THE MULTIPLE LOCATION TIME WEIGHTED INDEX: USING PATIENT ACTIVITY SPACES TO CALCULATE PRIMARY CARE SERVICE AREAS

Geographic health planning analyses, such as service area calculations, are hampered by a lack of patient-specific geographic data. Using the limited patient address information in patient management systems, planners analyze patient origin based on home address. But activity space research done sparingly in public health and extensively in non-health related arenas uses multiple addresses per person when analyzing accessibility. Also, health care access research has shown that there are many non-geographic factors that influence choice of provider. Most planning methods, however, overlook non-geographic factors influencing choice of provider, and the limited data mean the analyses can only be related to home address. This research attempted to determine to what extent geography plays a part in patient choice of provider and to determine if activity space data can be used to calculate service areas for primary care providers. During Spring 2008, a convenience sample of 384 patients of a locally-funded Community Health Center in Houston, Texas, completed a survey that asked about what factors are important when he or she selects a health care provider. A subset of this group (336) also completed an activity space log that captured location and time data on the places where the patient regularly goes. Survey results indicate that for this patient population, geography plays a role in their choice of health care provider, but it is not the most important reason for choosing a provider. Other factors for choosing a health care provider such as the provider offering “free or low cost visits”, meeting “all of the patient’s health care needs”, and seeing “the patient quickly” were all ranked higher than geographic reasons. Analysis of the patient activity locations shows that activity spaces can be used to create service areas for a single primary care provider. Weighted activity-space-based service areas have the potential to include more patients in the service area since more than one location per patient is used. Further analysis of the logs shows that a reduced set of locations by time and type could be used for this methodology, facilitating ongoing data collection for activity-space-based planning efforts.

Use of an Online Photo Management and Sharing Application to Create a Searchable Digital Dental Radiograph Repository

Problem: Dental radiographs generally display one or more findings/diagnoses, and are linked to a unique set of patient demographics, medical history and other findings not represented by the image. However, this information is not associated with radiographs in any type of meta format, and images are not searchable based on any clinical criteria (1,2). The purpose of this pilot study is to create an online, searchable data repository of dental radiographs to be used for patient care, teaching and research. [See PDF for complete abstract]

The Dissociation of Location and Object Working Memory using fMRI and MEG

Visual working memory (VWM) involves maintaining and processing visual information, often for the purpose of making immediate decisions. Neuroimaging experiments of VWM provide evidence in support of a neural system mainly involving a fronto-parietal neuronal network, but the role of specific brain areas is less clear. A proposal that has recently generated considerable debate suggests that a dissociation of object and location VWM occurs within the prefrontal cortex, in dorsal and ventral regions, respectively. However, re-examination of the relevant literature presents a more robust distribution suggestive of a general caudal-rostral dissociation from occipital and parietal structures, caudally, to prefrontal regions, rostrally, corresponding to location and object memory, respectively. The purpose of the present study was to identify a dissociation of location and object VWM across two imaging methods (magnetoencephalography, MEG, and functional magnetic imaging, fMRI). These two techniques provide complimentary results due the high temporal resolution of MEG and the high spatial resolution of fMRI. The use of identical location and object change detection tasks was employed across techniques and reported for the first time. Moreover, this study is the first to use matched stimulus displays across location and object VWM conditions. The results from these two imaging methods provided convergent evidence of a location and object VWM dissociation favoring a general caudal-rostral rather than the more common prefrontal dorsal-ventral view. Moreover, neural activity across techniques was correlated with behavioral performance for the first time and provided convergent results. This novel approach of combining imaging tools to study memory resulted in robust evidence suggesting a novel interpretation of location and object memory. Accordingly, this study presents a novel context within which to explore the neural substrates of WM across imaging techniques and populations.

Characterization and subchromosomal location of a novel tumor suppressor gene on human chromosome 7

Alterations in oncogenes and tumor suppressor genes (TSGs) are considered to be critical steps in oncogenesis. Consistent deletions and loss of heterozygosity (LOH) of polymorphic markers in a determinate chromosomal fragment are known to be indicative of a closely mapping TSG. Deletion of the long arm of chromosome 7 (hchr 7) is a frequent trait in many kinds of human primary tumors. LOH was studied with an extensive set of markers on chromosome 7q in several types of human neoplasias (primary breast, prostate, colon, ovarian and head and neck carcinomas) to determine the location of a putative TSG. The extent of LOH varied depending the type of tumor studied but all the LOH curves we obtained had a peak at (C-A)$\sb{\rm n}$ microsatellite repeat D7S522 at 7q31.1 and showed a Gaussian distribution. The high incidence of LOH in all tumor types studied suggests that a TSG relevant to the development of epithelial cancers is present on the 7q31.1. To investigate whether the putative TSG is conserved in the syntenic mouse locus, we studied LOH of 30 markers along mouse chromosome 6 (mchr 6) in chemically induced squamous cell carcinomas (SCCs). Tumors were obtained from SENCAR and C57BL/6 x DBA/2 F1 females by a two-stage carcinogenesis protocol. The high incidence of LOH in the tumor types studied suggests that a TSG relevant to the development of epithelial cancers is present on mchr 6 A1. Since this segment is syntenic with the hchr 7q31, these data indicate that the putative TSG is conserved in both species. Functional evidence for the existence of a TSG in hchr 7 was obtained by microcell fusion transfer of a single hchr 7 into a murine SCC-derived cell line. Five out of seven hybrids had two to three-fold longer latency periods for in vivo tumorigenicity assays than parental cells. One of the unrepressed hybrids had a deletion in the introduced chromosome 7 involving q31.1-q31.3, confirming the LOH data. ^

The location of majority and minority populations with respect to commercial treatment, storage, and disposal facilities in Texas

There is a growing interest in the location of Treatment, Storage, and Disposal (TSDF) sites in relation to minority communities. A number of studies have been completed, and the results of these studies have been varied. Some of the studies have shown a strong positive correlation between the location of TSDF sites and minority populations, while a few have shown no significance in that relationship. The major difference between these studies has been in the areal unit used.^ This study compared the minority populations of Texas census tracts and ZIP codes containing a TSDF using the associated county as the comparison population. The hypothesis of this study was that there was no difference between using census tracts and ZIP codes to analyze the relationship of minority populations and TSDF's. The census data used was from 1990, and the initial list of TSDF sites was supplied by the Texas Natural Resource Conservation Commission. The TSDF site locations were checked using graphical information systems (GIS) programs, in order to increase the accuracy of the identity of exposed ZIP codes and census tracts. The minority populations of the exposed areal units were compared using proportional differences, crosstables, maps, and logistic regression. The dependent variable used was the exposure status of the areal units under study, including counties, census tracts, and ZIP codes. The independent variables used included minority group proportion and grouping of the proportions, educational status, household income, and home value.^ In all cases, education was significant or near significant at the.05 level. Education rather than minority proportion was therefore the most significant predictor of the exposure status of a census tract or ZIP code. ^

The multiple location time weighted index: Using patient activity spaces to calculate primary care service areas

Geographic health planning analyses, such as service area calculations, are hampered by a lack of patient-specific geographic data. Using the limited patient address information in patient management systems, planners analyze patient origin based on home address. But activity space research done sparingly in public health and extensively in non-health related arenas uses multiple addresses per person when analyzing accessibility. Also, health care access research has shown that there are many non-geographic factors that influence choice of provider. Most planning methods, however, overlook non-geographic factors influencing choice of provider, and the limited data mean the analyses can only be related to home address. This research attempted to determine to what extent geography plays a part in patient choice of provider and to determine if activity space data can be used to calculate service areas for primary care providers. ^ During Spring 2008, a convenience sample of 384 patients of a locally-funded Community Health Center in Houston, Texas, completed a survey that asked about what factors are important when he or she selects a health care provider. A subset of this group (336) also completed an activity space log that captured location and time data on the places where the patient regularly goes. ^ Survey results indicate that for this patient population, geography plays a role in their choice of health care provider, but it is not the most important reason for choosing a provider. Other factors for choosing a health care provider such as the provider offering "free or low cost visits", meeting "all of the patient's health care needs", and seeing "the patient quickly" were all ranked higher than geographic reasons. ^ Analysis of the patient activity locations shows that activity spaces can be used to create service areas for a single primary care provider. Weighted activity-space-based service areas have the potential to include more patients in the service area since more than one location per patient is used. Further analysis of the logs shows that a reduced set of locations by time and type could be used for this methodology, facilitating ongoing data collection for activity-space-based planning efforts. ^

Use of light intensity, temperature, and humidity to verify exposure location

Research studies on the association between exposures to air contaminants and disease frequently use worn dosimeters to measure the concentration of the contaminant of interest. But investigation of exposure determinants requires additional knowledge beyond concentration, i.e., knowledge about personal activity such as whether the exposure occurred in a building or outdoors. Current studies frequently depend upon manual activity logging to record location. This study's purpose was to evaluate the use of a worn data logger recording three environmental parameters—temperature, humidity, and light intensity—as well as time of day, to determine indoor or outdoor location, with an ultimate aim of eliminating the need to manually log location or at least providing a method to verify such logs. For this study, data collection was limited to a single geographical area (Houston, Texas metropolitan area) during a single season (winter) using a HOBO H8 four-channel data logger. Data for development of a Location Model were collected using the logger for deliberate sampling of programmed activities in outdoor, building, and vehicle locations at various times of day. The Model was developed by analyzing the distributions of environmental parameters by location and time to establish a prioritized set of cut points for assessing locations. The final Model consisted of four "processors" that varied these priorities and cut points. Data to evaluate the Model were collected by wearing the logger during "typical days" while maintaining a location log. The Model was tested by feeding the typical day data into each processor and generating assessed locations for each record. These assessed locations were then compared with true locations recorded in the manual log to determine accurate versus erroneous assessments. The utility of each processor was evaluated by calculating overall error rates across all times of day, and calculating individual error rates by time of day. Unfortunately, the error rates were large, such that there would be no benefit in using the Model. Another analysis in which assessed locations were classified as either indoor (including both building and vehicle) or outdoor yielded slightly lower error rates that still precluded any benefit of the Model's use.^

Factors associated with needle sharing among Black male injection drug users in Harris County, Texas

Background. Injection drug users (IDUs) are at increased risk for HIV transmission due to unique risk behaviors, such as sharing needles. In Houston, IDUs account for 18% of all HIV/AIDS cases among Black males. ^ Objectives. This analysis compared demographic, behavioral, and psychosocial characteristics of needle sharing and non-sharing IDUs in a population of Black males in Harris County, Texas. ^ Methods. Data used for this analysis were from the second IDU cycle of the National HIV Behavioral Surveillance System. This dataset included a sample of 288 Black male IDUs. Univariate and multivariate statistical analysis were performed to determine statistically significant associations of needle sharing in this population and to create a functional model to inform local HIV prevention programs. ^ Results. Half of the participants in this analysis shared needles in the past 12 months. Compared to non-sharers, sharers were more likely to be homeless (OR=3.70, p<0.01) or arrested in the past year (OR=2.31, p<0.01), inject cocaine (OR=2.07, p<0.01), report male-to-male sex in the past year (OR=6.97, p<0.01), and to exchange sex for money or drugs. Sharers were less likely than non-sharers to graduate high school (OR=0.36, p<0.01), earn $5,000 or more a year (OR=1.15, p=0.05), get needles from a medical source (OR=0.59, p=0.03), and ever test for HIV (OR=0.17, p<0.01). Sharers were more likely to report depressive symptoms (OR=3.49, p<0.01), lower scores on the family support scale (mean difference 0.41, p=0.01) and decision-making confidence scale (mean difference 0.38, p<0.01), and greater risk-taking (mean difference -0.49, p<0.01) than non-sharers. In a multivariable logistic regression, sharers were less likely to have graduated high school (OR=0.33, p<0.01) and have been tested for HIV (OR=0.12, p<0.01) and were more likely to have been arrested in the past year (OR=2.3, p<0.01), get needles from a street source (OR=3.87, p<0.01), report male-to-male sex (OR=7.01, p<0.01), and have depressive symptoms (OR=2.36, p=0.02) and increased risk-taking (OR=1.78, p=0.01). ^ Conclusions. IDUs that shared needles are different from those that did not, reporting lower socioeconomic status, increased sexual and risk behaviors, increased depressive symptoms and increased risk-taking. These findings suggest that intervention programs that also address these demographic, behavioral, and psychosocial factors may be more successful in decreasing needle sharing among this population.^

THE EFFECTS OF COST-SHARING ON USE OF SERVICES AND CONSUMER CHARACTERISTICS IN A STATE'S CRIPPLED CHILDREN'S DIVISION

The present study analyzed some of the effects of imposing a cost-sharing requirement on users of a state's health service program. The study population consisted of people who were in diagnosed medical need and included, but was not limited to, people in financial need.^ The purpose of the study was to determine if the cost-sharing requirement had any detrimental effects on the service population. Changes in the characteristics of service consumers and in utilization patterns were analyzed using time-series techniques and pre-post policy comparisons.^ The study hypotheses stated that the distribution of service provided, diagnoses serviced, and consumer income levels would change following the cost-sharing policy.^ Analysis of data revealed that neither the characteristics of service users (income, race, sex, etc.) nor services provided by the program changed significantly following the policy. The results were explainable in part by the fact that all of the program participants were in diagnosed medical need. Therefore, their use of "discretionary" or "less necessary" services was limited.^ The study's findings supported the work of Joseph Newhouse, Charles Phelps, and others who have contended that necessary service use would not be detrimentally affected by reasonable cost-sharing provisions. These contentions raise the prospect of incorporating cost-sharing into programs such as Medicaid, which, at this writing, do not demand any consumer payment for services.^ The study concluded with a discussion of the cost-containment problem in health services. The efficacy of cost-sharing was considered relative to other financing and reimbursement strategies such as HMO's, self-funding, and reimbursement for less costly services and places of service. ^

A practice-based culminating experience: Writing a HRSA grant application with Texas Organ Sharing Alliance for public education efforts to increase solid organ donation

In November 2010, nearly 110,000 people in the United States were waiting for organs for transplantation. Despite the fact that the organ donor registration rate has doubled in the last year, Texas has the lowest registration rate in the nation. Due to the need for improved registration rates in Texas, this practice-based culminating experience was to write an application for federal funding for the central Texas organ procurement organization, Texas Organ Sharing Alliance. The culminating experience has two levels of significance for public health – (1) to engage in an activity to promote organ donation registration, and (2) to provide professional experience in grant writing. ^ The process began with a literature review. The review was to identify successful intervention activities in motivating organ donation registration that could be used in intervention design for the grant application. Conclusions derived from the literature review included (1) the need to specifically encourage family discussions, (2) religious and community leaders can be leveraged to facilitate organ donation conversations in families, (3) communication content must be culturally sensitive and (4) ethnic disparities in transplantation must be acknowledged and discussed.^ Post the literature review; the experience followed a five step process of developing the grant application. The steps included securing permission to proceed, assembling a project team, creation of a project plan and timeline, writing each element of the grant application including the design of proposed intervention activities, and completion of the federal grant application. ^ After the grant application was written, an evaluation of the grant writing process was conducted. Opportunities for improvement were identified. The first opportunity was the need for better timeline management to allow for review of the application by an independent party, iterative development of the budget proposal, and development of collaborative partnerships. Another improvement opportunity was the management of conflict regarding the design of the intervention that stemmed from marketing versus evidence-based approaches. The most important improvement opportunity was the need to develop a more exhaustive evaluation plan.^ Eight supplementary files are attached to appendices: Feasibility Discussion in Appendix 1, Grant Guidance and Workshop Notes in Appendix 2, Presentation to Texas Organ Sharing Alliance in Appendix 3, Team Recruitment Presentation in Appendix 5, Grant Project Narrative in Appendix 7, Federal Application Form in Appendix 8, and Budget Workbook with Budget Narrative in Appendix 9.^