of African American infants for selected variables reported for their families and (2) to describe risk factors associated with birth at 20–31 weeks of gestational age and at 32–36 weeks of gestational age. Risk factors examined include maternal age, maternal marital status, maternal living arrangements, maternal education, maternal work status, household income, gestational bleeding, month prenatal began, adequacy of prenatal care, parity, previous viable preterm birth, and behavioral factors of attitude toward pregnancy, smoking, drug, and alcohol use during pregnancy. Frequency distributions, cross tabulations, stratified analysis, and logistic regression analysis were used. ^ Risk factors associated with a 50 percent or more increase in preterm birth were cocaine use, low maternal education, teenaged mother, prenatal care deficits or overuse, and bleeding during the second half of pregnancy. The other risk factors of not living with the baby's father, smoking cigarettes and having a mistimed pregnancy carried statistically significance but lower strength of association. ^ Health care services, educational systems, and community organizations can develop and evaluate comprehensive health education and information campaigns that address preventable risk factors during pregnancy. Although preterm birth cannot always be prevented, preconception care can help identify and modify maternal risk and promote optimum health before conception. Quality care should include continued risk assessment, health promotion, and interventions. ^

African American female adolescents and antecedents of pregnancy

Although the pregnancy rate of teenage girls in the United States has decreased in recent years, African American female adolescents still have one of the highest teen pregnancy rates among girls in the United States. Previous studies report inconsistent relationships between adolescent pregnancy and self-esteem and parental communication, caring, and closeness. The purpose of this study was to assess relationships between pregnancy among African American female adolescents (7th to 12th grades) and self-esteem, communication levels and type of relationships with their parents. This study used data collected from The National Longitudinal Study of Adolescent Health (Add Health). Logistic regression analysis was used to determine if the independent variables of self-esteem, levels of parental caring and closeness and levels of communication with parents predicted the dependent variable of pregnancy. After controlling for age and levels of parental education, self-esteem was the only statistically significant variable that was associated with pregnancy. The findings of this study indicate that levels of self-esteem should be further investigated and that self-esteem may be an important factor when designing interventions to prevent adolescent pregnancy, particularly for African American females. ^

Physician coding for mental illness reimbursement and the need for mental health parity

Many patients with anxiety and depression initially seek treatment from their primary care physicians. Changes in insurance coverage and current mental parity laws, make reimbursement for services a problem. This has led to a coding dilemma for physicians seeking payment for their services. This study seeks to determine first the frequency at which primary care physicians use alternative coding, and secondly, if physicians would change their coding practices, provided reimbursement was assured through changes in mental parity laws. A mail survey was sent to 260 randomly selected primary care physicians, who are family practice, internal medicine, and general practice physicians, and members of the Harris County Medical Society. The survey evaluated the physicians' demographics, the number of patients with psychiatric disorders seen by primary care physicians, the frequency with which physicians used alternative coding, and if mental parity laws changed, the rate at which physicians would use a psychiatric illness diagnosis as the primary diagnostic code. The overall response rate was 23%. Only 47 of the 59 physicians, who responded, qualified for the study and of those 45% used a psychiatric disorder to diagnose patients with a primary psychiatric disorder, 47% used a somatic/symptom disorder, and 8% used a medical diagnosis. From the physicians who would not use a psychiatric diagnosis as a primary ICD-9 code, 88% were afraid of not being reimbursed and 12% were worried about stigma or jeopardizing insurability. If payment were assured using a psychiatric diagnostic code, 81% physicians would use a psychiatric diagnosis as the primary diagnostic code. However, 19% would use an alternative diagnostic code in fear of stigmatizing and/or jeopardizing patients' insurability. Although the sample size of the study design was adequate, our survey did not have an ideal response rate, and no significant correlation was observed. However, it is evident that reimbursement for mental illness continues to be a problem for primary care physicians. The reformation of mental parity laws is necessary to ensure that patients receive mental health services and that primary care physicians are reimbursed. Despite the possibility of improved mental parity legislation, some physicians are still hesitant to assign patients with a mental illness diagnosis, due to the associated stigma, which still plays a role in today's society. ^

Epidemiology of isolated obstructive genitourinary defect in Texas: 1999--2003

Background. Obstructive genitourinary defects include all anomalies causing obstruction anywhere along the urinary tract. Previous studies have noted a large excess of males among infants affected by these types of defects. This is the first epidemiologic study focused solely on obstructive genitourinary defects (OGD). ^ Methods. Data on 1,683 mild and 302 severe cases of isolated OGD born between 1999 and 2003 and ascertained by the Texas Birth Defects Registry were compared to all births in Texas during the same time period. Adjusted prevalence odds ratios (POR) were calculated for infant sex, birth weight, gestational age, mother’s race/ethnicity, mother’s age, mother’s education, parity, birth year, start of prenatal care, multiple birth, and public health region of birth. Severe cases were defined as those cases that died prior to birth, died after birth, or underwent surgery for OGD in the first year of life. Cases of OGD that had other major birth defects besides OGD were excluded from this study. ^ Results. Severe cases of OGD were more likely than mild cases to have multiple obstructive genitourinary anomalies (37.8% vs. 18.9%) and bilateral defects (40.9% vs. 31.3%). Males had a significantly greater risk of OGD than females for both severe and mild cases: adjusted POR = 3.26 (95% CI = 2.45-4.33) and adjusted POR = 2.60 (95% CI = 2.33-2.90), respectively. Infants with both severe and mild OGD were more likely to be very preterm birth at birth compared with infants without OGD: crude POR of 16.19 (95% CI = 10.60-24.74) and 4.75 (95% CI = 3.54-6.37), respectively. Among the severe group, minority races had a decreased risk of OGD with an adjusted POR of 0.74 (95% CI = 0.55-0.98) compared with whites. Among the mild cases, increased rates of OGD were found in older mothers (adjusted POR = 1.10, 95% CI = 1.05-1.15), college/higher educated mothers (adjusted POR = 1.07, 95% CI = 1.01-1.13) and multiple births (adjusted POR = 1.28, 95% CI = 1.01-1.62). There was also a decreased risk of mild cases among black mothers compared to whites (adjusted POR = 0.63, 95% CI = 0.52-0.76). Compared to 1999, the prevalence of mild cases of OGD increased significantly over the 5 year study period with an adjusted POR of 1.10 (95% CI = 1.06-1.15) by 2003. ^ Conclusion. Risk factors of OGD for both severe and mild forms were male sex and preterm birth. Severe cases were more likely to have multiple OGD defects and be affected bilaterally. An increase in prevalence of mild cases of OGD over time and differences in rates of black, older, and higher educated mothers in mild cases may be attributed to ultrasound use. ^

Improving the health and well-being of women at risk for neural tube defect recurrence

There is growing interest in providing women with internatal care, a package of healthcare and ancillary services that can improve their health during the period after the termination of one pregnancy but before the conception of the next pregnancy. Women who have had a pregnancy affected by a neural tube defect can especially benefit from internatal care because they are at increased risk for recurrence and improvements to their health during the inter-pregnancy period can prevent future negative birth outcomes. The dissertation provides three papers that inform the content of internatal care for women at risk for recurrence by examining descriptive epidemiology to develop an accurate risk profile of the population, assessing whether women at risk for recurrence would benefit from a psychosocial intervention, and determining how to improve health promotion efforts targeting folic acid use.^ Paper one identifies information relevant for developing risk profiles and conducting risk assessments. A number of investigations have found that the risk for neural tube defects differs between non-Hispanic Whites and Hispanics. To understand the risk difference, the descriptive epidemiology of spina bifida and anencephaly was examined for Hispanics and non-Hispanic Whites based on data from the Texas Birth Defects Registry for the years 1999 through 2004. Crude and adjusted birth prevalence ratios and corresponding 95% confidence intervals were calculated between descriptive epidemiologic characteristics and anencephaly and spina bifida for non-Hispanic Whites and for Hispanics. In both race/ethnic groups, anencephaly expressed an inverse relationship with maternal age and a positive linear relationship with parity. Both relationships were stronger in non-Hispanic Whites. Female infants had a higher risk for anencephaly in non-Hispanic Whites. Lower maternal education was associated with increased risk for spina bifida in Hispanics.^ Paper two assesses the need for a psychosocial intervention. For mothers who have children with spina bifida, the transition to motherhood can be stressful. This qualitative study explored the process of becoming a mother to a child with spina bifida focusing particularly on stress and coping in the immediate postnatal environment. Semi-structured interviews were conducted with six mothers who have children with spina bifida. Mothers were asked about their initial emotional and problem-based coping efforts, the quality and kind of support provided by health providers, and the characteristics of their meaning-based coping efforts; questions matched Transactional Model of Stress and Coping (TMSC) constructs. Analysis of the responses revealed a number of modifiable stress and coping transactions, the most salient being: health providers are in a position to address beliefs about self-causality and prevent mothers from experiencing the repercussions that stem from maintaining these beliefs. ^ Paper three identifies considerations when creating health promotion materials targeting folic acid use. A brochure was designed using concepts from the Precaution Adoption Process Model (PAPM). Three focus groups comprising 26 mothers of children with spina bifida evaluated the brochure. One focus group was conducted in Spanish-only, the other two focus groups were conducted in English and Spanish combined. Qualitative analysis of coded transcripts revealed that a brochure is a helpful adjunct. Questions about folic acid support the inclusion of an insert with basic information. There may be a need to develop different educational material for Hispanics so the importance of folic acid is provided in a situational context. Some participants blamed themselves for their pregnancy outcome which may affect their receptivity to messages in the brochure. The women's desire for photographs that affect their perception of threat and their identification with the second role model indicate they belong to PAPM Stage 2 and 3. Participants preferred colorful envelopes, high quality paper, intimidating photographs, simple words, conversational style sentences, and positive messages.^ These papers develop the content of risk assessment, psychosocial intervention, and health promotion components of internatal care as they apply to women at risk for recurrence. The findings provided evidence for considering parity and maternal age when assessing nutritional risk. The two dissimilarities between the two race/ethnic groups, infant sex and maternal education lent support to creating separate risk profiles. Interviews with mothers of children with spina bifida revealed the existence of unmet needs-suggesting that a psychosocial intervention provided as part of internatal care can strengthen and support women's well-being. Segmenting the audience according to race/ethnicity and PAPM stage can improve the relevance of print materials promoting folic acid use.^

The role of social support in HIV prevention among young Latino men who have sex with men

The purpose of this formative study was to determine and prioritize the HIV-prevention needs of Latino young men who have sex with men (YMSM) in Chihuahua (Mexico), Texas, and California, based on YMSM and service provider perceptions of the factors affecting the assimilation and implementation of HIV-preventive behaviors. These factors included: perceived social support, identification of the modes of HIV transmission, perceived risk of HIV, perceived norms and attitudes of peers.^ The study, drawn from a secondary data set, was a convenience sample of providers (n=8) and clients (n=15). Participants completed face-to face interviews and a survey instrument. Interviews were analyzed to identify common themes and congruence among client groups, and among clients and providers. Providers’ understanding of theoretical constructs of interventions was also assessed. Survey data were analyzed to determine variable frequencies and their congruence to the qualitative analysis. ^ The results revealed several differences and many commonalities in the assimilation of protective messages. Client and provider perceptions were congruent across all domains. Providers demonstrated intuitive command of theoretical concepts but inconsistently verbalized their application. Both clients and providers recognized Latinos possessed high HIV-knowledge levels, despite inconsistent protective behaviors. Clients and providers consistently identified important reasons leading to inconsistent protective behaviors, such as: lack of access to targeted information and condoms, self-esteem, sexual identification, situational factors, decreased perceived HIV-risk, and concerns about homophobia, stigma, and rejection. Other factors included: poverty, failure to reach disenfranchised populations, and lack of role models/positive parental figures. The principal conclusion of the study was that there is a need for further study to understand the interrelationship between larger socioeconomic issues and consistent protective behaviors.^

The cost of publicly financed dental care in relation to community water fluoridation in Texas

Dental caries lead to children being less ready to learn and results in diminished productivity in the classroom. Tooth decay causes pain and infection, leading to impaired chewing, speech, and facial expression, in addition to a loss in self-esteem. There have been many studies supporting the safety and efficacy of community water fluoridation in reducing dental caries. Water fluoridation has been identified by the Centers for Disease Control and Prevention as one of 10 great public health achievements of the 20th century. The decline in the prevalence and severity of tooth decay in the United States during the past 60 years has been attributed largely to the increased use of fluoride; in particular, the widespread utilization of community water fluoridation. However, in the decades since fluoridation was first introduced, reductions in dental caries have declined, most likely due to the presence of other sources of fluoride. Questions have been raised regarding the need to continue to fluoridate community water supplies in the face of possible excessive exposure to fluoride. Nevertheless, dental caries continue to be a significant public health burden throughout the world, including the United States, especially among low-income and disadvantaged populations. Although many poor children receive their dental care through Medicaid, the percentage of Texas children with untreated dental caries continues to exceed the U.S. average and is well above Healthy People 2010 goals, even as state Medicaid expenditures continue to rise. The objective of this study is to determine the relationship between Medicaid dental expenditures and community water fluoridation levels in Texas counties. By examining this relationship, the cost-effectiveness of community water fluoridation in the Texas pediatric Medicaid beneficiary population, as measured by publicly financed dental care expenditures, may be ascertained.^

The relationship between calcium and fluoride intake, pregnancy and lactation and the risk of height loss in white women

This study was designed to investigate the effect of calcium and fluoride intake, and parity and lactation on the risk of spinal osteoporosis. Height loss was used as a surrogate measure for spinal fractures by taking advantage of documented changes in height found during the 25-year follow-up of the Charleston Heart Study cohort. Women who had lost 2-4" in height or who had no change in height during the follow-up period were defined as case and comparison subjects respectively. Calcium intake when the subjects were "about 25" and in the recent past, average intake of fluoride over 25 years, and parity and history of breastfeeding were ascertained by questionnaire from 54 case and 77 comparison subjects. Low calcium intake in the past decreased the risk of height loss (age-adjusted OR = 0.3, 95%CI: 0.1-0.96) although several potentially important confounding variables could not be adjusted for. There was no association between risk of height loss and present calcium intake (OR = 0.8, 95%CI: 0.3-2.6 for low versus high intake) after adjustment for past calcium intake. High fluoride intake decreased the risk of height loss (adjusted OR = 0.4, 95%CI: 0.1-1.2). The effect of fluoride or calcium intake in the present was modified by the level of the other nutrient. Compared to a low intake of both calcium and fluoride, a high intake of one increased the risk of height loss (crude OR = 3.3 for high fluoride/low calcium, crude OR = 6.0 for high calcium/low fluoride) although a high intake of both was slightly protective (crude OR = 0.7). It is estimated that a "high" nutrient intake in this population was greater than 850mg/day for calcium and 2mg/day for fluoride. After adjustment for age, increasing parity decreased the risk of height loss in women who had never breastfed (OR = 0.2, 95%CI: 0.01-1.7 for 4 or more children). Women who had breastfed were also at lower risk of height loss than nulliparous women (OR = 0.3, 95%CI: 0.1-1.2 for 4 or more children) although at any level of parity, breastfeeding women had a greater risk of height loss than did non-breastfeeding women. ^

The use of the computerized and revised vital record in conducting etiologic studies on neural tube defects

The purpose of this study was to evaluate the adequacy of computerized vital records in Texas for conducting etiologic studies on neural tube defects (NTDs), using the revised and expanded National Centers for Health Statistics vital record forms introduced in Texas in 1989.^ Cases of NTDs (anencephaly and spina bifida) among Harris County (Houston) residents were identified from the computerized birth and death records for 1989-1991. The validity of the system was then measured against cases ascertained independently through medical records and death certificates. The computerized system performed poorly in its identification of NTDs, particularly for anencephaly, where the false positive rate was 80% with little or no improvement over the 3-year period. For both NTDs the sensitivity and predictive value positive of the tapes were somewhat higher for Hispanic than non-Hispanic mothers.^ Case control studies were conducted utilizing the tape set and the independently verified data set, using controls selected from the live birth tapes. Findings varied widely between the data sets. For example, the anencephaly odds ratio for Hispanic mothers (vs. non-Hispanic) was 1.91 (CI = 1.38-2.65) for the tape file, but 3.18 (CI = 1.81-5.58) for verified records. The odds ratio for diabetes was elevated for the tape set (OR = 3.33, CI = 1.67-6.66) but not for verified cases (OR = 1.09, CI = 0.24-4.96), among whom few mothers were diabetic. It was concluded that computerized tapes should not be solely relied on for NTD studies.^ Using the verified cases, Hispanic mother was associated with spina bifida, and Hispanic mother, teen mother, and previous pregnancy terminations were associated with anencephaly. Mother's birthplace, education, parity, and diabetes were not significant for either NTD.^ Stratified analyses revealed several notable examples of statistical interaction. For anencephaly, strong interaction was observed between Hispanic origin and trimester of first prenatal care.^ The prevalence was 3.8 per 10,000 live births for anencephaly and 2.0 for spina bifida (5.8 per 10,000 births for the combined categories). ^