1,656,980 research outputs found

    What does validation of cases in electronic record databases mean? The potential contribution of free text

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    Electronic health records are increasingly used for research. The definition of cases or endpoints often relies on the use of coded diagnostic data, using a pre-selected group of codes. Validation of these cases, as ‘true’ cases of the disease, is crucial. There are, however, ambiguities in what is meant by validation in the context of electronic records. Validation usually implies comparison of a definition against a gold standard of diagnosis and the ability to identify false negatives (‘true’ cases which were not detected) as well as false positives (detected cases which did not have the condition). We argue that two separate concepts of validation are often conflated in existing studies. Firstly, whether the GP thought the patient was suffering from a particular condition (which we term confirmation or internal validation) and secondly, whether the patient really had the condition (external validation). Few studies have the ability to detect false negatives who have not received a diagnostic code. Natural language processing is likely to open up the use of free text within the electronic record which will facilitate both the validation of the coded diagnosis and searching for false negatives

    Validation Studies of the ATLAS Pixel Detector Control System

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    The ATLAS pixel detector consists of 1744 identical silicon pixel modules arranged in three barrel layers providing coverage for the central region, and three disk layers on either side of the primary interaction point providing coverage of the forward regions. Once deployed into the experiment, the detector will employ optical data transfer, with the requisite powering being provided by a complex system of commercial and custom-made power supplies. However, during normal performance and production tests in the laboratory, only single modules are operated and electrical readout is used. In addition, standard laboratory power supplies are used. In contrast to these normal tests, the data discussed here was obtained from a multi-module assembly which was powered and read out using production items: the optical data path, the final design power supply system using close to final services, and the Detector Control System (DCS). To demonstrate the functionality of the pixel detector system a stepwise transition was made from the normal laboratory readout and power supply systems to the ones foreseen for the experiment, with validation of the data obtained at each transition.Comment: 8 pages, 8 figures, proceedings for the Pixel2005 worksho

    Development and Validation of Targeted Next-Generation Sequencing Panels for Detection of Germline Variants in Inherited Diseases.

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    Context.-The number of targeted next-generation sequencing (NGS) panels for genetic diseases offered by clinical laboratories is rapidly increasing. Before an NGS-based test is implemented in a clinical laboratory, appropriate validation studies are needed to determine the performance characteristics of the test. Objective.-To provide examples of assay design and validation of targeted NGS gene panels for the detection of germline variants associated with inherited disorders. Data Sources.-The approaches used by 2 clinical laboratories for the development and validation of targeted NGS gene panels are described. Important design and validation considerations are examined. Conclusions.-Clinical laboratories must validate performance specifications of each test prior to implementation. Test design specifications and validation data are provided, outlining important steps in validation of targeted NGS panels by clinical diagnostic laboratories

    Systematic review of the psychometric properties of patient-reported outcome measures for foot and ankle in rheumatoid arthritis

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    Background Foot problems and pain are common in patients with rheumatoid arthritis. Patient-reported outcome measures provide a standardized method of capturing patients’ perspectives of their functional status and wellbeing. There are many instruments specific to people with feet affected by rheumatoid arthritis but knowledge of their psychometric validation or methodological quality is lacking Objectives To identify patient-reported outcome measures specific to the foot and ankle and rheumatoid arthritis and investigate their methodological quality and psychometric properties Design Systematic review. Data source : A search was conducted for psychometric or validation studies on patient-reported outcomes in Rheumatoid Arthritis published in different languages, by examining the Pubmed; Scopus, CINAHL; PEDro and Google Scholar databases. Review methods . The systematic review performed was based on the following inclusion criteria: psychometric or clinimetric validation studies on patient-reported outcomes specific to the foot and ankle that included patients with Rheumatoid arthritis. Two authors independently assessed the quality of the studies and extracted datas Results Of the initial 431 studies, fourteen instruments met the inclusion criteria. Significant methodological flaws were detected in most with only SEFAS met the COSMIN quality criteria. Conclusion SEFAS had the best quality and was ranked most appropriate for use with patients living with Rheumatoid Arthriti

    Status of the physics validation studies using Geant4 in ATLAS

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    The new simulation for the ATLAS detector at LHC is performed using Geant4 in a complete OO/C++ environment. In this framework the simulation of the various test beams for the different ATLAS subdetectors offers an excellent opportunity to perform physics validation studies over a wide range of physics domains: the electromagnetic processes, the individual hadronic interactions, the electromagnetic and hadronic signals in calorimeters. The simulation is implemented by paying special attention to all details of the experimental layout and by testing all possible physics processes which may be of relevance to the specific detector under test: the resulting simulation programs are often more detailed than the corresponding Geant3-based simulation suites. In this paper we present relevant features of muon, electron and pion signals in various ATLAS detectors. All remaining discrepancies between Geant4 and test-beam data are currently being addressed and progress is continuous. This work shows that Geant4 is becoming a mature and useful product for simulating specific features of large-scale detector systems.Comment: CHEP '03 proceedings, 7 pages, 22 figure

    Design and validation of a questionnaire to measure research skills: experience with engineering students

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    Universities in Latin American countries are undergoing major changes in its institutional and academic settings. One strategy for continuous improvement of teaching and learning process is the incorporation of methods and teaching aids seeking to develop scientific research skills in students from their undergraduate studies. The aim of this study is the validation of a questionnaire to measure research skills with engineering students. Questionnaire validation was performed by: literature review, semantic and content validation by experts from three Latin American universities, finishing with a factorial and reliability validation. The instrument was applied to 150 students (75,3% men and 24,7% women) that were enrolled in the basic level of engineering. The validated questionnaire has 20 items. The correlations between factors of the instrument, show relationship and dependence between them, indicating the validity of the questionnaire. The reliability of the instrument was calculated using Cronbach's alpha coefficient, which reached a value of .91 in the total scale. The statistical results to validate the questionnaire have been significant, allowing us to propose this experience as a starting point to implement further studies about the development of research skills in university’s students from other areas of knowledgePeer Reviewe

    Cancer biomarker development from basic science to clinical practice

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    The amount of published literature on biomarkers has exponentially increased over the last two decades. Cancer biomarkers are molecules that are either part of tumour cells or secreted by tumour cells. Biomarkers can be used for diagnosing cancer (tumour versus normal and differentiation of subtypes), prognosticating patients (progression free survival and overall survival) and predicting response to therapy. However, very few biomarkers are currently used in clinical practice compared to the unprecedented discovery rate. Some of the examples are: carcino-embryonic antigen (CEA) for colon cancer; prostate specific antigen (PSA) for prostate; and estrogen receptor (ER), progesterone receptor (PR) and HER2 for breast cancer. Cancer biomarkers passes through a series of phases before they are used in clinical practice. First phase in biomarker development is identification of biomarkers which involve discovery, demonstration and qualification. This is followed by validation phase, which includes verification, prioritisation and initial validation. More large-scale and outcome-oriented validation studies expedite the clinical translation of biomarkers by providing a strong ‘evidence base’. The final phase in biomarker development is the routine clinical use of biomarker. In summary, careful identification of biomarkers and then validation in well-designed retrospective and prospective studies is a systematic strategy for developing clinically useful biomarkers
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