A space-time analysis of reported shigellosis and salmonellosis cases in Texas from 2000 to 2004

Background. The purpose of this study was to describe the risk factors and demographics of persons with salmonellosis and shigellosis and to investigate both seasonal and spatial variations in the occurrence of these infections in Texas from 2000 to 2004, utilizing time series analyses and the geographic information system digital mapping methods. ^ Methods. Spatial Analysis: MapInfo software was used to map the distribution of age-adjusted rates of reported shigellosis and salmonellosis in Texas from 2000–2004 by zip codes. Census data on above or below poverty level, household income, highest level of educational attainment, race, ethnicity, and urban/rural community status was obtained from the 2000 Decennial Census for each zip code. The zip codes with the upper 10% and lower 10% were compared using t-tests and logistic regression to determine whether there were any potential risk factors. ^ Temporal analysis. Seasonal patterns in the prevalence of infections in Texas from 2000 to 2003 were determined by performing time-series analysis on the numbers of cases of salmonellosis and shigellosis. A linear regression was also performed to assess for trends in the incidence of each disease, along with auto-correlation and multi-component cosinor analysis. ^ Results. Spatial analysis: Analysis by general linear model showed a significant association between infection rates and age, with young children aged less than 5 and those aged 5–9 years having increased risk of infection for both disease conditions. The data demonstrated that those populations with high percentages of people who attained a higher than high school education were less likely to be represented in zip codes with high rates of shigellosis. However, for salmonellosis, logistic regression models indicated that when compared to populations with high percentages of non-high school graduates, having a high school diploma or equivalent increased the odds of having a high rate of infection. ^ Temporal analysis. For shigellosis, multi-component cosinor analyses were used to determine the approximated cosine curve which represented a statistically significant representation of the time series data for all age groups by sex. The shigellosis results show 2 peaks, with a major peak occurring in June and a secondary peak appearing around October. Salmonellosis results showed a single peak and trough in all age groups with the peak occurring in August and the trough occurring in February. ^ Conclusion. The results from this study can be used by public health agencies to determine the timing of public health awareness programs and interventions in order to prevent salmonellosis and shigellosis from occurring. Because young children depend on adults for their meals, it is important to increase the awareness of day-care workers and new parents about modes of transmission and hygienic methods of food preparation and storage. ^

Social support, health status and health services utilization among the noninstitutionalized elderly: An analysis of the Supplement on Aging to the 1984 national health interview survey

The association between Social Support, Health Status, and Health Services Utilization of the elderly, was explored based on the analysis of data from the Supplement on Aging to the National Health Interview Survey, 1984 (N = 11,497) using a modified framework of Aday and Andersen's Expanded Behavioral Model. The results suggested that Social Support as operationalized in this study was an independent determinant of the use of health services. The quantity of social activities and the use of community services were the two most consistent determinants across different types of health services use.^ The effects of social support on the use of health services were broken down into three components to facilitate explanations of the mechanisms through which social support operated. The Predisposing and Enabling component of Social Support had independent, although not uniform, effects on the use of health services. Only slight substitute effects of social support were detected. These included the substitution of the use of senior centers for longer stay in the hospital and the substitution of help with IADL problems for the use of formal home care services.^ The effect of financial support on the use of health services was found to be different for middle and low income populations. This differential effect was also found for the presence of intimate networks, the frequencies of interaction with children and the perceived availability of support among urban/rural, male/female and white/non-white subgroups.^ The study also suggested that the selection of appropriate Health Status measures should be based on the type of Health Services Utilization in which a researcher is interested. The level of physical function limitation and role activity limitation were the two most consistent predictors of the volume of physician visits, number of hospital days, and average length of stay in the hospital during the past year.^ Some alternative hypotheses were also raised and evaluated, when possible. The impacts of the complex sample design, the reliability and validity of the measures and other limitations of this analysis were also discussed. Finally, a revised framework was proposed and discussed based on the analysis. Some policy implications and suggestions for future study were also presented. ^

Factors associated with home health care costs

Characteristics of Medicare-certified home health agencies in Texas and the contributions of selected agency characteristics on home health care costs were examined. Cost models were developed and estimated for both nursing and total visit costs using multiple regression procedures. The models included home health agency size, profit status, control, hospital-based affiliation, contract-cost ratio, service provision, competition, urban-rural input-price differences, and selected measures of patient case-mix. The study population comprised 314 home health agencies in Texas that had been certified at least one year on July, 1, 1986. Data for the analysis were obtained from Medicare Cost Reports for fiscal year ending between July 1, 1985 to June 30, 1986.^ Home health agency size, as measured by the logs of nursing and total visits, has a statistically significant negative linear relationship with nursing visit and total visit costs. Nursing and total visit costs decrease at a declining rate as size increases. The size-cost relationship is not altered when controlling for any other agency characteristic. The number of visits per patient per year, a measure of patient case-mix, is also negatively related to costs, suggesting that costs decline with care of chronic patients. Hospital-based affiliation and urban location are positively associated with costs. Together, the four characteristics explain 19 percent of the variance in nursing visit costs and 24 percent of the variance in total visit costs.^ Profit status and control, although correlated with other agency characteristics, exhibit no observable effect on costs. Although no relationship was found between costs and competition, contract cost ratio, or the provision on non-reimburseable services, no conclusions can be made due to problems with measurement of these variables. ^

An assessment of risk of osteogenic sarcoma from exposure to radium

The etiology of the vast majority of osteosarcoma deaths has not been explained. A possible explanation might be lifetime ingestion of radium from environmental sources which might give rise to differential risk. This study was an effort toward understanding the role of naturally occurring radium in the etiology of bone cancer. Furthermore, there was an interest in the interaction of between radionuclides and selenium; the latter believed to be a potential anticarcinogen.^ Two approaches were used to evaluate the association between environmental radium, selenium and osteogenic sarcoma: (1) spatial and temporal patterns of osteogenic sarcoma mortality in Texas were described for the period from 1969 to 1988; and (2) a case-control study was performed using 974 osteosarcoma deaths and category-matched controls selected from other deaths to evaluate the association between this disease and residency history as an indirect measure of radium and selenium exposures.^ Analyses and comparison of mortality in a population exposed to regions of elevated levels of radium 226,228 and elevated levels of selenium in drinking water with those in a matched control population have resulted in three observations: (1) there appeared to be a slight protective effect for residing in areas high in radium; (2) there were no significant differences between cases and controls when observed for length of residence or residence in urban/rural regions of high or low radium; and (3) although regions high in selenium appeared to have a decreased risk for bone cancer and urban areas in regions of elevated selenium showed an increased risk of bone cancer, these differences were not significant. ^

Social integration, health behaviors and health status among Mexican-American women in the *southwestern United States

Using the Hispanic Health and Nutrition Examination Survey (HHANES), this research examined several health behaviors and the health status of Mexican American women. This study focused on determining the relative impact of social contextual factors: age, socioeconomic status, quality of life indicators, and urban/rural residence on (a) health behaviors (smoking, obesity and alcohol use) and (b) health status (physician's assessment of health status, subject's assessment of health status and blood pressure levels). In addition, social integration was analyzed. The social integration indicators relate to an individual's degree of integration within his/her social group: marital status, level of acculturation (a continuum of traditional Mexican ways to dominant U.S. cultural ways), status congruency, and employment status. Lastly, the social contextual factors and social integration indicators were examined to identify those factors that contribute most to understanding health behaviors and health status among Mexican American women.^ The study found that the social contextual factors and social integration indicators proved to be important concepts in understanding the health behaviors. Social integration, however, did not predict health status except in the case of the subject's assessment of health status. Age and obesity were the strongest predictors of blood pressure. The social contextual factors and obesity were significant predictors of the physician's assessment of health status while acculturation, education, alcohol use and obesity were significant predictors of the subject's assessment of health status. ^

Hypertension control and related variables among urban and rural adults in Taiwan

Literature on hypertension treatment has demonstrated that a healthy life style is one of the best strategies for hypertension control. In exploring the mechanisms of behavioral change for hypertension control, a comprehensive study based on the Transtheoretical Model was carried out in Taiwan during the summer of 2000 with a sample of 350 hypertensive adults living in Taipei urban and rural areas. ^ The relationships among stages of change, processes of change and demographic factors were analyzed for six health behaviors—low fat food consumption, alcohol use, smoking, physical activity, weight control, and routine blood pressure checkups. In addition, differences were assessed between urban and rural populations in changing their behavior for hypertension control. ^ The results showed that rural populations had more difficulties than urban populations in avoiding smoking and engaging in physical activity, and the processes of change being used by urban populations were significantly greater than rural populations. The study findings support a strong association between processes and stages of change. ^ Individuals who use more processes of change will be more inclined to move from precontemplation stage to maintenance stage. Counterconditioning, which is the substitution of alternatives for the problem behaviors, in this study, significantly helped people to change diet, engage in physical activity, and check blood pressure regularly. For example, counterconditioning is eating more vegetables instead of meat, or engaging in physical activity as a time to relax rather than another task to accomplish. ^ In addition, self-reevaluation was the most important process for helping people to engage in physical activity; and social liberation was the most important process for changing diet behavior. The findings in this study may be applied to improve health behaviors among rural populations with low income and low education; however, at the same time, the obesity problems among urban populations should be prevented to control hypertension in Taiwan. ^

Crack and powder cocaine federal legislation: A sentencing disparity and potential for policy improvement

Since its introduction into the United States in the 1980s, crack cocaine has been a harsh epidemic that has taken its toll on a countless number of people. This highly addictive, cheap and readily available drug of abuse has permeated many demographic sectors, mostly in low income, lesser educated, and urban communities. This epidemic of crack cocaine use in inner city areas across the Unites States has been described as an expression of economic marginality and “social suffering” coupled with the local and international forces of drug market economies (Agar 2003). As crack cocaine is a derivative of cocaine, it utilizes the psychoactive component of the drug, but delivers it in a much stronger, quicker, and more addictive fashion. This, coupled with its ready availability and cheap price has allowed for users to not only become very addicted very quickly, but to be subject to the stringent and sometimes unequal or inconsistent punishments for possession and distribution of crack-cocaine. ^ There are many public health and social ramifications from the abuse of crack-cocaine, and these epidemics appear to target low income and minority groups. Public health issues relating to the physical, mental, and economic strain will be addressed, as well as the direct and indirect effects of the punishments that come as a result of the disparity in penalties for cocaine and crack-cocaine possession and distribution. ^ Three new policies have recently been introduced into the United Stated Congress that actively address the disparity in sentencing for drug and criminal activities. They are, (1) Powder-Crack Cocaine Penalty Equalization Act of 2009, (HR 18, 111th Cong. 2009), (2) The Drug Sentencing Reform and Cocaine Kingpin Trafficking Act of 2009, (HR 265, 111th Cong. 2009) and (3) The Justice Integrity Act of 2009, (111th Cong. 2009). ^ Although they have only been initiated, if passed, they have potential to not only eliminate the crack-cocaine disparity, but to enact laws that help those affected by this epidemic. The final and overarching goal of this paper is to analyze and ultimately choose the ideal policy that would not only eliminate the cocaine and crack disparity regardless of current or future state statutes, but will provide the best method of rehabilitation, prevention, and justice. ^

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. ^

AN ANALYSIS OF THE RELATIVE INFLUENCE OF RACE, INCOME, EDUCATION, AND FOOD STAMP PROGRAM PARTICIPATION/NONPARTICIPATION ON THE FOOD AND NUTRIENT CONSUMPTION OF A NORTH FLORIDA URBAN CLINIC POPULATION IN CONJUNCTION WITH A SURVEY OF NUTRITION RELATED HABITS AND ATTITUDES

The relative influence of race, income, education, and Food Stamp Program participation/nonparticipation on the food and nutrient intake of 102 fecund women ages 18-45 years in a Florida urban clinic population was assessed using the technique of multiple regression analysis. Study subgroups were defined by race and Food Stamp Program participation status. Education was found to have the greatest influence on food and nutrient intake. Race was the next most influential factor followed in order by Food Stamp Program participation and income. The combined effect of the four independent variables explained no more than 19 percent of the variance for any of the food and nutrient intake variables. This would indicate that a more complex model of influences is needed if variations in food and nutrient intake are to be fully explained.^ A socioeconomic questionnaire was administered to investigate other factors of influence. The influence of the mother, frequency and type of restaurant dining, and perceptions of food intake and weight were found to be factors deserving further study.^ Dietary data were collected using the 24-hour recall and food frequency checklist. Descriptive dietary findings indicated that iron and calcium were nutrients where adequacy was of concern for all study subgroups. White Food Stamp Program participants had the greatest number of mean nutrient intake values falling below the 1980 Recommended Dietary Allowances (RDAs). When Food Stamp Program participants were contrasted to nonparticipants, mean intakes of six nutrients (kilocalories, calcium, iron, vitamin A, thiamin, and riboflavin) were below the 1980 RDA compared to five mean nutrient intakes (kilocalories, calcium, iron, thiamin and riboflavin) for the nonparticipants. Use of the Index of Nutritional Quality (INQ), however, revealed that the quality of the diet of Food Stamp Program participants per 1000 kilocalories was adequate with exception of calcium and iron. Intakes of these nutrients were also not adequate on a 1000 kilocalorie basis for the nonparticipant group. When mean nutrient intakes of the groups were compared using Student's t-test oleicacid intake was the only significant difference found. Being a nonparticipant in the Food Stamp Program was found to be associated with more frequent consumption of cookies, sweet rolls, doughnuts, and honey. The findings of this study contradict the negative image of the Food Stamp Program participant and emphasize the importance of education. ^

The Relationship of Provincial Economic Level and Child Injury Mortality in Thailand: A Cross-Sectional Analysis in a Middle Income Country

The objective of this cross-sectional study was to examine the relationship of provincial economic development indices with incidences of child injury mortality in Thailand from 1999 - 2001. All injury deaths among children age 1-14 years were included. The independent variables included gross provincial product per capita (GPP/c), poverty and inequality indices, material and social deprivation indices, population in rural/ urban areas, and migration. Due to multicollinearity of such variables, the 76 provinces were categorized by GPP/c quartile, and means of overall injury, drowning, and transport-related mortality rates were compared among quartile groups. Spearman’s rho correlation between GPP/c and injury mortality rates was also performed. Finally, factor analysis was employed to create a set of factors to be treated as uncorrelated variables and stepwise multiple regression was carried out for the effects of the factors on injury mortality rates. A significant direct relationship was observed between GPP/c and overall injury mortality among children age 1-4 years, and 10-14 year-olds of both genders. Drowning was the main cause of this relationship among children age 1-4 years, and transport-related injury was the principle cause among children age 10-14 years. Conversely, provinces with lower GPP/c experienced higher injury mortality rates among school-age children 5-9 years old for both genders, mostly due to drowning. Factor analysis, and multiple regression results confirmed the relationships between economic development and injury mortality rates. These findings revealed that economic development had an adverse impact on injury-related mortality among children 1 to 4 and 10 to14 in Thailand.

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. ^

An empirical examination of relative profitability in the nursing facility industry between ownership form and regionality in the state of Texas

The purpose of this research is to examine the relative profitability of the firm within the nursing facility industry in Texas. An examination is made of the variables expected to affect profitability and of importance to the design and implementation of regulatory policy. To facilitate this inquiry, specific questions addressed are: (1) Do differences in ownership form affect profitability (defined as operating income before fixed costs)? (2) What impact does regional location have on profitability? (3) Do patient case-mix and access to care by Medicaid patients differ between proprietary and non-profit firms and facilities located in urban versus rural regions, and what association exists between these variables and profitability? (4) Are economies of scale present in the nursing home industry? (5) Do nursing facilities operate in a competitive output market characterized by the inability of a single firm to exhibit influence over market price?^ Prior studies have principally employed a cost function to assess efficiency differences between classifications of nursing facilities. The inherent weakness in this approach is that it only considers technical efficiency. Not both technical and price efficiency which are the two components of overall economic efficiency. One firm is more technically efficient compared to another if it is able to produce a given quantity of output at the least possible costs. Price efficiency means that scarce resources are being directed towards their most valued use. Assuming similar prices in both input and output markets, differences in overall economic efficiency between firm classes are assessed through profitability, hence a profit function.^ Using the framework of the profit function, data from 1990 Medicaid Costs Reports for Texas, and the analytic technique of Ordinary Least Squares Regression, the findings of the study indicated (1) similar profitability between nursing facilities organized as for-profit versus non-profit and located in urban versus rural regions, (2) an inverse association between both payor-mix and patient case-mix with profitability, (3) strong evidence for the presence of scale economies, and (4) existence of a competitive market structure. The paper concludes with implications regarding reimbursement methodology and construction moratorium policies in Texas. ^

Racial and ethnic disparities in diabetes mellitus and hypertension: Influence of income and insurance status in a cross-sectional study of the United States

Racial/ethnic disparities in diabetes mellitus (DM) and hypertension (HTN) have been observed and explained by socioeconomic status (education level, income level, etc.), screening, early diagnosis, treatment, prognostic factors, and adherence to treatment regimens. To the author's knowledge, there are no studies addressing disparities in hypertension and diabetes mellitus utilizing Hispanics as the reference racial/ethnic group and adjusting for sociodemographics and prognostic factors. This present study examined racial/ethnic disparities in HTN and DM and assessed whether this disparity is explained by sociodemographics. To assess these associations, the study utilized a cross-sectional design and examined the distribution of the covariates for racial/ethnic group differences, using the Pearson Chi Square statistic. The study focused on Non-Hispanic Blacks since this ethnic group is associated with the worst health outcomes. Logistic regression was used to estimate the prevalence odds ratio (POR) and to adjust for the confounding effects of the covariates. Results indicated that except for insurance coverage, there were statistically significant differences between Non-Hispanic Blacks and Non-Hispanic Whites, as well as Hispanics with respect to study covariates. In the unadjusted logistic regression model, there was a statistically significant increased prevalence of hypertension among Non-Hispanic Blacks compared to Hispanics, POR 1.36, 95% CI 1.02-1.80. Low income was statistically significantly associated with increased prevalence of hypertension, POR 0.38, 95% CI 0.32-0.46. Insurance coverage, though not statistically significant, was associated with an increase in the prevalence of hypertension, p>0.05. Concerning DM, Non-Hispanic Blacks were more likely to be diabetic, POR 1.10, 95% CI 0.85-1.47. High income was statistically significantly associated with decreased prevalence of DM, POR 0.47, 95% CI 0.39-0.57. After adjustment for the relevant covariates, the racial disparities between Hispanics and Non-Hispanic Blacks in HTN was removed, adjusted prevalence odds (APOR) 1.21, 95% CI 0.88-1.67. In this sample, there was racial/ethnic disparity in hypertension but not in diabetes mellitus between Hispanics and Non-Hispanic Blacks, with disparities in hypertension associated with socioeconomic status (family income, education, marital status) and also by alcohol, physical activity and age. However, race, education and BMI as class variables were statistically significantly associated with hypertension and diabetes mellitus p<0.0001. ^

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.^

Expanding cities and expanding waistlines: Urban sprawl and its impact on obesity, how the adoption of smart growth statutes can build healthier and more active communities

For decades, American towns and cities have expanded from their established cores into the surrounding rural areas. U.S. population has grown but the land that we use has grown at an even faster pace, and our country has now become a largely suburban nation. Americans moved and continue to move out to the suburbs in search of better lives – for clean and healthy living, for larger homes, and for better resources. In many ways and for many Americans, the suburban lifestyle has been a great success. However, there are some unintended public health consequences of urban sprawl that must be recognized. As most Americans no longer walk or bicycle, increasingly sedentary lifestyles now contribute to greater levels of obesity, diabetes and other associated chronic diseases. This thesis reviewed the impacts of urban sprawl on the public's health specifically, as sprawl relates to decreased physical activity rates and increased obesity rates. The health effects and their connection with sprawl were identified, and available evidence was reviewed. Finally, this thesis described legal and policy solutions for addressing the health effect through improving the design of our built environment and by recommending that governments adopt and implement Smart Growth statutes that incorporate a public health component and require public health involvement. ^