Estimates of hospital and physician costs of epilepsy in the United States for 1995 comparing the provider -based survey method and a patient -based medical charts and billing method

This investigation compares two different methodologies for calculating the national cost of epilepsy: provider-based survey method (PBSM) and the patient-based medical charts and billing method (PBMC&BM). The PBSM uses the National Hospital Discharge Survey (NHDS), the National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Ambulatory Medical Care Survey (NAMCS) as the sources of utilization. The PBMC&BM uses patient data, charts and billings, to determine utilization rates for specific components of hospital, physician and drug prescriptions. ^ The 1995 hospital and physician cost of epilepsy is estimated to be $722 million using the PBSM and $1,058 million using the PBMC&BM. The difference of $336 million results from $136 million difference in utilization and $200 million difference in unit cost. ^ Utilization. The utilization difference of $136 million is composed of an inpatient variation of $129 million, $100 million hospital and $29 million physician, and an ambulatory variation of $7 million. The $100 million hospital variance is attributed to inclusion of febrile seizures in the PBSM, $−79 million, and the exclusion of admissions attributed to epilepsy, $179 million. The former suggests that the diagnostic codes used in the NHDS may not properly match the current definition of epilepsy as used in the PBMC&BM. The latter suggests NHDS errors in the attribution of an admission to the principal diagnosis. ^ The $29 million variance in inpatient physician utilization is the result of different per-day-of-care physician visit rates, 1.3 for the PBMC&BM versus 1.0 for the PBSM. The absence of visit frequency measures in the NHDS affects the internal validity of the PBSM estimate and requires the investigator to make conservative assumptions. ^ The remaining ambulatory resource utilization variance is $7 million. Of this amount, $22 million is the result of an underestimate of ancillaries in the NHAMCS and NAMCS extrapolations using the patient visit weight. ^ Unit cost. The resource cost variation is $200 million, inpatient is $22 million and ambulatory is $178 million. The inpatient variation of $22 million is composed of $19 million in hospital per day rates, due to a higher cost per day in the PBMC&BM, and $3 million in physician visit rates, due to a higher cost per visit in the PBMC&BM. ^ The ambulatory cost variance is $178 million, composed of higher per-physician-visit costs of $97 million and higher per-ancillary costs of $81 million. Both are attributed to the PBMC&BM's precise identification of resource utilization that permits accurate valuation. ^ Conclusion. Both methods have specific limitations. The PBSM strengths are its sample designs that lead to nationally representative estimates and permit statistical point and confidence interval estimation for the nation for certain variables under investigation. However, the findings of this investigation suggest the internal validity of the estimates derived is questionable and important additional information required to precisely estimate the cost of an illness is absent. ^ The PBMC&BM is a superior method in identifying resources utilized in the physician encounter with the patient permitting more accurate valuation. However, the PBMC&BM does not have the statistical reliability of the PBSM; it relies on synthesized national prevalence estimates to extrapolate a national cost estimate. While precision is important, the ability to generalize to the nation may be limited due to the small number of patients that are followed. ^

Camp For All Connection: a community health information outreach project

Purpose: The purpose of the Camp For All Connection project is to facilitate access to electronic health information resources at the Camp For All facility. Setting/Participants/Resources: Camp For All is a barrier-free camp working in partnership with organizations to enrich the lives of children and adults with chronic illnesses and disabilities and their families by providing camping and retreat experiences. The camp facility is located on 206 acres in Burton, Texas. The project partners are Texas Woman's University, Houston Academy of Medicine-Texas Medical Center Library, and Camp For All. Brief Description: The Camp For All Connection project placed Internet-connected workstations at the camp's health center in the main lodge and provided training in the use of electronic health information resources. A train-the-trainer approach was used to provide training to Camp For All staff. Results/Outcome: Project workstations are being used by health care providers and camp staff for communication purposes and to make better informed health care decisions for Camp For All campers. Evaluation Method: A post-training evaluation was administered at the end of the train-the-trainer session. In addition, a series of site visits and interviews was conducted with camp staff members involved in the project. The site visits and interviews allowed for ongoing dialog between project staff and project participants.

Prevalence of HIV risk-related behaviors among undocumented Central American immigrant women in Houston, Texas, 2010

The primary aim of this dissertation research is to provide epidemiological data on HIV risk-related behaviors among undocumented Central American immigrant women living in Houston, Texas. Between February and May 2010, we used respondent driven sampling (RDS) to recruit 230 Guatemalan, Honduran, and El Salvadoran women, ages 18 to 50 years, living in Houston without a valid United States visa or residency papers. RDS is a probability-based sampling method that utilizes social networks to access members of hidden populations that lack a sampling frame. Participants completed an interview regarding their demographics, access to and utilization of healthcare services, HIV testing, and sexual behaviors. Data from this study were used 1) to describe the prevalence of sexual HIV risk-related behaviors among undocumented Central American immigrant women, comparing those who recently immigrated to the U.S. (within the past five years) to those with more established residency (of over five years); 2) to describe the prevalence of lifetime HIV testing and evaluate its associated factors in this target population; and 3) to describe the effectiveness of RDS to access members of this target population. ^ As described in Paper 1, there was a generally low prevalence of individual HIV risk-related behaviors (i.e., multiple, concurrent, convenience, and casual sexual partnerships) among the undocumented Central American immigrant women in this study. However, there was evidence of HIV risk due to unprotected sex with male partners who have concurrent sexual partnerships. We identified recent immigrants as the subpopulation at greatest risk, as they were significantly more likely than established immigrants to have multiple and/or concurrent sexual partners. As described in Paper 2, the lifetime prevalence of HIV testing was almost 70%. After adjusting for age, number of years living in the U.S., income security, and resource barriers, lifetime HIV testing was significantly associated with being from Honduras, having more than a sixth grade education, having a regular healthcare provider, and having knowledge of available healthcare resources. Finally, as described in Paper 3, RDS was an effective method for obtaining a diverse sample of Central American immigrant women in Houston. ^ This project is the first to use RDS to conduct an HIV behavioral survey among undocumented Central American immigrant women. Our results will inform the design of future research studies and the implementation of HIV prevention activities among undocumented Central American immigrants in the U.S.^

DEVELOPMENT OF A BEAM-SPECIFIC PLANNING TARGET VOLUME AND A ROBUST PLAN ANALYSIS TOOL FOR PROTON THERAPY

Proton therapy is growing increasingly popular due to its superior dose characteristics compared to conventional photon therapy. Protons travel a finite range in the patient body and stop, thereby delivering no dose beyond their range. However, because the range of a proton beam is heavily dependent on the tissue density along its beam path, uncertainties in patient setup position and inherent range calculation can degrade thedose distribution significantly. Despite these challenges that are unique to proton therapy, current management of the uncertainties during treatment planning of proton therapy has been similar to that of conventional photon therapy. The goal of this dissertation research was to develop a treatment planning method and a planevaluation method that address proton-specific issues regarding setup and range uncertainties. Treatment plan designing method adapted to proton therapy: Currently, for proton therapy using a scanning beam delivery system, setup uncertainties are largely accounted for by geometrically expanding a clinical target volume (CTV) to a planning target volume (PTV). However, a PTV alone cannot adequately account for range uncertainties coupled to misaligned patient anatomy in the beam path since it does not account for the change in tissue density. In order to remedy this problem, we proposed a beam-specific PTV (bsPTV) that accounts for the change in tissue density along the beam path due to the uncertainties. Our proposed method was successfully implemented, and its superiority over the conventional PTV was shown through a controlled experiment.. Furthermore, we have shown that the bsPTV concept can be incorporated into beam angle optimization for better target coverage and normal tissue sparing for a selected lung cancer patient. Treatment plan evaluation method adapted to proton therapy: The dose-volume histogram of the clinical target volume (CTV) or any other volumes of interest at the time of planning does not represent the most probable dosimetric outcome of a given plan as it does not include the uncertainties mentioned earlier. Currently, the PTV is used as a surrogate of the CTV’s worst case scenario for target dose estimation. However, because proton dose distributions are subject to change under these uncertainties, the validity of the PTV analysis method is questionable. In order to remedy this problem, we proposed the use of statistical parameters to quantify uncertainties on both the dose-volume histogram and dose distribution directly. The robust plan analysis tool was successfully implemented to compute both the expectation value and its standard deviation of dosimetric parameters of a treatment plan under the uncertainties. For 15 lung cancer patients, the proposed method was used to quantify the dosimetric difference between the nominal situation and its expected value under the uncertainties.

Evaluation of a solid phase microextraction method for community-based monitoring of 1,3-butadiene and benzene in Houston, Texas

The Houston region is home to arguably the largest petrochemical and refining complex anywhere. The effluent of this complex includes many potentially hazardous compounds. Study of some of these compounds has led to recognition that a number of known and probable carcinogens are at elevated levels in ambient air. Two of these, benzene and 1,3-butadiene, have been found in concentrations which may pose health risk for residents of Houston.^ Recent popular journalism and publications by local research institutions has increased the interest of the public in Houston's air quality. Much of the literature has been critical of local regulatory agencies' oversight of industrial pollution. A number of citizens in the region have begun to volunteer with air quality advocacy groups in the testing of community air. Inexpensive methods exist for monitoring of ozone, particulate matter and airborne toxic ambient concentrations. This study is an evaluation of a technique that has been successfully applied to airborne toxics.^ This technique, solid phase microextraction (SPME), has been used to measure airborne volatile organic hydrocarbons at community-level concentrations. It is has yielded accurate and rapid concentration estimates at a relatively low cost per sample. Examples of its application to measurement of airborne benzene exist in the literature. None have been found for airborne 1,3-butadiene. These compounds were selected for an evaluation of SPME as a community-deployed technique, to replicate previous application to benzene, to expand application to 1,3-butadiene and due to the salience of these compounds in this community. ^ This study demonstrates that SPME is a useful technique for quantification of 1,3-butadiene at concentrations observed in Houston. Laboratory background levels precluded recommendation of the technique for benzene. One type of SPME fiber, 85 μm Carboxen/PDMS, was found to be a sensitive sampling device for 1,3-butadiene under temperature and humidity conditions common in Houston. This study indicates that these variables affect instrument response. This suggests the necessity of calibration within specific conditions of these variables. While deployment of this technique was less expensive than other methods of quantification of 1,3-butadiene, the complexity of calibration may exclude an SPME method from broad deployment by community groups.^

Use of empowerment evaluation to determine a sustainability plan for a community-based preconception care program

Women With IMPACT (WWI) is a community-based preconception care educational intervention. WWI is being implemented by the Impacting Maternal and Prenatal Care Together (IMPACT) Collaborative and targets zip codes in Harris County, Texas at high risk for infant mortality, low birthweight, and preterm birth. WWI started March 2012 and continues through August 2013. Three workshop series are planned. This study was conducted with participants and facilitators from the first workshop series. This study aimed to 1) evaluate the WWI program using empowerment evaluation, 2) engage all WWI stakeholders in an empowerment evaluation so the method could be adopted as a participatory evaluation process for future IMPACT activities, and 3) develop recommendations for sustainability of the WWI intervention, based on empowerment evaluation findings and results from the pre/post program evaluation completed by WWI participants. Study participants included WWI participants and facilitators and IMPACT Collaborative Steering Committee members. WWI participants were female, 18-35 year-old, non-pregnant residents of zip codes at high risk of adverse birth outcomes. All other study participants were 18 years or older. A two-phased empowerment evaluation (EE) was utilized in this study. Sessions 1-4 were conducted independently of one another – 3 with participants at different sites and one with the facilitators. The fifth session included WWI participant and facilitator representatives, and IMPACT Steering Committee members. Session 5 built upon the work of the other sessions. Observation notes were recorded during each session. Thematic content analysis was conducted on all EE tables and observation notes. Mission statements drafted by each group focused on improvement of physical and mental health through behavior change and empowerment of all participants. The top 5 overall program components were: physical activity, nutrition, self-worth, in-class communication, and stress. Goals for program improvement were set by EE participants for each of these components. Through thematic content analysis of the tables and observation notes, social support emerged as an important theme of the program among all participant groups. Change to a healthy lifestyle emerged as an important theme in terms of program improvement. Two-phased EE provided an opportunity for all program stakeholders to provide feedback regarding important program components and provide suggestions for program improvement. EE, thematic content analysis, pre/post evaluation results, and inherent program knowledge were triangulated to make recommendations to sustain the program once the initial funding ends. ^