Community Trails in Community Context: GIS Analysis of Associations between Trail and Neighborhood Characteristics

This research examines the site and situation characteristics of community trails as landscapes promoting physical activity. Trail segment and neighborhood characteristics for six trails in urban, suburban, and exurban towns in northeastern Massachusetts were assessed from primary Global Positioning System (GPS) data and from secondary Census and land use data integrated in a geographic information system (GIS). Correlations between neighborhood street and housing density, land use mix, and sociodemographic characteristics and trail segment characteristics and amenities measure the degree to which trail segment attributes are associated with the surrounding neighborhood characteristics.

Are Shirking and Leisure Substitutable? An Empirical Test of Efficiency Wages Based on Urban Economic Theory

Recent theoretical work has examined the spatial distribution of unemployment using the efficiency wage model as the mechanism by which unemployment arises in the urban economy. This paper extends the standard efficiency wage model in order to allow for behavioral substitution between leisure time at home and effort at work. In equilibrium, residing at a location with a long commute affects the time available for leisure at home and therefore affects the trade-off between effort at work and risk of unemployment. This model implies an empirical relationship between expected commutes and labor market outcomes, which is tested using the Public Use Microdata sample of the 2000 U.S. Decennial Census. The empirical results suggest that efficiency wages operate primarily for blue collar workers, i.e. workers who tend to be in occupations that face higher levels of supervision. For this subset of workers, longer commutes imply higher levels of unemployment and higher wages, which are both consistent with shirking and leisure being substitutable.

Who's in Charge in the Inner City? The Conflict Between Efficiency and Equity in the Design of a Metropolitan Area

A circular metropolitan area consists of an inner city and a suburb. Households sort over the two jurisdictions based on public service levels and their costs of commuting to the metropolitan center. Using numerical simulations, we show (1) there typically exist two equilibria: one in which the poor form the majority in the inner city and the other in which the rich form the majority in the inner city; (2) there is an efficiency vs. equity trade-off as to which equilibrium is preferred; and (3) if the inner city contains only poor households, equity favors expanding the inner city to include rich households.

Prevalence of depressive symptoms in urban middle and high school Hispanic and African American students

This cross-sectional study examined the prevalence of depressive symptoms in urban Hispanic and African American middle and high school students (N=1,292) using data collected from a multi-component, multi-wave violence and substance use intervention program targeted at a large urban school district in Texas. Chi-square analysis was used to examine differences in race/ethnicity, gender, grade level and whether or not a student had been held back/repeated a grade in school. Univariate and multivariate logistic regression were used to analyze the association between depressive symptoms and demographic variables. Being female and being held back/repeating a grade was significantly associated with depressive symptoms in both univariate and multivariate analyses. Overall 16% of the students reported depressive symptoms; Hispanic youth had a higher prevalence of depressive symptoms (16.8%) than the African American youth (14.8%). Minority females and those who had been held back/repeated a grade reported a prevalence of 19.4% and 21.2%, respectively. Further research is needed to understand why Hispanic youth continue to report a higher prevalence of depressive symptoms than other minorities. Additionally research is required to further explore the association between academic performance and depressive symptoms in urban minorities, specifically the effect of being held back/repeating a grade.^

Psychosocial variables associated with sexual risk behavior among an urban seventh grade population

This dissertation examines the psychosocial factors associated with sexual risk behavior among low socio-economic, minority middle school students in a large urban school district in Houston, Texas and is presented in the form of three articles. Article One examines the association between knowledge, perceived risk of HIV/STD, and self-reported lifetime engagement in vaginal sex among seventh grade students. The purpose of Article Two is to examine the association between knowledge about condoms, condom use attitudes, perceived peer norms about condom use, condom use negotiation self-efficacy, condom use self-efficacy, condom use intentions and actual condom use among seventh grade middle school adolescents. Finally, Article Three examines the association between attitudes, perceived peer norms, refusal self-efficacy about sex, sexual and abstinence intentions among seventh grade adolescents. By providing a better understanding of factors influencing sexual intentions and sexual behaviors among this population, these articles will enable practitioners to develop effective evidence-based interventions to delay sexual initiation and prevent youth from engaging in risky sexual behaviors, including risk of HIV/STDs and unintended pregnancy.^

Tobacco use and related psychosocial risk factors among youth in urban India: Assessment of Project MYTRI follow-up surveys

Project MYTRI (Mobilizing Youth for Tobacco-Related Initiatives in India) was a large 2-year randomized school-based trial with a goal to reduce and prevent tobacco use among students in 6th and 8th grades in Delhi and Chennai in India (n=32 schools). Baseline analyses in 2004 showed that 6th grade students reported more tobacco use than 8 th grade students, opposite of what is typically observed in developed countries like the US. The present study aims to study differences in tobacco use and psychosocial risk factors between the 6th grade cohort and 8th grade cohort, in a compliant sub-sample of control students that were present at all 3 surveys from 2004-06. Both in 2004 and 2005, 6th grade cohort reported significantly greater prevalence of ever use of all tobacco products (cigarettes, bidis, chewing tobacco, any tobacco). These significant differences in ever use of any tobacco between cohorts were maintained by gender, city and socioeconomic status. The 6th grade cohort also reported significantly greater prevalence of current use of tobacco products (cigarettes, chewing tobacco, any tobacco) in 2004. Similar findings were observed for psychosocial risk factors for tobacco use, where the 6th grade cohort scored higher risk than 8th grade cohort on scales for intentions to smoke or chew tobacco and susceptibility to smoke or chew tobacco in 2004 and 2005, and for knowledge of health effects of tobacco in all three years.^ The evidence of early initiation of tobacco use in our 6th grade cohort in India indicates the need to target prevention programs and other tobacco control measures from a younger age in this setting. With increasing proportions of total deaths and lost DALYs in India being attributable to chronic diseases, addressing tobacco use among younger cohorts is even more critical. Increase in tobacco use among youth is a cause for concern with respect to future burden of chronic disease and tobacco-related mortality in many developing countries. Similarly, epidemiological studies that aim to predict future death and disease burden due to tobacco should address the early age at initiation and increasing prevalence rates among younger populations. ^

An empirical model to estimate the demand for primary care in urban settings

Objective. To measure the demand for primary care and its associated factors by building and estimating a demand model of primary care in urban settings.^ Data source. Secondary data from 2005 California Health Interview Survey (CHIS 2005), a population-based random-digit dial telephone survey, conducted by the UCLA Center for Health Policy Research in collaboration with the California Department of Health Services, and the Public Health Institute between July 2005 and April 2006.^ Study design. A literature review was done to specify the demand model by identifying relevant predictors and indicators. CHIS 2005 data was utilized for demand estimation.^ Analytical methods. The probit regression was used to estimate the use/non-use equation and the negative binomial regression was applied to the utilization equation with the non-negative integer dependent variable.^ Results. The model included two equations in which the use/non-use equation explained the probability of making a doctor visit in the past twelve months, and the utilization equation estimated the demand for primary conditional on at least one visit. Among independent variables, wage rate and income did not affect the primary care demand whereas age had a negative effect on demand. People with college and graduate educational level were associated with 1.03 (p < 0.05) and 1.58 (p < 0.01) more visits, respectively, compared to those with no formal education. Insurance was significantly and positively related to the demand for primary care (p < 0.01). Need for care variables exhibited positive effects on demand (p < 0.01). Existence of chronic disease was associated with 0.63 more visits, disability status was associated with 1.05 more visits, and people with poor health status had 4.24 more visits than those with excellent health status. ^ Conclusions. The average probability of visiting doctors in the past twelve months was 85% and the average number of visits was 3.45. The study emphasized the importance of need variables in explaining healthcare utilization, as well as the impact of insurance, employment and education on demand. The two-equation model of decision-making, and the probit and negative binomial regression methods, was a useful approach to demand estimation for primary care in urban settings.^

Is dating violence associated with substance use and sexual risk behaviors among urban, minority, middle school youth

Background. One in 4 adolescents reports some form of dating violence each year. Dating violence among high school adolescents has been linked with several morbidity issues. However, the association between dating violence and sexual risk and/or substance use among young adolescents has rarely been studied.^ Methods. Research hypotheses were tested using a secondary data analysis from a HIV, STI, pregnancy prevention intervention study for urban middle school students.^ Results. At baseline, 21% of youth reported experiencing physical ADV victimization, 48.2% reported non-physical victimization, and 52.6% report any victimization. After adjusting for race/ethnicity, gender, and age ever having sex, alcohol use, and illicit drug use were significantly associated with several forms of ADV.^ Conclusions. Dating violence appears to be associated with early initiation of sexual behavior, as well as alcohol and drug use. Few interventions address ADV among middle school youth. Early interventions that prevent dating violence are needed. ^

An investigation into the relationship between screen time, consumption of advertised foods, and physical activity among Texas 4th grade elementary school children

Background. The high prevalence of obesity among children has spurred creation of a list of possible causative factors, including the advertising of foods of minimal nutritional value, a decrease in physical activity, and increased media use. Few studies show prevalence rates of these factors among large cohorts of children. ^ Methods. Using data from the 2004-2005 School Physical Activity and Nutrition project (SPAN), a secondary analysis of 7907 4th-grade children (mean age 9.74 years) was conducted. In addition, a comic-book–based intervention that addressed advertised food consumption, physical activity, and media use was developed and evaluated using a pre-post test design among 4th-grade children in an urban school district. ^ Results. Among a cohort of 4th-grade children across the state of Texas, children who had more than 2 hours of video game or computer time the previous day were more than twice as likely to drink soda and eat candy or pastries. In addition, children who watched more than 2 hours of TV the previous day were more than three times as likely to consume chips, punch, soda, candy, frozen desserts, or pastries (AOR 3.41, 95% CI: 1.58, 7.37). A comic-book based intervention held great promise and acceptance among 4th-grade children. Outcome evaluation showed that while results moved in a positive direction, they were not statistically significant. ^ Conclusion. Statistically significant associations were found between screen time and eating various types of advertised food. The comic book intervention was widely accepted by the children exposed to it, and pre-post surveys indicated they moved constructs in a positive direction. Further research is needed to look at more specific ways in which children are exposed to TV, and the relationship of the TV viewing time with their consumption of advertised foods. In addition, researchers should look at comic book interventions more closely and attempt to utilize them in more in studies with a longer follow-up time. ^

Effects of congressional modernization laws on public access to innovative medical device technologies

The Federal Food and Drug Administration (FDA) and the Centers for Medicare and Medicaid (CMS) play key roles in making Class III, medical devices available to the public, and they are required by law to meet statutory deadlines for applications under review. Historically, both agencies have failed to meet their respective statutory requirements. Since these failures affect patient access and may adversely impact public health, Congress has enacted several “modernization” laws. However, the effectiveness of these modernization laws has not been adequately studied or established for Class III medical devices. ^ The aim of this research study was, therefore, to analyze how these modernization laws may have affected public access to medical devices. Two questions were addressed: (1) How have the FDA modernization laws affected the time to approval for medical device premarket approval applications (PMAs)? (2) How has the CMS modernization law affected the time to approval for national coverage decisions (NCDs)? The data for this research study were collected from publicly available databases for the period January 1, 1995, through December 31, 2008. These dates were selected to ensure that a sufficient period of time was captured to measure pre- and post-modernization effects on time to approval. All records containing original PMAs were obtained from the FDA database, and all records containing NCDs were obtained from the CMS database. Source documents, including FDA premarket approval letters and CMS national coverage decision memoranda, were reviewed to obtain additional data not found in the search results. Analyses were conducted to determine the effects of the pre- and post-modernization laws on time to approval. Secondary analyses of FDA subcategories were conducted to uncover any causal factors that might explain differences in time to approval and to compare with the primary trends. The primary analysis showed that the FDA modernization laws of 1997 and 2002 initially reduced PMA time to approval; after the 2002 modernization law, the time to approval began increasing and continued to increase through December 2008. The non-combined, subcategory approval trends were similar to the primary analysis trends. The combined, subcategory analysis showed no clear trends with the exception of non-implantable devices, for which time to approval trended down after 1997. The CMS modernization law of 2003 reduced NCD time to approval, a trend that continued through December 2008. This study also showed that approximately 86% of PMA devices do not receive NCDs. ^ As a result of this research study, recommendations are offered to help resolve statutory non-compliance and access issues, as follows: (1) Authorities should examine underlying causal factors for the observed trends; (2) Process improvements should be made to better coordinate FDA and CMS activities to include sharing data, reducing duplication, and establishing clear criteria for “safe and effective” and “reasonable and necessary”; (3) A common identifier should be established to allow tracking and trending of applications between FDA and CMS databases; (4) Statutory requirements may need to be revised; and (5) An investigation should be undertaken to determine why NCDs are not issued for the majority of PMAs. Any process improvements should be made without creating additional safety risks and adversely impacting public health. Finally, additional studies are needed to fully characterize and better understand the trends identified in this research study.^

A look at parent-adolescent processes and adolescent sexual intentions among urban, minority, middle school youth

Background. The United States continues to have the highest rates in teenage pregnancy among industrialized nations and approximately 46% of high school students engaged in sex by the time they graduated. Various family adolescent processes (family connectedness, perceived parental beliefs about sex, parent-child communication about sex) have been linked to adolescent sexual behavior. However, the association between family adolescent and adolescent sexual intentions has not often been studied in middle school minority youth.^ Methods. Research hypotheses were tested using a secondary data analysis from a HIV, STI, and pregnancy prevention program for urban middle school students.^ Results. At baseline, 77% of students reported low intentions to engage in vaginal or oral sex within a year and 87% reported they would use a condom if having sex within the next 3 months. After adjusting for gender, age, and race/ethnicity, family connectedness and perceived parental beliefs about sex were significantly associated with vaginal and oral sex intentions. Only perceived parental beliefs was associated with condom use intentions. ^ Conclusions. Family adolescent processes appear to be associated with adolescents’ intentions regarding sex and condom use. Early interventions are needed that take into account the importance of healthy, supportive parent-adolescent relationships and encourage parents to share their beliefs about sex to adolescents before the onset of sexual activity. ^

Comparison of financial trends in small rural and urban hospitals in Texas, 1983--1985

The purpose of this study was to compare the financial performance of small rural hospitals to that of small urban hospitals in Texas. Hospital-specific and environmental factors were studied as control variables.^ Small rural hospitals were found to be financially stronger on measures of liquidity but weaker on measures of profitability. Small urban hospitals performed better on measures of profitability and long-range solvency. When all measures in the five dimensions of financial performance were analyzed, no significant difference was found between the two groups of hospitals. None of the control variables included in the study was significantly associated with financial performance both for rural and urban hospitals. Conclusions were that small rural hospitals in Texas are experiencing a deterioration in financial condition but small, rural hospitals are not doing any worse than small urban hospitals; and that the financial hardship which rural hospitals suffer may be inherent in the nature of the institutions themselves, and not as a result of their smallness nor their rural settings. ^

Information sources influencing urban Mexican-American women's cancer screening participation

Breast and cervical cancer, though less common in Mexican-American than in Anglo women, are more likely to go undetected in Mexican-American women, leaving them more vulnerable to advanced disease and death. Although highly effective screening tests--the Pap smear and the mammogram--can detect these cancers early, many Mexican-American women do not regularly undergo these preventive screening tests.^ To explore the differential influence of encouraging sources of health information, this investigation examined the relationship between encouragement from a "peer"--husband or partner, child or children, other family members, or close friends--and a "health professional"--a doctor, a nurse, or another health professional--on Mexican-American women's cancer screening intentions and behaviors. Furthermore, this research explored whether the sources' influence on cancer screening intentions and behaviors differed depending on level of acculturation.^ One thousand seven hundred eleven surveys of Mexican-American women were analyzed to identify the source that most effectively encourages these women to participate in cancer screening. The data provided evidence that health professionals strongly influenced this population's cancer screening intentions and behaviors. Evidence for peer influence was also found; however, it was usually weaker, and, in some cases, negligible. Peer encouragement was related to Pap test behaviors and mammogram intentions, but not to Pap test intentions or mammogram behaviors. Consistently, women reported greater intentions and screening behaviors when encouraged from a health professional than from a peer. Acculturation was not found to be a modifying variable related to the relationship between sources of information and Pap test or mammogram intentions and behaviors.^ Because health professionals were identified as strongly influencing both intentions and behaviors for Pap tests and mammograms, further efforts should be undertaken to urge them to encourage their clients to obtain cancer screening. Failure to provide this encouragement leads to missed opportunities. Enlisting support from peers also may help to increase cancer screening participation in urban Mexican-American women; however, the consistently greater intentions and behaviors related to a health professional's encouragement indicated the greater power of the latter. ^

Pediatric asthma incidence in Texas and associations with ambient ozone levels in an urban area an analysis using Medicaid claims data

Few recent estimates of childhood asthma incidence exist in the literature, although the importance of incidence surveillance for understanding asthma risk factors has been recognized. Asthma prevalence, morbidity and mortality reports have repeatedly shown that low-income children are disproportionately impacted by the disease. The aim of this study was to demonstrate the utility of Medicaid claims data for providing statewide estimates of asthma incidence. Medicaid Analytic Extract (MAX) data for Texas children ages 0-17 enrolled in Medicaid between 2004 and 2007 were used to estimate incidence overall and by age group, gender, race and county of residence. A 13+ month period of continuous enrollment was required in order to distinguish incident from prevalent cases identified in the claims data. Age-adjusted incidence of asthma was 4.26/100 person-years during 2005-2007, higher than reported in other populations. Incidence rates decreased with age, were higher for males than females, differed by race, and tended to be higher in rural than urban areas. With this study, we were able to demonstrate the utility of MAX data for estimating asthma incidence, and create a dataset of incident cases to use in further analysis. ^ In subsequent analyses, we investigated a possible association between ambient air pollutants and incident asthma among Medicaid-enrolled children in Harris County Texas between 2005 and 2007. This population is at high risk for asthma, and living in an area with historically poor air quality. We used a time-stratified case-crossover design and conditional logistic regression to calculate odds ratios, adjusted for weather variables and aeroallergens, to assess the effect of increases in ozone, NO2 and PM2.5 concentrations on risk of developing asthma. Our results show that a 10 ppb increase in ozone was significantly associated with asthma during the warm season (May-October), with the strongest effect seen when a 6-day cumulative lag period was used to compute the exposure metric (OR=1.05, 95% CI, 1.02–1.08). Similar results were seen for NO2 and PM 2.5 (OR=1.07, 95% CI, 1.03–1.11 and OR=1.12, 95% CI, 1.03–1.22, respectively). PM2.5 also had significant effects in the cold season (November-April), 5-day cumulative lag: OR=1.11, 95% CI, 1.00–1.22. When compared with children in the lowest quartile of O3 exposure, the risk for children in the highest quartile was 20% higher. This study indicates that these pollutants are associated with newly-diagnosed childhood asthma in this low-income urban population, particularly during the summer months. ^

Teaching safety at a summer camp: Evaluation of a children's fire safety curriculum in an urban community setting

Objectives: The purpose of this study was to evaluate the effectiveness of the Danger Rangers Fire Safety Curriculum in increasing the fire safety knowledge of low-income, minority children in pre-kindergarten to third grade in Austin, TX during a summer day camp in 2007.^ Methods: Data was collected from child participants via teacher and researcher administered tests at pretest, posttest (immediately after the completion of the fire safety module), and at a 3 week follow-up to asses retention. In addition, a self-administered questionnaire was collected from parents pre- and post-intervention to assess home-related fire/burn risk factors. Paired t-tests were conducted using STATA 12.0 to evaluate pretest, posttest, and retention test mean scores as well as mean fire safety rules listed by grade group. McNemar's test was used to determine if there was a difference in fire-related risk factors as reported by the parents of the participants before and after the intervention. Only those who had paired data for the tests/surveys being compared were included in the analysis.^ Results: The first/second grade group and the third grade group scored significantly higher on fire safety knowledge on the posttest compared to the pretest (p<0.0001 for both groups). However, there was no significant change in knowledge scores for the pre-kindergarten to kindergarten group (p=0.14). Among the first/second grade group, knowledge levels did not significantly decline between the posttest and retention test (p=0.25). However, the third grade group had significantly lower fire safety knowledge scores on the retention test compared to the posttest (p<0.001). A similar increase was seen in the amount of fire safety rules listed after the intervention (p<0.0001 between pre and posttest for both the first/second grade and third grade groups), with no decline from the posttest to the retention test (p=0.50) for the first/second grade group, but a significant decline in the third grade group (p=0.001). McNemar's chi-square test showed a significant increase in the percentage of participants' parents reporting smoke detector testing on a regular basis and having a fire escape plan for their family after the intervention (p=0.01 and p<0.0001, respectively). However, there was no significant change in the frequency of reports of the child playing in the kitchen while the parent cooks or the house/apartment having a working smoke detector.^ Conclusion: We found that general fire safety knowledge improved and the number of specific fire safety rules increased among the first to third grade children who participated in the Danger Rangers fire safety program. However, it did not significantly increase general fire safety knowledge among the pre-k/k group. This study also showed that a program targeted towards children has the potential to influence familial risk factors by proxy. The Danger Rangers Fire Safety Curriculum should be further evaluated by conducting a randomized controlled trial, using valid measures that assess fire safety attitudes, beliefs, behaviors, as well as fire/burn related outcomes.^