1,737,673 research outputs found
What does validation of cases in electronic record databases mean? The potential contribution of free text
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
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.
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
Status of the physics validation studies using Geant4 in ATLAS
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
Systematic review of the psychometric properties of patient-reported outcome measures for foot and ankle in rheumatoid arthritis
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
Design and validation of a questionnaire to measure research skills: experience with engineering students
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
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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