122 research outputs found
Factors Associated with Preoperative Magnetic Resonance Imaging Use among Medicare Beneficiaries with Nonmetastatic Breast Cancer
Preoperative breast magnetic resonance imaging (MRI) use among Medicare beneficiaries with breast cancer has substantially increased from 2005 to 2009. We sought to identify factors associated with preoperative breast MRI use among women diagnosed with ductal carcinoma in situ (DCIS) or stage I-III invasive breast cancer (IBC)
Breast MRI in the Diagnostic and Preoperative Workup Among Medicare Beneficiaries With Breast Cancer
We compared the frequency and sequence of breast imaging and biopsy use for the diagnostic and preoperative workup of breast cancer according to breast MRI use among older women
Change in Terrestrial Human Footprint Drives Continued Loss of Intact Ecosystems
Human pressure mapping is important for understanding humanity's role in shaping Earth's patterns and processes. We provide the latest maps of the terrestrial human footprint and provide an assessment of change in human pressure across Earth. Between 2000 and 2013, 1.9 million km2 of land relatively free of human disturbance became highly modified. Our results show that humanity's footprint is eroding Earth's last intact ecosystems and that greater efforts are urgently needed to retain them
Amplitude measurements of Faraday waves
A light reflection technique is used to measure quantitatively the surface
elevation of Faraday waves. The performed measurements cover a wide parameter
range of driving frequencies and sample viscosities. In the capillary wave
regime the bifurcation diagrams exhibit a frequency independent scaling
proportional to the wavelength. We also provide numerical simulations of the
full Navier-Stokes equations, which are in quantitative agreement up to
supercritical drive amplitudes of 20%. The validity of an existing perturbation
analysis is found to be limited to 2.5% overcriticaly.Comment: 7 figure
Validation of a Pediatric Diabetes Case Definition Using Administrative Health Data in Manitoba, Canada
Costs of diagnostic and preoperative workup with and without breast MRI in older women with a breast cancer diagnosis
Abstract Background Breast cancer in the U.S. - estimated at 232,670 incident cases in 2014 - has the highest aggregate economic burden of care relative to other female cancers. Yet, the amount of cost attributed to diagnostic/preoperative work up has not been characterized. We examined the costs of imaging and biopsy among women enrolled in Medicare who did and did not receive diagnostic/preoperative Magnetic Resonance Imaging (MRI). Methods Using Surveillance, Epidemiology and End Results (SEER)- Medicare data, we compared the per capita costs (PCC) based on amount paid, between diagnosis date and primary surgical treatment for a breast cancer diagnosis (2005β2009) with and without diagnostic/preoperative MRI. We compared the groups with and without MRI using multivariable models, adjusting for woman and tumor characteristics. Results Of the 53,653 women in the cohort, within the diagnostic/preoperative window, 20Β % (Nβ=β10,776) received diagnostic/preoperative MRI. Total unadjusted median costs were almost double for women with MRI vs. without (1,152). Adjusted costs were higher among women receiving MRI, with significant differences in total costs (928), and biopsies costs ($138). Conclusion Costs of diagnostic/preoperative workups among women with MRI are higher than those without. Using these cost estimates in comparative effectiveness models should be considered when assessing the benefits and harms of diagnostic/preoperative MRI
Accuracy and completeness of patient pathways β the benefits of national data linkage in Australia
Background - The technical challenges associated with national data linkage, and the extent of cross-border population movements, are explored as part of a pioneering research project. The project involved linking state-based hospital admission records and death registrations across Australia for a national study of hospital related deaths. Methods - The project linked over 44 million morbidity and mortality records from four Australian states between 1st July 1999 and 31st December 2009 using probabilistic methods. The accuracy of the linkage was measured through a comparison with jurisdictional keys sourced from individual states. The extent of cross-border population movement between these states was also assessed. Results - Data matching identified almost twelve million individuals across the four Australian states. The percentage of individuals from one state with records found in another ranged from 3-5 %. Using jurisdictional keys to measure linkage quality, results indicate a high matching efficiency (F measure 97 to 99 %), with linkage processing taking only a matter of days. Conclusions - The results demonstrate the feasibility and accuracy of undertaking cross jurisdictional linkage for national research. The benefits are substantial, particularly in relation to capturing the full complement of records in patient pathways as a result of cross-border population movements. The project identified a sizeable βmobileβ population with hospital records in more than one state. Research studies that focus on a single jurisdiction will under-enumerate the extent of hospital usage by individuals in the population. It is important that researchers understand and are aware of the impact of this missing hospital activity on their studies. The project highlights the need for an efficient and accurate data linkage system to support national research across Australia
Geographic Access to Breast Imaging for US Women
The breast imaging modalities of mammography, ultrasound, and magnetic resonance imaging (MRI) are widely used for screening, diagnosis, treatment, and surveillance of breast cancer. Geographic access to breast imaging modalities is not known at a national level overall or for population subgroups
Phospholipase C-Ξ΅ Regulates Epidermal Morphogenesis in Caenorhabditis elegans
Migration of cells within epithelial sheets is an important feature of embryogenesis and other biological processes. Previous work has demonstrated a role for inositol 1,4,5-trisphosphate (IP3)-mediated calcium signalling in the rearrangement of epidermal cells (also known as hypodermal cells) during embryonic morphogenesis in Caenorhabditis elegans. However the mechanism by which IP3 production is stimulated is unknown. IP3 is produced by the action of phospholipase C (PLC). We therefore surveyed the PLC family of C. elegans using RNAi and mutant strains, and found that depletion of PLC-1/PLC-Ξ΅ produced substantial embryonic lethality. We used the epithelial cell marker ajm-1::gfp to follow the behaviour of epidermal cells and found that 96% of the arrested embryos have morphogenetic defects. These defects include defective ventral enclosure and aberrant dorsal intercalation. Using time-lapse confocal microscopy we show that the migration of the ventral epidermal cells, especially of the leading cells, is slower and often fails in plc-1(tm753) embryos. As a consequence plc-1 loss of function results in ruptured embryos with a Gex phenotype (gut on exterior) and lumpy larvae. Thus PLC-1 is involved in the regulation of morphogenesis. Genetic studies using gain- and loss-of-function alleles of itr-1, the gene encoding the IP3 receptor in C. elegans, demonstrate that PLC-1 acts through ITR-1. Using RNAi and double mutants to deplete the other PLCs in a plc-1 background, we show that PLC-3/PLC-Ξ³ and EGL-8/PLC-Ξ² can compensate for reduced PLC-1 activity. Our work places PLC-Ξ΅ into a pathway controlling epidermal cell migration, thus establishing a novel role for PLC-Ξ΅
Osteoporosis-related fracture case definitions for population-based administrative data
<p>Abstract</p> <p>Background</p> <p>Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a) compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b) test for differences in incidence estimates from multiple administrative data case definitions.</p> <p>Methods</p> <p>Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos). Generalized linear models were used to test for differences in incidence estimates.</p> <p>Results</p> <p>For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions.</p> <p>Conclusions</p> <p>The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.</p
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