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Mark A Hall

Publications and source records attributed to Mark A Hall.

At least 19 recordsLinked to original sources
PubMed2006

Policies of academic medical centers for disclosing financial conflicts of interest to potential research participants.

PURPOSE: To document the current state of institutional review board (IRB) and conflict of interest committee policies regarding disclosures of financial conflicts of interest to potential research participants, and to use this information to identify and share models for effectively achieving disclosure. METHOD: The authors identified the 123 U.S. academic medical centers that have IRBs and sought their IRB and institutional policies regarding financial conflicts of interest. In February and March 2004, using manual and key word searches, each institution's Web site was searched to identify documents containing information regarding the disclosure of financial conflicts of interest. Letters were sent to 24 institutions that had either no information or incomplete information posted on their Web sites. To assess institutions' guidelines for disclosure, the authors extracted and content coded each institution's information on disclosure. RESULTS: Relevant information was obtained from 120 (98%) academic medical centers (AMCs), of which 57 (48%) mentioned disclosing financial conflicts to potential research participants. Of these 57, 33 (58%) included verbatim language that could be used in informed consent documents. AMCs' recommendations and requirements for disclosure included details of the financial arrangement, administrative management of conflicts of interest, and encouragement of dialogue between the investigator and the potential research participant. CONCLUSIONS: Considerable variability exists concerning the specific information that should be disclosed. Most of the AMCs' policies were consistent with the goal of protection from legal liability. Significant questions remain, however, concerning the goals of disclosure and the most effective methods for achieving those goals.

Academic Medical Centers↗
PubMed2006

The essential haematopoietic transcription factor Scl is also critical for neuronal development.

Abstract The basic helix-loop-helix (bHLH) transcription factor Scl displays tissue-restricted expression and is critical for the establishment of the haematopoietic system; loss of Scl results in embryonic death due to absolute anaemia. Scl is also expressed in neurons of the mouse diencephalon, mesencephalon and metencephalon; however, its requirement in those sites remains to be determined. Here we report conditional deletion of Scl in neuronal precursor cells using the Cre/LoxP system. Neuronal-Scl deleted mice died prematurely, were growth retarded and exhibited an altered motor phenotype characterized by hyperactivity and circling. Moreover, ablation of Scl in the nervous system affected brain morphology with abnormal neuronal development in brain regions known to express Scl under normal circumstances; there was an almost complete absence of Scl-null neurons in the hindbrain and partial loss of Scl-null neurons in the thalamus and midbrain from early neurogenesis onwards. Our results demonstrate a crucial role for Scl in the development of Scl-expressing neurons, including gamma-aminobutyric acid (GABA)ergic interneurons. Our study represents one of the first demonstrations of functional overlap of a single bHLH protein that regulates neural and haematopoietic cell development. This finding underlines Scl's critical function in cell fate determination of mesodermal as well as neuroectodermal tissues.

Acoustic Stimulation↗
PubMed2006

For-profit conversion of Blue Cross plans: public benefit or public harm?

Conversions of Blue Cross plans to for-profit status have the potential to remake the corporate landscape of health care finance. Absent regulatory intervention, current trends could easily result in more than half of Blue Cross subscribers being in for-profit plans, a phenomenon far more significant than the conversion of nonprofit hospitals. Therefore, regulators' deliberations over conversion proposals are beginning to focus on the health policy impacts. This chapter surveys the full range of health policy implications by analyzing all existing studies of Blue Cross conversions and reporting on the authors' own case studies of conversion impacts. These studies conclude that conversions have not caused major negative impacts on the availability or accessibility of health care in the states in which conversions have occurred so far. However, a great deal of uncertainty exists about the actual effects of previous conversions, and each state is unique; therefore, even if the historical record were clear, it is difficult to predict with great certainty what the actual effects will be in another state undergoing a Blue conversion.

Blue Cross Blue Shield Insurance Plans↗
PubMed2005

Development of abbreviated measures to assess patient trust in a physician, a health insurer, and the medical profession.

BACKGROUND: Despite the recent proliferation in research on patient trust, it is seldom a primary outcome, and is often a peripheral area of interest. The length of our original scales to measure trust may limit their use because of the practical needs to minimize both respondent burden and research cost. The objective of this study was to develop three abbreviated scales to measure trust in: (1) a physician, (2) a health insurer, and (3) the medical profession. METHODS: Data from two samples were used. The first was a telephone survey of English-speaking adults in the United States (N = 1117) and the second was a telephone survey of English-speaking adults residing in North Carolina who were members of a health maintenance organization (N = 1024). Data were analyzed to examine data completeness, scaling assumptions, internal consistency properties, and factor structure. RESULTS: Abbreviated measures (5-items) were developed for each of the three scales. Cronbach's alpha was 0.87 for trust in a physician (test-retest reliability = 0.71), 0.84 for trust in a health insurer (test-retest reliability = 0.73), and 0.77 for trust in the medical profession. CONCLUSION: Assessment of data completeness, scale score dispersion characteristics, reliability and validity test results all provide evidence for the soundness of the abbreviated 5-item scales.

Adult↗
PubMed2005

Gene selection from microarray data for cancer classification--a machine learning approach.

A DNA microarray can track the expression levels of thousands of genes simultaneously. Previous research has demonstrated that this technology can be useful in the classification of cancers. Cancer microarray data normally contains a small number of samples which have a large number of gene expression levels as features. To select relevant genes involved in different types of cancer remains a challenge. In order to extract useful gene information from cancer microarray data and reduce dimensionality, feature selection algorithms were systematically investigated in this study. Using a correlation-based feature selector combined with machine learning algorithms such as decision trees, naïve Bayes and support vector machines, we show that classification performance at least as good as published results can be obtained on acute leukemia and diffuse large B-cell lymphoma microarray data sets. We also demonstrate that a combined use of different classification and feature selection approaches makes it possible to select relevant genes with high confidence. This is also the first paper which discusses both computational and biological evidence for the involvement of zyxin in leukaemogenesis.

Algorithms↗
PubMed2005

Patient acceptability of genotypic testing for hemochromatosis in primary care.

PURPOSE: Genetic screening can enable timely detection and treatment of hereditary hemochromatosis (HH). Little is known about patient acceptability of DNA testing as compared to conventional phenotypic testing. METHODS: Within the HEIRS Study, a large primary-care screening study of HH and iron overload, we randomly assigned participants to receive brief information on either HH genotypic or phenotypic testing, and assessed the willingness to accept this test. The study was designed to recruit an equal number of African Americans and Caucasians. RESULTS: A total of 2500 participants were recruited from waiting rooms of primary care practices; 2165 participants who self-identified as African Americans and Caucasians were included in the analyses. Overall, 56% had accepted a genotypic test versus 58% for a phenotypic test. Adjusting for Field Center (FC), age, gender, race, educational attainment, global health rating, and knowledge of the test, the odds ratio of accepting a genotypic versus phenotypic test was 0.85 (95% CI: 0.71, 1.02; P = 0.078). Characteristics associated with test acceptance were age 45-64 years, female gender, Caucasian race, self-rated health less than ''very good'', and knowledge of the test. Test acceptance was associated with interest in knowing more about health (81%) and in helping family members (71%). Refusal reasons included a need to talk with a doctor (44%), concern about privacy (32%), and dislike of blood drawing (29%). CONCLUSION: In this diverse sample of primary care patients, stated acceptance of genotypic testing for HH mutations was similar to phenotypic testing for blood iron. Patient education regarding the nature of test, importance of disease detection, and privacy protection appear to be essential for achieving high rates of screening participation.

Adult↗
PubMed2005

Impacts of managed care patient protection laws on health services utilization and patient satisfaction with care.

OBJECTIVE: To assess effects of patient protection laws implemented by the vast majority of states during the 1990s on the public's satisfaction and trust relating to health care, and on key utilization measures. DATA SOURCES/STUDY SETTING: Measures of individuals' health care utilization and satisfaction, and control variables, came from three waves of the Community Tracking Study (CTS) Household Surveys conducted in 1996-1997, 1998-1999, and 2000-2001. The CTS was conducted in 60 randomly selected communities, throughout the U.S. In addition, a supplemental national sample of households from CTS was also included, resulting in a combined sample with cases from 48 states and the District of Columbia. After applying exclusion restrictions, the analysis sample was 149,688 adults. STUDY DESIGN: Using a fixed-effects methodology, we assessed the influence of patient protection laws on satisfaction with care and utilization of services for the entire sample and for subsamples of persons in poor health, with low income, and who were enrolled in HMOs. DATA COLLECTION/EXTRACTION METHODS: One of the authors (Hall) compiled relevant laws in all U.S. states through 2001 from primary legal sources, checking for accuracy by conducting independent research on statutory changes and by asking three to five regulators in each state to verify that the information was correct. PRINCIPAL FINDINGS: Overall, patient protection laws had little or no effect on either trust, satisfaction with care, or utilization. Significance was found postenactment of a state patient protection law only for emergency room visits in the general sample, and only for physician trust in the low-income sample. Because of the number of possible associations examined, occasional findings of significance could occur by chance. CONCLUSIONS: Enactment of managed care patient protection laws did not generally increase utilization of health services or improve patient satisfaction with care.

Adolescent↗
PubMed2005

Functional but abnormal adult erythropoiesis in the absence of the stem cell leukemia gene.

Previous studies have indicated that the stem cell leukemia gene (SCL) is essential for both embryonic and adult erythropoiesis. We have examined erythropoiesis in conditional SCL knockout mice for at least 6 months after loss of SCL function and report that SCL was important but not essential for the generation of mature red blood cells. Although SCL-deleted mice were mildly anemic with increased splenic erythropoiesis, they responded appropriately to endogenous erythropoietin and hemolytic stress, a measure of late erythroid progenitors. However, SCL was more important for the proliferation of early erythroid progenitors because the predominant defects in SCL-deleted erythropoiesis were loss of in vitro growth of the burst-forming erythroid unit and an in vivo growth defect revealed by transplant assays. With respect to erythroid maturation, SCL-deleted proerythroblasts could generate more mature erythroblasts and circulating red blood cells. However, SCL was required for normal expression of TER119, one of the few proposed target genes of SCL. The unexpected finding that SCL-independent erythropoiesis can proceed in the adult suggests that alternate factors can replace the essential functions of SCL and raises the possibility that similar mechanisms also explain the relatively minor defects previously observed in SCL-null hematopoietic stem cells.

Aging↗
PubMed2005

The death of managed care: a regulatory autopsy.

On the heels of widespread patient protection legislation in the states, the managed care industry abandoned or greatly scaled back the core elements of gate-keeping, utilization management, and financial incentives, which are the very targets of this legislation. This article explores whether, and to what extent, the industry's abrupt change in course can be attributed to these laws. Based on extensive interviews with key informants in six representative states, the article concludes that these laws were not the primary driver of changes in managed care practices. However, patient protection laws interacted with other social and market forces, through complex forms of feedback and reinforcement, to bring about more thoroughgoing change than would have otherwise occurred.

Gatekeeping↗
PubMed2005

Do employers voluntarily include patient protections in self-insured managed care plans?

Managed care patient protection laws passed by states do not apply to health plans sponsored by self-insured employers, although 54% of workers who receive health insurance coverage through their employer are in self-insured plans. In-depth interviews conducted in five states with employers offering self-insured health benefits and with other knowledgeable market informants provide evidence that self-insured managed care plans nonetheless include important features that strengthen subscribers' access to medical providers. Less common in these plans were features providing for independent external appeal of coverage denials and for protecting network providers from undue influence by plan administrators.

Employee Retirement Income Security Act↗
PubMed2005

How patients' trust relates to their involvement in medical care.

OBJECTIVES: To examine the connection between patients' trust and their attitudes toward seeking care, participating in medical decision making, and adhering to treatment recommendations. METHODS: Data were collected from a national telephone survey of English-speaking adults (N=553) in 1999. Eligibility requirements were some type of public or private health care coverage and having seen a physician or other health professional at least twice in the past 2 years. Five questions on preferred role in medical care were asked. Trust in physicians and satisfaction with care were separately measured using validated scales. RESULTS: The most significant predictor of patients' preferred role in medical care is trust in the medical profession. Views also varied by sex, age, health, education, income, number of visits/years with physician, past dispute with a physician, and satisfaction with care, but many of these bivariate associations were no longer significant in multivariate regression models. Views varied slightly by trust in the specific physician. There were no racial differences. CONCLUSIONS: A strong connection exists between patients' preferred involvement in medical care and trust in the medical profession, but only a slight connection with trust in their own physician. Increased trust in physicians generally is associated with greater willingness to seek care, to follow recommendations of physicians, and to grant them decisional authority. Higher trust in a specific physician is strongly associated only with greater reported adherence. Although higher trust in the medical profession appears to entail a more deferential role by patients, higher trust is also consistent with more active patient roles such as seeking care and adhering to treatment regimens.

Adult↗
PubMed2004

Managed care patient protection or provider protection? A qualitative assessment.

PURPOSE: Opponents of managed care regulation allege that a patient's bill of rights, in reality, represents provider protections motivated by the desire to curtail the economic onslaught of managed care. This claim is assessed through a large qualitative study of state managed care patient protection laws. METHODS: State laws were reviewed and categorized, and regulators in each state were surveyed, to determine the pattern and content of relevant enactments as of the end of 2001. In 2002, six states were selected for in-depth case studies to reflect a range of market, demographic, and legal characteristics. In each state, 16 to 24 key informants were interviewed, including provider advocates, physician practices, health plan managers, regulators, patient advocates, and various industry observers. Additional interviews were conducted from a national perspective, for a total of 138 interviews. Interviews were semistructured, and interview notes were analyzed using qualitative techniques. RESULTS: These laws are directed primarily to patients' rights and only secondarily to providers' interests. Enactment of these laws was rarely attributed primarily to provider advocacy. Instead, providers aligned with consumers, or the impetus came from legislators or regulators. There was little evidence that these laws, collectively or individually, have had much effect on providers' economic concerns. Health plans are still free to form and shape networks as they see fit, subject to competitive constraints. Provider due process laws might suppress deselection to some extent, but most subjects thought these laws only marginally restrain health insurers from removing providers who they no longer want. CONCLUSION: Managed care patient protection laws do not advance a self-interested provider agenda that disables features of managed care that are beneficial to consumers. Instead, these laws appear to embody a convenient alignment of interests among providers, patients, and lawmakers.

Government Regulation↗
PubMed2004

In vivo fate-tracing studies using the Scl stem cell enhancer: embryonic hematopoietic stem cells significantly contribute to adult hematopoiesis.

Evidence for the lineage relationship between embryonic and adult hematopoietic stem cells (HSCs) in the mouse is primarily indirect. In order to study this relationship in a direct manner, we expressed the tamoxifen-inducible Cre-ER(T) recombinase under the control of the stem cell leukemia (Scl) stem-cell enhancer in transgenic mice (HSC-SCL-Cre-ER(T)). To determine functionality, HSC-SCL-Cre-ER(T) transgenics were bred with Cre reporter mice. Flow cytometric and transplantation studies revealed tamoxifen-dependent recombination occurring in more than 90% of adult long-term HSCs, whereas the targeted proportion within mature progenitor populations was significantly lower. Moreover, the transgene was able to irreversibly tag embryonic HSCs on days 10 and 11 of gestation. These cells contributed to bone marrow hematopoiesis 5 months later. In order to investigate whether the de novo HSC generation is completed during embryogenesis, HSC-SCL-Cre-ER(T)-marked fetal liver cells were transplanted into adult recipients. Strikingly, the proportion of marked cells within the transplanted and the in vivo-remaining HSC compartment was not different, implying that no further HSC generation occurred during late fetal and neonatal stages of development. These data demonstrate for the first time the direct lineage relationship between midgestation embryonic and adult HSCs in the mouse. Additionally, the HSC-SCL-Cre-ER(T) mice will provide a valuable tool to achieve temporally controlled genetic manipulation of HSCs.

Age Factors↗
PubMed2004

How patient-physician encounters in critical medical situations affect trust: results of a national survey.

BACKGROUND: Patients' trust in physicians and in the medical profession is vital for a successful patient-physician relationship. Trust is especially salient in critical medical situations, such as serious side-effects, hospitalizations, and diagnoses of serious medical conditions, but most trust studies have been done with the general population or in routine primary care settings. This study examines the association between patient-physician encounters in such critical medical situations and patients' trust in their physician and in the medical profession in general. METHODS: A random national telephone survey was conducted using validated multi-item questionnaire measuring trust and satisfaction with physicians and with the medical profession. A seven item questionnaire measured the patient-physician encounters in critical medical situations. A total of 1117 subjects aged 20 years and older with health insurance were included for analyses. Spearman rank order correlations were used to determine the association of encounter variables with trust in physicians and the medical profession. RESULTS: Prescription of medications by primary care physicians that patients believed might have side effects was negatively correlated with trust in physician (rho = -0.12, p < 0.001, n = 1045) in multivariate analysis. A primary care physician evaluating the patient for a condition the patient believed was serious was positively correlated with trust in physician (rho= 0.08, p < 0.01). Being hospitalized was positively correlated with trust in the medical profession (rho = 0.12, p < 0.01, n = 475). CONCLUSION: Hospitalization, perceived seriousness of condition, and concerns about the risks of medications were found to be associated with patient trust in physicians or the medical profession. These findings highlight the salience of trust in serious physician-patient encounters and the role that patient vulnerability plays in determining patient trust.

Adult↗
PubMed2004

Balancing commercial and public interests.

Alarge number of randomized clinical trials with important health outcomes are completed each year. Those with favorable findings are typically reported and published rapidly, while the publication of those with unfavorable results is often delayed or given a positive "spin." This observation applies primarily to industry-sponsored trials. Our objectives are to discuss the responsibility of pharmaceutical firms to the public with respect to timely, complete, and unbiased information from all randomized clinical trials and to propose solutions for improvements. We believe that in addition to financial obligations to their shareholders, pharmaceutical companies have social responsibilities to the public and to health care providers. However, private markets do not reward or compel optimal disclosure of drug safety or inferiority information on a voluntary basis.A problem which has not previously been identified relates to non-comparability of drugs. A case report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) illustrates how public interests may be violated due to failure to inform about drug inferiority. The current system for dissemination of relevant medical information could be improved if all involved parties collaborated fully. However, full disclosure of trial results is unlikely when research results are unfavorable to the firm. We conclude that expanded government regulations will be required for a satisfactory solution to the problem.

Editorial↗