23 research outputs found

    Discovery And Replication Of Cerebral Blood Flow Differences In Major Depressive Disorder

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    Major depressive disorder (MDD) is a serious, heterogeneous disorder accompanied by brain-related changes, many of which are still to be discovered or refined. Arterial spin labeling (ASL) is a neuroimaging technique used to measure cerebral blood flow (CBF; perfusion) to understand brain function and detect differences among groups. CBF differences have been detected in MDD, and may reveal biosignatures of disease-state. The current work aimed to discover and replicate differences in CBF between MDD participants and healthy controls (HC) as part of the EMBARC study. Participants underwent neuroimaging at baseline, prior to starting study medication, to investigate biosignatures in MDD. Relative CBF (rCBF) was calculated and compared between 106 MDD and 36 HC EMBARC participants (whole-brain Discovery); and 58 MDD EMBARC participants and 58 HC from the DLBS study (region-of-interest Replication). Both analyses revealed reduced rCBF in the right parahippocampus, thalamus, fusiform and middle temporal gyri, as well as the left and right insula, for those with MDD relative to HC. Both samples also revealed increased rCBF in MDD relative to HC in both the left and right inferior parietal lobule, including the supramarginal and angular gyri. Cingulate and prefrontal regions did not fully replicate. Lastly, significant associations were detected between rCBF in replicated regions and clinical measures of MDD chronicity. These results (1) provide reliable evidence for ASL in detecting differences in perfusion for multiple brain regions thought to be important in MDD, and (2) highlight the potential role of using perfusion as a biosignature of MDD

    An annotated bibliography of selected references on the estimated rates of direct ground-water discharge to the Great Lakes /

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    Shipping list no.: 99-0198-P."Prepared in cooperation with the U.S. Army Corps of Engineers, Detroit District."Includes bibliographical references (p. 20-24).Mode of access: Internet

    Cost inefficiency and mortality rates in Florida hospitals

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    This study examines the relationship between health outcomes and cost inefficiency in Florida hospitals over the period 1999-2001, with health outcomes measured by risk-adjusted in-hospital mortality rates. Previous research has come to conflicting conclusions regarding the relationship between costs and health outcomes. We hypothesize that these seemingly conflicting findings are due to the fact that total cost has two components - cost that reflects the best use of resources under current circumstances and cost associated with waste or inefficiency. By isolating costs due to inefficiency, we can examine directly their relationship, if any, to hospital mortality rates, and begin to assess whether policies that create incentives for hospitals to increase efficiency have adverse effects on health outcomes. We regress an in-hospital mortality index for each hospital on a measure of the hospital's cost inefficiency, obtained from a stochastic cost frontier estimation, as well as on predicted mortality and a set of variables linked to mortality performance. Our results indicate a positive and significant relationship between a hospital's mortality performance and its inefficiency: on average, a one percentage point reduction in cost inefficiency would be associated with one fewer in-hospital death per 10 000 discharges, holding patient risk and other factors constant. Copyright © 2005 John Wiley & Sons, Ltd.

    Statistical Analysis Plan For Stage 1 Embarc (establishing Moderators And Biosignatures Of Antidepressant Response For Clinical Care) Study

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    Antidepressant medications are commonly used to treat depression, but only about 30% of patients reach remission with any single first-step antidepressant. If the first-step treatment fails, response and remission rates at subsequent steps are even more limited. The literature on biomarkers for treatment response is largely based on secondary analyses of studies designed to answer primary questions of efficacy, rather than on a planned systematic evaluation of biomarkers for treatment decision. The lack of evidence-based knowledge to guide treatment decisions for patients with depression has lead to the recognition that specially designed studies with the primary objective being to discover biosignatures for optimizing treatment decisions are necessary. Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC) is one such discovery study. Stage 1 of EMBARC is a randomized placebo controlled clinical trial of 8 week duration. A wide array of patient characteristics is collected at baseline, including assessments of brain structure, function and connectivity along with electrophysiological, biological, behavioral and clinical features. This paper reports on the data analytic strategy for discovering biosignatures for treatment response based on Stage 1 of EMBARC
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