993 resultados para Biology, Biostatistics|Mathematics|Statistics|Health Sciences, Public Health
Resumo:
This research study was conducted as a descriptive study of prenatal care experiences of women enrolled in public and private managed care programs. The study's aim was to describe the demographic characteristics of the women in the study and to analyze and compare their prenatal care experiences. ^ The objective of this study was to examine the research question: Do pregnant women enrolled in Medicaid Managed Care receive the same level of care as women enrolled in other Managed Care Programs in Harris County, Texas? ^ The study population was a convenience sample of pregnant women enrolled in managed care programs who presented to one of the two hospital study sites for delivery of their infant. The study utilized a self administered survey to measure adequacy and content of prenatal care received by the women during this pregnancy. Adequacy of prenatal care utilization was determined based on the Kessner Index criteria of timing of initiation of care and number of visits. Content of care was measured by the number of different medical services the women reported they had received and the number of health information topics the women reported on which they had received information. Demographic characteristics were described with univariate and bivariate statistics of frequencies and cross tabulations. Associations were evaluated using measures of linear correlations. ^ Results from the study showed there is an association between enrollment in Medicaid Managed Care (public) and prenatal care received compared to women enrolled in other Managed Care Programs (private). The results were derived from statistical tests on data the postpartum women gave when they completed the self-administered survey. Provider type was a moderate predictor of quality and quantity of prenatal care. The results also indicate that in the study population, minority ethnicity, income and lower educational status were associated with intermediate and inadequate prenatal care. ^
Resumo:
This study has the purpose of determining the barriers and facilitators to nurses' acceptance of the Johnson and Johnson Protectiv®* Plus IV catheter safety needle device and implications for needlestick injuries at St. Luke's Episcopal Hospital, Houston, Texas. A one-time cross-sectional survey of 620 responding nurses was conducted by this researcher during December, 2000. The study objectives were to: (1) describe the perceived (a) organizational and individual barriers and facilitators and (b) acceptance of implementation of the IV catheter device; (2) examine the relative importance of these predictors; (3) describe (a) perceived changes in needlestick injuries after implementation of the device; (b) the reported incidence of injuries; and (c) the extent of underreporting by nurses; and (4) examine the relative importance of (a) the preceding predictors and (b) acceptance of the device in predicting perceived changes in needlestick injuries. Safety climate and training were evaluated as organizational factors. Individual factors evaluated were experience with the device, including time using it and frequency of use, and background information, including nursing unit, and length of time as a nurse in this hospital and in total nursing career. The conceptual framework was based upon the safety climate model. Descriptive statistics and multiple and logistic regression were utilized to address the study objectives. ^ The findings showed widespread acceptance of the device and a strong perception that it reduced the number of needlesticks. Acceptance was notably predicted by adequate training, appropriate time between training and device use, solid safety climate, and short length of service, in that order. A barrier to acceptance was nurses' longtime of use of previous needle technologies. Over four-fifths of nurses were compliant in always using the device. Compliance had two facilitators: length of time using device and, to a lesser extent, safety climate. Rates of compliance tended to be lower among nurses in units in which the device was frequently used. ^ High quality training and an atmosphere of caring about nurse safety stand out as primary facilitators that other institutions would need to adopt in order to achieve maximum success in implementing safety programs involving utilization of new safety devices. ^
Resumo:
Although Pap screening has decreased morbidity and mortality from cervical cancer, reported statistics indicate that among ethnic groups, Hispanic women are one of the least likely to follow screening guidelines. Human papillomavirus (HPV), a major risk factor for cervical cancer, as well as pre-cancerous lesions, may be detected by early Pap screening. With a reported 43% prevalence of HPV infection in college women, regular Pap screening is important. The purpose of this descriptive, cross-sectional survey was to examine self-reported cervical cancer screening rates in a target population of primarily Mexican-American college women, and to discover if recognized correlates for screening behavior explained differences in screening rates between this and two other predominant groups on the University of Houston Downtown campus, non-Hispanic white and African-American. The sample size consisted of 613 women recruited from summer 2003 classes. A survey, adapted from an earlier El Paso study, and based on constructs of the Health Belief Model (HBM), was administered to women ages 18 and older. It was found that although screening rates were similar across ethnic groups, overall, the Hispanic group obtained screening less frequently, though this did not reach statistical significance. However, a significant difference in lower screening rates was found in Mexican American women ages <25. Additionally, of the predicted correlates, the construct of perceived barriers from the HBM was most significant for the Mexican American group for non-screening. For all groups, knowledge about cervical cancer was negatively correlated with ever obtaining Pap screening and screening within the past year. This implies that if health counseling is given at the time of women's screening visits, both adherence to appropriate screening intervals and risk factor avoidance may be more likely. Studies such as these are needed to address both screening behaviors and likelihood of follow-up for abnormal results in populations of multicultural, urban college women. ^
Resumo:
Retinoid therapy has been successful for the treatment of skin squamous cell carcinoma (SCC). A suppression of the predominant retinoid X receptor expressed in skin, retinoid X receptor α (RXRα), has been reported in skin SCC. These observations have led to the hypothesis that retinoid receptor loss contributes to the tumorigenic phenotype of epithelial cancers. To test this hypothesis, the RXRα gene was mapped in order to generate a targeting construct. Additionally the transcriptional regulation of the human RXRα a gene in keratinocytes was characterized after identifying the transcription initiation sites, the promoter, and enhancer regions of this gene. The structure is highly conserved between human and mouse. A nontumorigenic human skin-derived cell line called near diploid immortalized keratinocytes (NIKS) has the advantage of growing as organotypic raft cultures, under physiological conditions closely resembling in-vivo squamous stratification. We have exploited the raft culture technique to develop an in-vitro model for skin SCC progression that includes the NIKS cells, HaCaT cells, a premalignant cell line, and SRB 12-p9 cells, a tumorigenic SCC skin cell line. The differentiation, proliferation and nuclear receptor ligand response characteristics of this system were studied and significant and novel results were obtained. RXRs are obligate heterodimerization partners with many of the nuclear hormone receptors, including retinoic acid receptors (RARs), vitamin D3 receptors (VDR), thyroid hormone receptors (T3 R) and peroxisome proliferator activate receptors (PPARs), which are all known to be active in skin. Treatment of the three cell lines in raft culture with the RXR specific ligand BMS649, BMS961 (RARγ-specific), vitamin D3 (VDR ligand), thryoid hormone (T3R ligand) and clofibrate (PPARa ligand), and the combination of BMS649 with each of the 4 receptor partner ligands, resulted in distinct effects on differentiation, proliferation and apoptosis. The effects of activation of RXRs in each of the four-receptor pathways; in the context of skin SCC progression, with an emphasis on the VDR/RXR pathway, are discussed. These studies will lead to a better understanding of RXRα action in human skin and will help determine its role in SCC tumorigenesis, as well as its potential as a target for the prevention, treatment, and control of skin cancer. ^
Resumo:
Background. Diabetes places a significant burden on the health care system. Reduction in blood glucose levels (HbA1c) reduces the risk of complications; however, little is known about the impact of disease management programs on medical costs for patients with diabetes. In 2001, economic costs associated with diabetes totaled $100 billion, and indirect costs totaled $54 billion. ^ Objective. To compare outcomes of nurse case management by treatment algorithms with conventional primary care for glycemic control and cardiovascular risk factors in type 2 diabetic patients in a low-income Mexican American community-based setting, and to compare the cost effectiveness of the two programs. Patient compliance was also assessed. ^ Research design and methods. An observational group-comparison to evaluate a treatment intervention for type 2 diabetes management was implemented at three out-patient health facilities in San Antonio, Texas. All eligible type 2 diabetic patients attending the clinics during 1994–1996 became part of the study. Data were obtained from the study database, medical records, hospital accounting, and pharmacy cost lists, and entered into a computerized database. Three groups were compared: a Community Clinic Nurse Case Manager (CC-TA) following treatment algorithms, a University Clinic Nurse Case Manager (UC-TA) following treatment algorithms, and Primary Care Physicians (PCP) following conventional care practices at a Family Practice Clinic. The algorithms provided a disease management model specifically for hyperglycemia, dyslipidemia, hypertension, and microalbuminuria that progressively moved the patient toward ideal goals through adjustments in medication, self-monitoring of blood glucose, meal planning, and reinforcement of diet and exercise. Cost effectiveness of hemoglobin AI, final endpoints was compared. ^ Results. There were 358 patients analyzed: 106 patients in CC-TA, 170 patients in UC-TA, and 82 patients in PCP groups. Change in hemoglobin A1c (HbA1c) was the primary outcome measured. HbA1c results were presented at baseline, 6 and 12 months for CC-TA (10.4%, 7.1%, 7.3%), UC-TA (10.5%, 7.1%, 7.2%), and PCP (10.0%, 8.5%, 8.7%). Mean patient compliance was 81%. Levels of cost effectiveness were significantly different between clinics. ^ Conclusion. Nurse case management with treatment algorithms significantly improved glycemic control in patients with type 2 diabetes, and was more cost effective. ^
Resumo:
This work is the result of a year-long study of the definitions of inland wetlands in which definitions from geology, hydrogeology, hydrology, pedology, biology, systems ecology, sociology, economics, political sciences, public health and law were considered. Of these, geology, hydrogeology, hydrology, biology, systems ecology and economics are discussed in detail in this report and used in writing a final theoretical (ideal) definition of inland wetlands for the glaciated northeastern United States. A proposed legal definition for Connecticut is also offered with descriptions and explanations of terms.
Resumo:
Infection with certain types of HPV is a necessary event in the development of cervical carcinoma; however, not all women who become infected will progress. While much is known about the molecular influence of HPV E6 and E7 proteins on the malignant transformation, little is known about the additional factors needed to drive the process. Currently, conventional cervical screening is insufficient at identifying women who are likely to progress from premalignant lesions to carcinoma. Aneuploidy and chromatin texture from image cytometry have been suggested as quantitative measures of nuclear damage in premalignant lesions and cancer, and traditional epidemiologic studies have identified potential factors to aid in the discrimination of those lesions likely to progress. ^ In the current study, real-time PCR was used to quantitate mRNA expression of the E7 gene in women exhibiting normal epithelium, LSIL, and HSIL. Quantitative cytometry was used to gather information about the DNA index and chromatin features of cells from the same women. Logistic regression modeling was used to establish predictor variables for histologic grade based on the traditional epidemiologic risk factors and molecular markers. ^ Prevalence of mRNA transcripts was lower among women with normal histology (27%) than for women with LSIL (40%) and HSIL (37%) with mean levels ranging from 2.0 to 4.2. The transcriptional activity of HPV 18 was higher than that of HPV 16 and increased with increasing level of dysplasia, reinforcing the more aggressive nature of HPV 18. DNA index and mRNA level increased with increasing histological grade. Chromatin score was not correlated with histology but was higher for HPV 18 samples and those with both HPV 18 and HPV 16. However, chromatin score and DNA index were not correlated with mRNA levels. The most predictive variables in the regression modeling were mRNA level, DNA index, parity, and age, and the ROC curves for LSIL and HSIL indicated excellent discrimination. ^ Real-time PCR of viral transcripts could provide a more efficient method to analyze the oncogenic potential within cells from cervical swabs. Epidemiological modeling of malignant progression in the cervix should include molecular markers, as well as the traditional epidemiological risk factors. ^
Resumo:
Trust is important in medical relationships and for the achievement of better health outcomes. Developments in managed care in the recent years are believed to affect the quality of healthcare services delivery and to undermine trust in the healthcare provider. Physician choice has been identified as a strong predictor of provider trust but has not been studied in detail. Consumer satisfaction with primary care provider (PCP) choice includes having or not having physician choice. This dissertation developed a conceptual framework that guided the study of consumer satisfaction with PCP choice as a predictor of provider trust, and conducted secondary data analyses examining the association between PCP choice and trust, by identifying factors related to PCP choice satisfaction, and their relative importance in predicting provider trust. The study specific aims were: (1) to determine variables related to the factors: consumer characteristics and health status, information and consumer decision-making, consumer trust in providers in general and trust in the insurer, health plan financing and plan characteristics, and provider characteristics that may relate to PCP choice satisfaction; (2) to determine if the factors in aim one are related to PCP choice satisfaction; and (3) to analyze the association between PCP choice satisfaction and provider trust, controlling for potential confounders. Analyses were based on secondary data from a random national telephone survey in 1999, of residential households in the United States which included respondents aged over 20 and who had at least two visits with a health professional in the past two years. Among 1,117 eligible households interviewed (response rate 51.4%), 564 randomly selected to respond to insurer related questions made up the study sample. Analyses using descriptive statistics, and linear and logistic regressions found continual effective care and interaction with the PCP beyond the medical setting most predictive of PCP choice satisfaction. Four PCP choice satisfaction factors were also predictive of provider trust. Findings highlighted the importance of the PCP's professional and interpersonal competencies for the development of sustainable provider trust. Future research on the access, utilization, cognition, and helpfulness of provider specific information will further our understanding of consumer choice and trust. ^
Resumo:
Obesity is a complex multifactorial disease and is a public health priority. Perilipin coats the surface of lipid droplets in adipocytes and is believed to stabilize these lipid bodies by protecting triglyceride from early lipolysis. This research project evaluated the association between genetic variation within the human perilipin (PLIN) gene and obesity-related quantitative traits and disease-related phenotypes in Non-Hispanic White (NHW) and African American (AA) participants from the Atherosclerosis Risk in Communities (ARIC) Study. ^ Multivariate linear regression, multivariate logistic regression, and Cox proportional hazards models evaluated the association between single gene variants (rs2304794, rs894160, rs8179071, and rs2304795) and multilocus variation (rs894160 and rs2304795) within the PLIN gene and both obesity-related quantitative traits (body weight, body mass index [BMI], waist girth, waist-to-hip ratio [WHR], estimated percent body fat, and plasma total triglycerides) and disease-related phenotypes (prevalent obesity, metabolic syndrome [MetS], prevalent coronary heart disease [CHD], and incident CHD). Single variant analyses were stratified by race and gender within race while multilocus analyses were stratified by race. ^ Single variant analyses revealed that rs2304794 and rs894160 were significantly related to plasma triglyceride levels in all NHWs and NHW women. Among AA women, variant rs8179071 was associated with triglyceride levels and rs2304794 was associated with risk-raising waist circumference (>0.8 in women). The multilocus effects of variants rs894160 and rs2304795 were significantly associated with body weight, waist girth, WHR, estimated percent body fat, class II obesity (BMI ≥ 35 kg/m2), class III obesity (BMI ≥ 35 kg/m2), and risk-raising WHR (>0.9 in men and >0.8 in women) in AAs. Variant rs2304795 was significantly related to prevalent MetS among AA males and prevalent CHD in NHW women; multilocus effects of the PLIN gene were associated with prevalent CHD among NHWs. Rs2304794 was associated with incident CHD in the absence of the MetS among AAs. These findings support the hypothesis that variation within the PLIN gene influences obesity-related traits and disease-related phenotypes. ^ Understanding these effects of the PLIN genotype on the development of obesity can potentially lead to tailored health promotion interventions that are more effective. ^
Resumo:
Back symptoms are a major global public health problem with the lifetime prevalence ranging between 50-80%. Research suggests that work-related factors contribute to the occurrence of back pain in various industries. Despite the hazardous nature, strenuous tasks, and awkward postures associated with farm work, little is known about back injury and symptoms in farmworker adults and children. Research in the United States is particularly limited. This is a concern given the large proportion of migrant farmworkers in the United States without adequate access to healthcare as well as a substantial number of youth working in agriculture. The present study describes back symptoms and identifies work-related factors associated with back pain in migrant farmworker families and farmworker high school students from Starr County, TX. Two separate datasets were used from two cohort studies "Injury and Illness Surveillance in Migrant Farmworkers (MANOS)" (study A: n=267 families) and "South Texas Adolescent Rural Research Study (STARRS)" (study B: n=345). Descriptive and inferential statistics including multivariable logistic regression were used to identify work-related factors associated with back pain in each study. In migrant farmworker families, the prevalence of chronic back pain during the last migration season ranged from 9.5% among youngest children to 33.3% among mothers. Chronic back pain was significantly associated with increasing age; fairly bad/very bad quality of sleep while migrating; fewer than eight hours of sleep at home in Starr County, TX; depressive symptoms while migrating; self-provided water for washing hands/drinking; weeding at work; and exposure to pesticide drift/direct spray. Among farmworker adolescents, the prevalence of severe back symptoms was 15.7%. Severe back symptoms were significantly associated with being female; history of a prior accident/back injury; feeling tense, stressed, or anxious sometimes/often; lifting/carrying heavy objects not at work; current tobacco use; increasing lifetime number of migrant farmworker years; working with/around knives; and working on corn crops. Overall, results support that associations between work-related exposures and chronic back pain and severe back symptoms remain after controlling for the effect of non-work exposures in farmworker populations. ^
Resumo:
Enteroaggregative Escherichia coli (EAEC) are considered an important emerging enteric and food-borne pathogen. The groups importantly affected by EAEC include international travelers, children in the developing world, and patients with HIV infection. EAEC does not commonly cause diarrheal illness in all hosts. ^ The reasons for the observed clinical variation in EAEC infection are multifactorial and are dependant on the pathogen, the inoculum ingested and the host susceptibility. A major obstacle in identifying the mechanism of pathogenesis for EAEC is the heterogeneity in virulence of strains. No EAEC virulence gene is consistently present in all diarrheagenic strains. However, a recent report suggests that a package of plasmid borne and chromosomal virulence factors are under the control of the described transcriptional activator aggR. Although the exact inoculum required for EAEC diarrheal illness is not known, a volunteer study has shown that oral ingestion of 10 10 cfu of virulent EAEC elicited diarrhea. Ongoing studies are being conducted to better define the exact infectious dose. There are also host factors associated with increased susceptibility of persons to diarrheal illness with EAEC. ^ The following three manuscripts: (1) review EAEC as an emerging enteric pathogen; (2) identify EAEC as a cause of acute diarrhea among different subpopulations worldwide; (3) identify virulence characteristics and the molecular epidemiology of EAEC isolates among travelers with diarrheal illness and describe the pathogenesis of EAEC infection. ^
Resumo:
The ordinal logistic regression models are used to analyze the dependant variable with multiple outcomes that can be ranked, but have been underutilized. In this study, we describe four logistic regression models for analyzing the ordinal response variable. ^ In this methodological study, the four regression models are proposed. The first model uses the multinomial logistic model. The second is adjacent-category logit model. The third is the proportional odds model and the fourth model is the continuation-ratio model. We illustrate and compare the fit of these models using data from the survey designed by the University of Texas, School of Public Health research project PCCaSO (Promoting Colon Cancer Screening in people 50 and Over), to study the patient’s confidence in the completion colorectal cancer screening (CRCS). ^ The purpose of this study is two fold: first, to provide a synthesized review of models for analyzing data with ordinal response, and second, to evaluate their usefulness in epidemiological research, with particular emphasis on model formulation, interpretation of model coefficients, and their implications. Four ordinal logistic models that are used in this study include (1) Multinomial logistic model, (2) Adjacent-category logistic model [9], (3) Continuation-ratio logistic model [10], (4) Proportional logistic model [11]. We recommend that the analyst performs (1) goodness-of-fit tests, (2) sensitivity analysis by fitting and comparing different models.^
Resumo:
The objective of this cross sectional pilot study was to understand the cultural and social influences associated with the participation and retention of Mexican American parents in research studies. Mexican American parent's participation is limited due to cultural barriers that researchers may not recognize. Successful recruitment and retention of participants is a critical element for prevention research, particularly for groups that are underrepresented and carry a high burden of disease (Dunika, Garza, Roosa, & Stoerzinger, 1997). ^ The goal of this pilot study was to increase the understanding of research participation, recruitment and retention strategies among Mexican American adults using an instrument based on the Health Belief Model. This instrument was used to assess the cultural beliefs of Mexican American adults toward research participation. The dependent variable (research scenarios indexed by invasiveness) for each participant was compared to the independent variable (HBM scores) using chi-square analysis to see how the Health Belief Model constructs of perceived threat, perceived barriers, cues to action and perceived benefits are associated with how willing the participants are to participate in different risk levels of research. Descriptive statistics were used to assess the items on the instrument regarding acculturation, demographics, and sample size. ^ This study expands on current knowledge of research participation and retention strategies and methods involving the Mexican American parents. Using data from this study, researchers can observe relevant patterns from the participant's responses.^
Resumo:
Anticancer drugs typically are administered in the clinic in the form of mixtures, sometimes called combinations. Only in rare cases, however, are mixtures approved as drugs. Rather, research on mixtures tends to occur after single drugs have been approved. The goal of this research project was to develop modeling approaches that would encourage rational preclinical mixture design. To this end, a series of models were developed. First, several QSAR classification models were constructed to predict the cytotoxicity, oral clearance, and acute systemic toxicity of drugs. The QSAR models were applied to a set of over 115,000 natural compounds in order to identify promising ones for testing in mixtures. Second, an improved method was developed to assess synergistic, antagonistic, and additive effects between drugs in a mixture. This method, dubbed the MixLow method, is similar to the Median-Effect method, the de facto standard for assessing drug interactions. The primary difference between the two is that the MixLow method uses a nonlinear mixed-effects model to estimate parameters of concentration-effect curves, rather than an ordinary least squares procedure. Parameter estimators produced by the MixLow method were more precise than those produced by the Median-Effect Method, and coverage of Loewe index confidence intervals was superior. Third, a model was developed to predict drug interactions based on scores obtained from virtual docking experiments. This represents a novel approach for modeling drug mixtures and was more useful for the data modeled here than competing approaches. The model was applied to cytotoxicity data for 45 mixtures, each composed of up to 10 selected drugs. One drug, doxorubicin, was a standard chemotherapy agent and the others were well-known natural compounds including curcumin, EGCG, quercetin, and rhein. Predictions of synergism/antagonism were made for all possible fixed-ratio mixtures, cytotoxicities of the 10 best-scoring mixtures were tested, and drug interactions were assessed. Predicted and observed responses were highly correlated (r2 = 0.83). Results suggested that some mixtures allowed up to an 11-fold reduction of doxorubicin concentrations without sacrificing efficacy. Taken together, the models developed in this project present a general approach to rational design of mixtures during preclinical drug development. ^
Resumo:
Purpose. No Child Left Behind aimed to "improve the academic achievement of the disadvantaged." The primary research question considered how academic achievement of those from economic disadvantage compared to those not from disadvantage? ^ Economically disadvantaged students can potentially have added academic disadvantage. Research shows low academic achievement can potentially result in drug abuse, youth violence, and teen pregnancy. ^ Methods. To compare the student populations, measures included TAKS results and academic indicator data collected by the Texas Education Agency. ^ Results. T-test analyses showed a significant difference between the economically and non-economically disadvantaged student populations in meeting the TAKS passing standard, graduation, and preparation for higher education.^ Conclusions. The achievement gap between students remained as indicated by the Texas testing program. More research and time are needed to observe if the desired impact on those from economic disadvantage will be reflected by academic achievement data.^