The prevalence of food insecurity and associated factors among households with children in Head Start programs in Houston, Texas and Birmingham, Alabama

The purposes of this study were to determine the prevalence of food insecurity and factors associated with food insecurity among households with children enrolled in Head Start programs in Houston, Texas, and Birmingham, Alabama. This cross-sectional study utilized data gathered from 688 households recruited by convenience sample from two Head Start districts in each city. Interviewers collected data from primary caregivers on demographic characteristics, dietary intake, and the six-item USDA food security module. Chi-square and logistic regression analysis were used to determine the association of food security and demographic characteristics. Comparison of means was used to analyze the association between the child's fruit and vegetable intake and the household's food security status. The prevalence of food insecurity among the sample was 34.9% (95% CI: 31.3%, 38.5%). Characteristics associated with food insecurity were the caregiver's national origin (Foreign-born (ref.) v. U.S.-born, adjusted OR = 0.36, 95% CI: 0.14, 0.94), gender of the child (male (ref.) v. female, adjusted OR = 1.44, 95% CI: 1.03, 2.01), and city of residence (Birmingham (ref.) v. Houston, adjusted OR = 0.20, 95% CI: 0.10, 0.39). Children in food insecure households consumed more daily servings of fruits and vegetables on average (mean = 2.44) than children in food secure households (mean = 2.16, p = 0.04). ^

Factor H variant Y402H and the prevalence of hypertension and proteinuria: The Atherosclerosis Risk in Communities study

Hypertension is a significant risk factor for cardiovascular disease, which in turn is a major cause of morbidity and mortality worldwide. While the pathogenesis of vascular injury and subsequent end organ damage is complex, there is emerging data to support a role for the complement system in endovascular diseases. The complement Factor H Y402H polymorphism has been associated with a number of vasculopathies, including age-related macular degeneration (AMD), ischemic stroke and myocardial infarction. The current study evaluated the relationship of the Y402H polymorphism with hypertension and microalbuminuria in large the bi-racial Atherosclerosis Risk in Communities (ARIC) study. The Y402H polymorphism was found to be associated with a 48% (p-value 0.042) increase in the risk of developing incident hypertension in African American participants. No significant association was found with the Y402H polymorphism and microalbuminuria. The results from this investigation reveal the first association of the Factor H Y402H polymorphism and an increased risk of incident hypertension in African Americans. ^

The prevalence, health risks, and consequences of asthma among adult residents in Texas

Based on asthma prevalence data collected from the 2000 BRFSS survey, approximately 14.7 million U.S. adults had current asthma, accounting for 7.2% of the total U.S. population. In Texas alone, state data extrapolated from the 1999-2003 Texas BRFSS suggested that approximately 1 million Texas adults were reporting current asthma and approximately 11% of the adult population has been diagnosed with the illness during their lifetime. From a public health perspective, the disease is manageable. Comprehensive state-specific asthma surveillance data are necessary to identify disparities in asthma prevalence and asthma-control characteristics among subpopulations and to develop targeted public health interventions. The purpose of this study was to determine the relative importance of various risk factors of asthma and to examine the impact of asthma on health-related quality of life among adult residents of Texas. ^ The study employed a cross-sectional study of respondents in Texas. The study extracted all the variables related to asthma along with their associated demographic, socioeconomic, and quality of life variables from the 2007 BRFSS data for 17,248 adult residents of Texas aged 18 and older. Chi-square test and logistic regression using SPSS were used in various data analyses on weighted data, adjusting for the complex sample design of the BRFSS data. All chi-square analyses were carried out using SPSS's CSTABULATE command. In addition, logistic regression models were fitted using SPSS's CSLOGISTIC command. ^ Risks factors significantly associated with reporting current asthma included BMI, race/ethnicity, gender, and income. Holding all other variables constant, obese adults were almost twice as likely to report current asthma as those adults who were normal weight (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.25 to 2.53). Other non-Hispanic adults were significantly more likely to report current asthma than non-Hispanic Whites (OR, 2.43; 95% CI, 1.38 to 4.25), while Hispanics were significantly less likely to report current asthma than non-Hispanic Whites (OR, 0.38; 95% CI, 0.25 to 0.60), after controlling for all other variables. After adjusting for all other variables, adult females were almost twice as likely to report current asthma as males (OR, 1.97; 95% CI, 1.49 to 2.60). Adults with household income of less than $15,000 were almost twice as likely to report current asthma as those persons with an annual household income of $50,000 or more (OR, 1.98; 95% CI, 1.33 to 2.94). In regards to the association between asthma and health-related quality of life, after adjusting for age, race/ethnicity, gender, tobacco use, body mass index (BMI), exercise, education, and income, adults with current asthma compared to those without asthma were more likely to report having more than 15 days of unhealthy physical health (OR, 1.84; 95% CI, 1.29 to 2.60). ^ Overall, the findings of this study provide insight and valuable information into the populations in Texas most adversely affected by asthma and health-related consequences of the disease condition. Further research could build on the findings of this study by replicating this study as closely as possible in other asthma settings, and look at the relationship for hospitalization rates, asthma severity, and mortality.^

Hepatitis B and C infections in U.S. incarcerated populations: Prevalence and related mortality

Published reports have consistently indicated high prevalence of serologic markers for hepatitis B (HBV) and hepatitis C (HCV) infection in U.S. incarcerated populations. Quantifying the current and projected burden of HBV and HCV infection and hepatitis-related sequelae in correctional healthcare systems with even modest precision remains elusive, however, because the prevalence and sequelae of HBV and HCV in U.S. incarcerated populations are not well-studied. This dissertation contributes to the assessment of the burden of HBV and HCV infections in U.S. incarcerated populations by addressing some of the deficiencies and gaps in previous research. ^ Objectives of the three dissertation studies were: (1) To investigate selected study-level factors as potential sources of heterogeneity in published HBV seroprevalence estimates in U.S. adult incarcerated populations (1975-2005), using meta-regression techniques; (2) To quantify the potential influence of suboptimal sensitivity of screening tests for antibodies to hepatitis C virus (anti-HCV) on previously reported anti-HCV prevalence estimates in U.S. incarcerated populations (1990-2005), by comparing these estimates to error-adjusted anti-HCV prevalence estimates in these populations; (3) To estimate death rates due to HBV, HCV, chronic liver disease (CLD/cirrhosis), and liver cancer from 1984 through 2003 in male prisoners in custody of the Texas Department of Criminal Justice (TDCJ) and to quantify the proportion of CLD/cirrhosis and liver cancer prisoner deaths attributable to HBV and/or HCV. ^ Results were as follows. Although meta-regression analyses were limited by the small body of literature, mean population age and serum collection year appeared to be sources of heterogeneity, respectively, in prevalence estimates of antibodies to HBV antigen (HBsAg+) and any positive HBV marker. Other population characteristics and study methods could not be ruled out as sources of heterogeneity. Anti-HCV prevalence is likely somewhat higher in male and female U.S. incarcerated populations than previously estimated in studies using anti-HCV screening tests alone without the benefit of repeat or additional testing. Death rates due to HBV, HCV, CLD/cirrhosis, and liver cancer from 1984 through 2003 in TDCJ male prisoners exceeded state and national rates. HCV rates appeared to be increasing and disproportionately affecting Hispanics. HCV was implicated in nearly one-third of liver cancer deaths. ^

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. ^

Birth prevalence of isolated congenital limb reduction defects in Texas 1999--2001

Objective. Congenital limb defects are common birth defects occurring in approximately 2-7/10,000 live births. Because congenital limb defects are pervasive throughout all populations, and the conditions profoundly affect quality of life, they represent a significant public health concern. Currently there is a paucity of etiologic information in the literature regarding congenital limb reduction defects which represents a major limitation in developing treatment strategies as well as identifying high risk pregnancies. ^ Additionally, despite the fact that the majority of congenital limb reduction defects are isolated, most previous studies have not separated them from those occurring as part of a known syndrome or with multiple additional congenital anomalies of unknown etiology. It stands to reason that factors responsible for multiple congenital anomalies that happen to include congenital limb reduction defects may be quite different from those factors leading to an isolated congenital limb reduction defect. ^ As a first step toward gaining etiologic understanding, this cross-sectional study was undertaken to determine the birth prevalence and obtain demographic information about non-syndromic (isolated) congenital limb reduction defects that occurred in Texas from 1999-2001. ^ Methods. The study population included all infants/fetuses with isolated congenital limb reduction defects born in Texas during 1999-2001; the comparison population was all infants who were born to mothers who were residents of Texas during the same period of time. The overall birth prevalence of limb reduction defects was determined and adjusted for ethnicity, gender, site of defect (upper limb versus lower limb), county of residence, maternal age and maternal education. ^ Results. In Texas, the overall birth prevalence of isolated CLRDs was 2.1/10,000 live births (1.5 and 0.6/10,000 live births for upper limb and lower limb, respectively). ^ The risk of isolated lower limb CLRDs in Texas was significantly lower in females when gender was examined individually (crude prevalence odds ratio of 0.57, 95% CI of 0.36-0.91) as well as in relation to all other variables used in the analysis (adjusted prevalence odds ratio of 0.58, 95% CI of 0.36-0.93). ^ Harris County (which includes the Houston metropolitan area) had significantly lower risks of all (upper limb and lower limb combined) isolated CLRDs when examined in relation to other counties in Texas, with a crude prevalence odds ratio of 0.4 (95% CI: 0.29-0.72) and an adjusted prevalence odds ratio of 0.50 (95% CI: 0.31-0.80). The risk of isolated upper limb CLRDs was significantly lower in Harris County (crude prevalence odds ratio of 0.45, CI of 0.26-0.76 and adjusted prevalence odds ratio of 0.49, CI of 0.28-0.84). This trend toward decreased risk in Harris County was not observed for isolated lower limb reduction defects (adjusted prevalence odds ratio of 0.50, 95% confidence interval: 0.22-1.12). ^ Conclusions. The birth prevalence of isolated congenital limb reduction defects in Texas is in the lower limits of the range of rates that have been reported by other authors for other states (Alabama, Arkansas, California, Georgia, Hawaii, Iowa, Maryland, Massachusetts, North Carolina, Oklahoma, Utah, Washington) and other countries (Argentina, Australia, Austria, Bolivia, Brazil, Canada, Chile, China, Colombia, Costa Rica, Croatia, Denmark, Ecuador, England, Finland, France, Germany, Hungary, Ireland, Israel, Italy, Lithuania, Mexico, Norway, Paraguay, Peru, Spain, Scotland, Sweden, Switzerland, Uruguay, and Venezuela). In Texas, the birth prevalence of isolated congenital lower limb reduction defects was greater for males than females, while the birth prevalence of isolated congenital upper limb reduction defects was not significantly different between males and females. The reduced rates of limb reduction defects in Harris County warrant further investigation. This study has provided an important first step toward gaining etiologic understanding in the study of isolated congenital limb reduction defects. ^

Disparities in asthma prevalence: The influence of sociodemographic and workplace factors

Asthma is a serious and continuing health problem that affects millions of Americans. Our study was conducted in response to this serious health problem and for purposes of addressing the issue of potential health disparities as outlined in Healthy People 2010. Data from sub-populations of subjects who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999-2004 were used to complete the following specific aims: (1) to update nationally-based estimates of the prevalence of current and lifetime (ever) asthma among adults in the United States (U.S.) and describe by gender the relationships between potential risk factors (e.g., sociodemographics and lifestyle) and asthma; (2) to describe demographic characteristics among working adults in the U.S. and update estimates of the prevalence of asthma in this sub-population, stratified by occupation and industry; and 3) to determine the utility of adapting a population-based Job Exposure Matrix (JEM) for classifying workplace exposures to asthmagens. ^ Our findings suggest the prevalence of asthma among U.S. adults is continuing to rise, with women having a higher prevalence of asthma than men. Living below the poverty threshold, obesity, and prior history of smoking remain important determinants of asthma. Our study also adds to the increasing evidence that health care workers (HCWs) and those employed in education remain at high risk and that appropriate evaluation and control measures need to be implemented. Over 78% of HCWs and 71% of teachers in our study were females suggesting that further exploration of gender-specific risk factors of asthma in working populations is needed. ^ Our study also addressed the feasibility of adapting a population-based asthma-specific JEM to NHANES (1999-2004). We were not able to apply the asthma-specific JEM due to the broad occupational categories within NHANES. This represents a missed opportunity to examine the association between workplace exposures and asthma in U.S. working adults. However, we have identified steps that may be implemented in future population-based studies that would allow the asthma-specific JEM (and other population-based job exposure matrices) to be used in future studies of the U.S. working population.^

Automated soldier medical readiness: Prevalence of " medically not ready" using data from the electronic soldier readiness processing system (ESRP)

Identifying accurate numbers of soldiers determined to be medically not ready after completing soldier readiness processing may help inform Army leadership about ongoing pressures on the military involved in long conflict with regular deployment. In Army soldiers screened using the SRP checklist for deployment, what is the prevalence of soldiers determined to be medically not ready? Study group. 15,289 soldiers screened at all 25 Army deployment platform sites with the eSRP checklist over a 4-month period (June 20, 2009 to October 20, 2009). The data included for analysis included age, rank, component, gender and final deployment medical readiness status from MEDPROS database. Methods.^ This information was compiled and univariate analysis using chi-square was conducted for each of the key variables by medical readiness status. Results. Descriptive epidemiology Of the total sample 1548 (9.7%) were female and 14319 (90.2%) were male. Enlisted soldiers made up 13,543 (88.6%) of the sample and officers 1,746 (11.4%). In the sample, 1533 (10.0%) were soldiers over the age of 40 and 13756 (90.0%) were age 18-40. Reserve, National Guard and Active Duty made up 1,931 (12.6%), 2,942 (19.2%) and 10,416 (68.1%) respectively. Univariate analysis. Overall 1226 (8.0%) of the soldiers screened were determined to be medically not ready for deployment. Biggest predictive factor was female gender OR (2.8; 2.57-3.28) p<0.001. Followed by enlisted rank OR (2.01; 1.60-2.53) p<0.001. Reserve component OR (1.33; 1.16-1.53) p<0.001 and Guard OR (0.37; 0.30-0.46) p<0.001. For age > 40 demonstrated OR (1.2; 1.09-1.50) p<0.003. Overall the results underscore there may be key demographic groups relating to medical readiness that can be targeted with programs and funding to improve overall military medical readiness.^

Genetic epidemiology of gallbladder disease in Mexican Americans and cholesterol 7$\alpha$-hydroxylase gene sequence variation

Among Mexican Americans, the second largest minority group in the United States, the prevalence of gallbladder disease is markedly elevated. Previous data from both genetic admixture and family studies indicate that there is a genetic component to the occurrence of gallbladder disease in Mexican Americans. However, prior to this thesis no formal genetic analysis of gallbladder disease had been carried out nor had any contributing genes been identified.^ The results of complex segregation analysis in a sample of 232 Mexican American pedigrees documented the existence of a major gene having two alleles with age- and gender-specific effects influencing the occurrence of gallbladder disease. The estimated frequency of the allele increasing susceptibility was 0.39. The lifetime probabilities that an individual will be affected by gallbladder disease were 1.0, 0.54, and 0.00 for females of genotypes "AA", "Aa", and "aa", respectively, and 0.68, 0.30, and 0.00 for males, respectively. This analysis provided the first conclusive evidence for the existence of a common single gene having a large effect on the occurrence of gallbladder disease.^ Human cholesterol 7$\alpha$-hydroxylase is the rate-limiting enzyme in bile acid synthesis. The results of an association study in both a random sample and a matched case/control sample showed that there is a significant association between cholesterol 7$\alpha$-hydroxylase gene variation and the occurrence of gallbladder disease in Mexican Americans males but not in females. These data have implicated a specific gene, 7$\alpha$-hydroxylase, in the etiology of gallbladder disease in this population.^ Finally, I asked whether the inferred major gene from complex segregation analysis is genetically linked to the cholesterol 7$\alpha$-hydroxylase gene. Three pedigrees predicted to be informative for linkage analysis by virtue of supporting the major gene hypothesis and having parents with informative genotypes and multiple offspring were selected for this linkage analysis. In each of these pedigrees, the recombination fractions maximized at 0 with a positive, albeit low, LOD score. The results of this linkage analysis provide preliminary and suggestive evidence that the cholesterol 7$\alpha$-hydroxylase gene and the inferred gallbladder disease susceptibility gene are genetically linked. ^

A STUDY ON THE EPIDEMIOLOGY OF POSITIVE PHYSICAL HEALTH (NHANES I)

HANES 1 detailed sample data were used to operationalize a definition of health in the absence of disease and to describe and compare the characteristics of the normal (healthy) group versus an abnormal (unhealthy) group.^ Parallel screening gave a 3.8 percent prevalence proportion of physical health, with a female:male ratio of 2:1 and younger ages in the healthy group. Statistically significant Mantel-Haenszel gender-age-adjusted odds ratios (MHOR) were estimated among abnormal non-migrants (1.53), skilled workers/unemployed (1.76), annual family incomes of less than $10,000 (1.56), having ever smoked (1.58), and started smoking before 18 years of age (1.58). Significant MHOR were also found for abnormals for health promoting measures: non-iodized salt use (1.94), needed dental care (1.91); and for fair to poor perceived health (4.28), perceiving health problems (2.52), and low energy level (1.68). Significant protective effects for much to moderate recreational exercise (MHOR 0.42) and very active to moderate non-recreational activity (MHOR 0.49) were also obtained. Covariance analysis additive models detected statistically significant higher mean values for abnormals than normals for serum magnesium, hemoglobin, hematocrit, urinary creatinine, and systolic and diastolic blood pressures, and lower values for abnormals than normals for serum iron. No difference was detected for serum cholesterol. Significant non-additive joint effects were found for body mass index.^ The results suggest positive physical health can be measured with cross-sectional survey data. Gender differentials, and associations between ecologic, socioeconomic, hazardous risk factors, health promoting activities and physical health are in general agreement with published findings on studies of morbidity. Longitudinal prospective studies are suggested to establish the direction of the associations and to enhance present knowledge of health and its promoting factors. ^

Venous thromboembolism in patients with acute leukemia: Prevalence, incidence, recurrence of thrombosis, risk factors, and impact on survival

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is the third most preventable cardiovascular disease and a growing public health problem in the United States. The incidence of VTE remains high with an annual estimate of more than 600,000 symptomatic events. DVT affects an estimated 2 million American each year with a death toll of 300,000 persons per year from DVT-related PE. Leukemia patients are at high risk for both hemorrhage and thrombosis; however, little is known about thrombosis among acute leukemia patients. The ultimate goal of this dissertation was to obtain deep understanding of thrombotic issue among acute leukemia patients. The dissertation was presented in a format of three papers. First paper mainly looked at distribution and risk factors associated with development of VTE among patients with acute leukemia prior to leukemia treatment. Second paper looked at incidence, risk factors, and impact of VTE on survival of patients with acute lymphoblastic leukemia during treatment. Third paper looked at recurrence and risk factors for VTE recurrence among acute leukemia patients with an initial episode of VTE. Descriptive statistics, Chi-squared or Fisher's exact test, median test, Mann-Whitney test, logistic regression analysis, Nonparametric Estimation Kaplan-Meier with a log-rank test or Cox model were used when appropriate. Results from analyses indicated that acute leukemia patients had a high prevalence, incidence, and recurrent rate of VTE. Prior history of VTE, obesity, older age, low platelet account, presence of Philadelphia positive ALL, use of oral contraceptives or hormone replacement therapy, presence of malignancies, and co-morbidities may place leukemia patients at an increased risk for VTE development or recurrence. Interestingly, development of VTE was not associated with a higher risk of death among hospitalized acute leukemia patients.^

Lifetime prevalence and risk factors for cancer in a Mexican American population with severe health disparities: The Cameron County Hispanic Cohort

Retrospective data from the Cameron Country Hispanic Cohort (1) were analyzed to assess the burden of cancer in the Mexican American population living in Brownsville TX. Data provided by the study participants for themselves and their parents and other extended relatives on cancer and related risk factors were used to determine both the prevalence of cancer and these risk factors as well as any associations between them. Lifetime incidence of cancer among the study participants was of 2.8%. Lifetime incidence of cancer among the parents of the study population was calculated for cancer in general and for specific cancer sites to determine the ranking of occurrence of each type of cancer. Some cancer types in this population were ranked higher than what would be expected when compared with national data from Hispanics in the U.S, these were: Liver cancer (3rd vs. 7th nationally in males and 6th vs. 13th nationally in females), stomach cancer (4th vs. 8th nationally in males and 5th vs. 11th nationally in females) and ovarian cancer (3rd vs. 8th nationally in females). A significant association with cancer was found for being born in the United States compared to being born elsewhere (O.R. 1.62, 95% C.I. 1.01–2.60) among study participants and the same association was also found between birth of parents in the United States regardless of gender for cancers in general (O.R. 1.38 95% C.I. 1.12–1.70), stomach cancer (O.R. 1.92 95% C.I. 1.01–3.67) and colorectal cancer (O.R. 2.93 95% C.I. 1.28–6.72). Having been born in the United States and having a family history of cancer was also found to be significantly associated with other risk factors for cancer such as obesity, diabetes and insulin resistance, both among the parents and the participant population, suggesting these interactions are complex. These high rates of cancer and particular prominence of less usual cancer such as liver and ovary in health disparities warrant evaluation of early detection strategies.^

HIV prevalence and contextual risk-factors among injection drug users in Harris County, Texas

Injection drug use is the third most frequent risk factor for new HIV infections in the United States. A dual mode of exposure: unsafe drug using practices and risky sexual behaviors underlies injection drug users' (IDUs) risk for HIV infection. This research study aims to characterize patterns of drug use and sexual behaviors and to examine the social contexts associated with risk behaviors among a sample of injection drug users. ^ This cross-sectional study includes 523 eligible injection drug users from Houston, Texas, recruited into the 2009 National HIV Behavioral Surveillance project. Three separate set of analyses were carried out. First, using latent class analysis (LCA) and maximum likelihood we identified classes of behavior describing levels of HIV risk, from nine drug and sexual behaviors. Second, eight separate multivariable regression models were built to examine the odds of reporting a given risk behavior. We constructed the most parsimonious multivariable model using a manual backward stepwise process. Third, we examined whether HIV serostatus knowledge (self-reported positive, negative, or unknown serostatus) is associated with drug use and sexual HIV risk behaviors. ^ Participants were mostly male, older, and non-Hispanic Black. Forty-two percent of our sample had behaviors putting them at high risk, 25% at moderate risk, and 33% at low risk for HIV infection. Individuals in the High-risk group had the highest probability of risky behaviors, categorized as almost always sharing needles (0.93), seldom using condoms (0.10), reporting recent exchange sex partners (0.90), and practicing anal sex (0.34). We observed that unsafe injecting practices were associated with high risk sexual behaviors. IDUs who shared needles had higher odds of having anal sex (OR=2.89, 95%CI: 1.69-4.92) and unprotected sex (OR=2.66, 95%CI: 1.38-5.10) at last sex. Additionally, homelessness was associated with needle sharing (OR=2.24, 95% CI: 1.34-3.76) and cocaine use was associated with multiple sex partners (OR=1.82, 95% CI: 1.07-3.11). Furthermore, twenty-one percent of the sample was unaware of their HIV serostatus. The three groups were not different from each other in terms of drug-use behaviors: always using a new sterile needle, or in sharing needles or drug preparation equipment. However, IDUs unaware of their HIV serostatus were 33% more likely to report having more than three sexual partners in the past 12 months; 45% more likely to report to have unprotected sex and 85% more likely to use drug and or alcohol during or before at last sex compared to HIV-positive IDUs. ^ This analysis underscores the merit of LCA approach to empirically categorize injection drug users into distinct classes and identify their risk pattern using multiple indicators and our results show considerable overlap of high risk sexual and drug use behaviors among the high-risk class members. The observed clustering pattern of drug and sexual risk behavior among this population confirms that injection drug users do not represent a homogeneous population in terms of HIV risk. These findings will help develop tailored prevention programs.^

The epidemiology of left ventricular outflow tract obstruction defects in Texas, 2002-2008: An update and assessment of effect heterogeneity

Left ventricular outflow tract (LVOT) defects are an important group of congenital heart defects (CHDs) because of their associated mortality and long-term complications. LVOT defects include aortic valve stenosis (AVS), coarctation of aorta (CoA), and hypoplastic left heart syndrome (HLHS). Despite their clinical significance, their etiology is not completely understood. Even though the individual component phenotypes (AVS, CoA, and HLHS) may have different etiologies, they are often "lumped" together in epidemiological studies. Though "lumping" of component phenotypes may improve the power to detect associations, it may also lead to ambiguous findings if these defects are etiologically distinct. This is due to potential for effect heterogeneity across component phenotypes. ^ This study had two aims: (1) to identify the association between various risk factors and both the component (i.e., split) and composite (i.e., lumped) LVOT phenotypes, and (2) to assess the effect heterogeneity of risk factors across component phenotypes of LVOT defects. ^ This study was a secondary data analysis. Primary data were obtained from the Texas Birth Defect Registry (TBDR). TBDR uses an active surveillance method to ascertain birth defects in Texas. All cases of non complex LVOT defects which met our inclusion criteria during the period of 2002–2008 were included in the study. The comparison groups included all unaffected live births for the same period (2002–2008). Data from vital statistics were used to evaluate associations. Statistical associations between selected risk factors and LVOT defects was determined by calculating crude and adjusted prevalence ratio using Poisson regression analysis. Effect heterogeneity was evaluated using polytomous logistic regression. ^ There were a total of 2,353 cases of LVOT defects among 2,730,035 live births during the study period. There were a total of 1,311 definite cases of non-complex LVOT defects for analysis after excluding "complex" cardiac cases and cases associated with syndromes (n=168). Among infant characteristics, males were at a significantly higher risk of developing LVOT defects compared to females. Among maternal characteristics, significant associations were seen with maternal age > 40 years (compared to maternal age 20–24 years) and maternal residence in Texas-Mexico border (compared to non-border residence). Among birth characteristics, significant associations were seen with preterm birth and small for gestation age LVOT defects. ^ When evaluating effect heterogeneity, the following variables had significantly different effects among the component LVOT defect phenotypes: infant sex, plurality, maternal age, maternal race/ethnicity, and Texas-Mexico border residence. ^ This study found significant associations between various demographic factors and LVOT defects. While many findings from this study were consistent with results from previous studies, we also identified new factors associated with LVOT defects. Additionally, this study was the first to assess effect heterogeneity across LVOT defect component phenotypes. These findings contribute to a growing body of literature on characteristics associated with LVOT defects. ^

Literature review of estimation of prevalence rate of HIV/AIDS in India using population survey and sentinel surveillance based data

HIV/AIDS is a treatable although incurable disease that presents immense challenges to those infected including physical, social and psychological effects. As of 2009, an estimated 2.4 million people were living with HIV or AIDS in India, 0.3% of the country's population. In India, it is difficult to not only treat but also to track because it is associated with socio-economic factors such as illiteracy, social biases, poor sanitation, malnutrition and social class. Nevertheless, it is important to know the prevalence of HIV/AIDS for several reasons. At the individual level, the quality of life of people living with HIV/AIDS is markedly lower than their counterparts without the disease and is associated with challenges. At the community level, it is important to identify high risk groups, monitor prevention efforts, and allocate appropriate resources to target programs for the reduction of transmission of HIV. ^