174 research outputs found
Identifying data set specific duplicate patient records
posterProbabilistic models are commonly used in the identification of duplicate records. These methods are usually more accurate than deterministic methods, but are exponentially more computationally complex. Thus to make them computationally feasible, they rely on deterministic blocking strategies. This project investigates how machine learning methods can be used to automatically determine an optimal blocking strategy using duplicate records already identified
Creation of an open source master person index from proprietary code: the open source "care data exchange" project
posterFrom 1998 to 2004 the ""Care Data Exchange"" (CDE) software was developed as a proprietary product by CareScience for the California HealthCare Foundation (CHCF). In 2005 CHCF asked Forrester Research to study the feasibility of releasing the CDE software assets under a free, open source license. The Forrester report articulated relationships between proprietary and nonproprietary components in the CDE Information Architecture (CIA)
Understanding the profile of errors that cause duplicate entries in a patient registry
posterDuplicate records are detrimental to the cost-effective and efficient delivery of health care. Manually identifying and resolving duplicates can cost $60 per case. Patterns have been found in the types of errors that occur in patient registries, suggesting that undetected duplicate records may be similar to those already identified. At the University of Utah, records from all community clinics are merged with hospital records in the Enterprise Data Warehouse (EDW). The Pedigree and Population Resource group at Huntsman Cancer Institute links demographic records from the EDW to the Utah Population Database (UPDB). In last year's linkage, 76,922 duplicate records were identified. The purpose of this study was to compare the differences between clinic and hospital records in the EDW with existing literature
Preserving academic poster content
posterPosters are an important way to share information between academia and industry. They are presented at national conferences, regional meetings, and even in university departments. There were almost 75,000 calls for poster submissions last year alone. Most posters are presented for only a few hours at a conference and may be difficult to translate into full papers. Posters are represented by abstracts submitted months before conferences. They may not accurately reflect poster content. A new method for preserving academic poster content is needed
Phylogenetically Widespread Multiple Paternity in New World Natricine Snakes
We used microsatellite DNA markers to identify the extent to which multiple paternity within litters occurs
among species of New World natricine snakes. We selected seven species to represent the three major clades of
Natricinae and all three subclades of the gartersnake clade. Microsatellite DNA genotyping of dams and litters confirmed
multiple paternity within litters of six species, including Thamnophis radix, T. sauritus, Storeria dekayi, S.
occipitomaculata, Nerodia rhombifer, and Regina septemvittata. Multiple paternity was not evident in one litter of nine
Thamnophis melanogaster. Together with published data documenting multiple paternity in T. bulteri, T. elegans, T.
sirtalis, and N. sipedon, these results confirm the phylogenetically widespread occurrence of multiple paternity among
New World natricines, emphasizing the need to consider phylogenetic (historical) explanations when analyzing snake
mating systems
Bayesian peak-bagging of solar-like oscillators using MCMC: A comprehensive guide
Context: Asteroseismology has entered a new era with the advent of the NASA
Kepler mission. Long and continuous photometric observations of unprecedented
quality are now available which have stimulated the development of a number of
suites of innovative analysis tools.
Aims: The power spectra of solar-like oscillations are an inexhaustible
source of information on stellar structure and evolution. Robust methods are
hence needed in order to infer both individual oscillation mode parameters and
parameters describing non-resonant features, thus making a seismic
interpretation possible.
Methods: We present a comprehensive guide to the implementation of a Bayesian
peak-bagging tool that employs a Markov chain Monte Carlo (MCMC). Besides
making it possible to incorporate relevant prior information through Bayes'
theorem, this tool also allows one to obtain the marginal probability density
function for each of the fitted parameters. We apply this tool to a couple of
recent asteroseismic data sets, namely, to CoRoT observations of HD 49933 and
to ground-based observations made during a campaign devoted to Procyon.
Results: The developed method performs remarkably well at constraining not
only in the traditional case of extracting oscillation frequencies, but also
when pushing the limit where traditional methods have difficulties. Moreover it
provides an rigorous way of comparing competing models, such as the ridge
identifications, against the asteroseismic data.Comment: Accepted for publication in A&
Structure and Rotation of the Solar Interior: Initial Results from the MDI Medium-L Program
The medium-l program of the Michelson Doppler Imager instrument on board SOHO provides continuous observations of oscillation modes of angular degree, l, from 0 to approximately 300. The data for the program are partly processed on board because only about 3% of MDI observations can be transmitted continuously to the ground. The on-board data processing, the main component of which is Gaussian-weighted binning, has been optimized to reduce the negative influence of spatial aliasing of the high-degree oscillation modes. The data processing is completed in a data analysis pipeline at the SOI Stanford Support Center to determine the mean multiplet frequencies and splitting coefficients. The initial results show that the noise in the medium-l oscillation power spectrum is substantially lower than in ground-based measurements. This enables us to detect lower amplitude modes and, thus, to extend the range of measured mode frequencies. This is important for inferring the Sun's internal structure and rotation. The MDI observations also reveal the asymmetry of oscillation spectral lines. The line asymmetries agree with the theory of mode excitation by acoustic sources localized in the upper convective boundary layer. The sound-speed profile inferred from the mean frequencies gives evidence for a sharp variation at the edge of the energy-generating core. The results also confirm the previous finding by the GONG (Gough et al., 1996) that, in a thin layer just beneath the convection zone, helium appears to be less abundant than predicted by theory. Inverting the multiplet frequency splittings from MDI, we detect significant rotational shear in this thin layer. This layer is likely to be the place where the solar dynamo operates. In order to understand how the Sun works, it is extremely important to observe the evolution of this transition layer throughout the 11-year activity cycle
COVID-19 TestNorm: A tool to normalize COVID-19 testing names to LOINC codes.
Large observational data networks that leverage routine clinical practice data in electronic health records (EHRs) are critical resources for research on coronavirus disease 2019 (COVID-19). Data normalization is a key challenge for the secondary use of EHRs for COVID-19 research across institutions. In this study, we addressed the challenge of automating the normalization of COVID-19 diagnostic tests, which are critical data elements, but for which controlled terminology terms were published after clinical implementation. We developed a simple but effective rule-based tool called COVID-19 TestNorm to automatically normalize local COVID-19 testing names to standard LOINC (Logical Observation Identifiers Names and Codes) codes. COVID-19 TestNorm was developed and evaluated using 568 test names collected from 8 healthcare systems. Our results show that it could achieve an accuracy of 97.4% on an independent test set. COVID-19 TestNorm is available as an open-source package for developers and as an online Web application for end users (https://clamp.uth.edu/covid/loinc.php). We believe that it will be a useful tool to support secondary use of EHRs for research on COVID-19
Similar Risk of Kidney Failure among Patients with Blinding Diseases Who Receive Ranibizumab, Aflibercept, and Bevacizumab:An Observational Health Data Sciences and Informatics Network Study
Purpose: To characterize the incidence of kidney failure associated with intravitreal anti-VEGF exposure; and compare the risk of kidney failure in patients treated with ranibizumab, aflibercept, or bevacizumab. Design: Retrospective cohort study across 12 databases in the Observational Health Data Sciences and Informatics (OHDSI) network. Subjects: Subjects aged ≥ 18 years with ≥ 3 monthly intravitreal anti-VEGF medications for a blinding disease (diabetic retinopathy, diabetic macular edema, exudative age-related macular degeneration, or retinal vein occlusion). Methods: The standardized incidence proportions and rates of kidney failure while on treatment with anti-VEGF were calculated. For each comparison (e.g., aflibercept versus ranibizumab), patients from each group were matched 1:1 using propensity scores. Cox proportional hazards models were used to estimate the risk of kidney failure while on treatment. A random effects meta-analysis was performed to combine each database's hazard ratio (HR) estimate into a single network-wide estimate. Main Outcome Measures: Incidence of kidney failure while on anti-VEGF treatment, and time from cohort entry to kidney failure. Results: Of the 6.1 million patients with blinding diseases, 37 189 who received ranibizumab, 39 447 aflibercept, and 163 611 bevacizumab were included; the total treatment exposure time was 161 724 person-years. The average standardized incidence proportion of kidney failure was 678 per 100 000 persons (range, 0–2389), and incidence rate 742 per 100 000 person-years (range, 0–2661). The meta-analysis HR of kidney failure comparing aflibercept with ranibizumab was 1.01 (95% confidence interval [CI], 0.70–1.47; P = 0.45), ranibizumab with bevacizumab 0.95 (95% CI, 0.68–1.32; P = 0.62), and aflibercept with bevacizumab 0.95 (95% CI, 0.65–1.39; P = 0.60). Conclusions: There was no substantially different relative risk of kidney failure between those who received ranibizumab, bevacizumab, or aflibercept. Practicing ophthalmologists and nephrologists should be aware of the risk of kidney failure among patients receiving intravitreal anti-VEGF medications and that there is little empirical evidence to preferentially choose among the specific intravitreal anti-VEGF agents. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.</p
- …