116 research outputs found

    Harnessing repeated measurements of predictor variables for clinical risk prediction: a review of existing methods

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    From Springer Nature via Jisc Publications RouterHistory: received 2020-02-06, accepted 2020-04-28, registration 2020-04-28, pub-electronic 2020-07-09, online 2020-07-09, collection 2020-12Publication status: PublishedFunder: National Institute for Health Research; doi: http://dx.doi.org/10.13039/501100000272; Grant(s): DRF-2018-11-ST2-052Abstract: Background: Clinical prediction models (CPMs) predict the risk of health outcomes for individual patients. The majority of existing CPMs only harness cross-sectional patient information. Incorporating repeated measurements, such as those stored in electronic health records, into CPMs may provide an opportunity to enhance their performance. However, the number and complexity of methodological approaches available could make it difficult for researchers to explore this opportunity. Our objective was to review the literature and summarise existing approaches for harnessing repeated measurements of predictor variables in CPMs, primarily to make this field more accessible for applied researchers. Methods: MEDLINE, Embase and Web of Science were searched for articles reporting the development of a multivariable CPM for individual-level prediction of future binary or time-to-event outcomes and modelling repeated measurements of at least one predictor. Information was extracted on the following: the methodology used, its specific aim, reported advantages and limitations, and software available to apply the method. Results: The search revealed 217 relevant articles. Seven methodological frameworks were identified: time-dependent covariate modelling, generalised estimating equations, landmark analysis, two-stage modelling, joint-modelling, trajectory classification and machine learning. Each of these frameworks satisfies at least one of three aims: to better represent the predictor-outcome relationship over time, to infer a covariate value at a pre-specified time and to account for the effect of covariate change. Conclusions: The applicability of identified methods depends on the motivation for including longitudinal information and the method’s compatibility with the clinical context and available patient data, for both model development and risk estimation in practice

    Biologic treatment response among adults with juvenile idiopathic arthritis: results from the British Society for Rheumatology Biologics Register

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    Abstract Objective. To describe the use of and response to biologic therapies commenced in adults with JIA. Methods. Patients with arthritis onset <16 years were identified from the British Society for Rheumatology Biologics Register for rheumatoid arthritis (BSRBR-RA) and stratified into ILAR JIA subtypes. Patterns of biologic use and treatment persistence were explored, with disability levels (HAQ) and remission rates [28-Joint Disease Activity Score (DAS28)] evaluated at 6 and 12 months. Results. Arthritis with an onset of <16 years was confirmed in 225 patients and the ILAR subtype was determined in 154 (68%). Only 58 (26%) patients had a diagnosis of JIA recorded in the BSRBR-RA. The median age at biologic commencement was 31 years [interquartile range (IQR) 2339] and 76% were female. The biologic therapies were etanercept (49%), infliximab (28%), adalimumab (22%) and anakinra (1%). Fifty per cent of patients received more than one biologic during follow-up (2 agents, n = 64; 53 agents, n = 49). Treatment persistence at 1 year was 78% (95% CI 71%, 82%), falling to 42% (95% CI 34%, 49%) at 5 years. Both the HAQ and DAS28 improved significantly at 6 months, with 21% and 28% of patients in remission (DAS28 < 2.6) at 6 and 12 months, respectively. Conclusion. This study describes patterns and identifies outcomes of biologic use in a national cohort of adults with JIA. With no national guidance currently available in this area, the choice of first biologic was inconsistent, although treatment outcomes were good. These data confirm that biologic therapies are an important treatment option in adults with active JIA in adulthood

    Le projet DYLAN ou les enjeux politiques, cognitifs et stratégiques du plurilinguisme

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    Composed of 19 universities from 12 countries, the Dylan Project is an integrated project (IP) of the 6th Framework Programme of the European Union, under Priority 7 « Citizenship and governance in a knowledge-based society ».The project addresses the core issue underlying topic 3.3.1: establish whether and how a European knowledge based society designed to ensure economic competitiveness and social cohesion can be created within a European Union that is linguistically more diverse than ever. The overarching objectives are to show that, in this respect, the linguistic diversity prevalent in Europe is potentially an asset rather than an obstacle and to identify the conditions under which individual and societal multilingualism can be turned to advantage.It will show in what ways the usage of multilingual repertoires can promote the creation and the transfer of knowledge (cognitive asset) and have an impact on communication control, problem solving and decision making (strategic asset), in the diversity of economic, political and educational contexts

    Optimal Consensus set for nD Fixed Width Annulus Fitting

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    International audienceThis paper presents a method for fitting a nD fixed width spherical shell to a given set of nD points in an image in the presence of noise by maximizing the number of inliers, namely the consensus set. We present an algorithm, that provides the optimal solution(s) within a time complexity O(N n+1 log N) for dimension n, N being the number of points. Our algorithm guarantees optimal solution(s) and has lower complexity than previous known methods

    Genome-Wide Association Study and Gene Expression Analysis Identifies CD84 as a Predictor of Response to Etanercept Therapy in Rheumatoid Arthritis

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    Anti-tumor necrosis factor alpha (anti-TNF) biologic therapy is a widely used treatment for rheumatoid arthritis (RA). It is unknown why some RA patients fail to respond adequately to anti-TNF therapy, which limits the development of clinical biomarkers to predict response or new drugs to target refractory cases. To understand the biological basis of response to anti-TNF therapy, we conducted a genome-wide association study (GWAS) meta-analysis of more than 2 million common variants in 2,706 RA patients from 13 different collections. Patients were treated with one of three anti-TNF medications: etanercept (n = 733), infliximab (n = 894), or adalimumab (n = 1,071). We identified a SNP (rs6427528) at the 1q23 locus that was associated with change in disease activity score (ΔDAS) in the etanercept subset of patients (P = 8×10-8), but not in the infliximab or adalimumab subsets (P>0.05). The SNP is predicted to disrupt transcription factor binding site motifs in the 3′ UTR of an immune-related gene, CD84, and the allele associated with better response to etanercept was associated with higher CD84 gene expression in peripheral blood mononuclear cells (P = 1×10-11 in 228 non-RA patients and P = 0.004 in 132 RA patients). Consistent with the genetic findings, higher CD84 gene expression correlated with lower cross-sectional DAS (P = 0.02, n = 210) and showed a non-significant trend for better ΔDAS in a subset of RA patients with gene expression data (n = 31, etanercept-treated). A small, multi-ethnic replication showed a non-significant trend towards an association among etanercept-treated RA patients of Portuguese ancestry (n = 139, P = 0.4), but no association among patients of Japanese ancestry (n = 151, P = 0.8). Our study demonstrates that an allele associated with response to etanercept therapy is also associated with CD84 gene expression, and further that CD84 expression correlates with disease activity. These findings support a model in which CD84 genotypes and/or expression may serve as a useful biomarker for response to etanercept treatment in RA patients of European ancestry. © 2013 Cui et al

    Automatic segmentation of myocardium from black-blood MR images using entropy and local neighborhood information.

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    By using entropy and local neighborhood information, we present in this study a robust adaptive Gaussian regularizing Chan-Vese (CV) model to segment the myocardium from magnetic resonance images with intensity inhomogeneity. By utilizing the circular Hough transformation (CHT) our model is able to detect epicardial and endocardial contours of the left ventricle (LV) as circles automatically, and the circles are used as the initialization. In the cost functional of our model, the interior and exterior energies are weighted by the entropy to improve the robustness of the evolving curve. Local neighborhood information is used to evolve the level set function to reduce the impact of the heterogeneity inside the regions and to improve the segmentation accuracy. An adaptive window is utilized to reduce the sensitivity to initialization. The Gaussian kernel is used to regularize the level set function, which can not only ensure the smoothness and stability of the level set function, but also eliminate the traditional Euclidean length term and re-initialization. Extensive validation of the proposed method on patient data demonstrates its superior performance over other state-of-the-art methods

    A Multicomponent Animal Virus Isolated from Mosquitoes

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    RNA viruses exhibit a variety of genome organization strategies, including multicomponent genomes in which each segment is packaged separately. Although multicomponent genomes are common among viruses infecting plants and fungi, their prevalence among those infecting animals remains unclear. We characterize a multicomponent RNA virus isolated from mosquitoes, designated Guaico Culex virus (GCXV). GCXV belongs to a diverse clade of segmented viruses (Jingmenvirus) related to the prototypically unsegmented Flaviviridae. The GCXV genome comprises five segments, each of which appears to be separately packaged. The smallest segment is not required for replication, and its presence is variable in natural infections. We also describe a variant of Jingmen tick virus, another Jingmenvirus, sequenced from a Ugandan red colobus monkey, thus expanding the host range of this segmented and likely multicomponent virus group. Collectively, this study provides evidence for the existence of multicomponent animal viruses and their potential relevance for animal and human health.RNA viruses exhibit a variety of genome organization strategies, including multicomponent genomes in which each segment is packaged separately. Although multicomponent genomes are common among viruses infecting plants and fungi, their prevalence among those infecting animals remains unclear. We characterize a multicomponent RNA virus isolated from mosquitoes, designated Guaico Culex virus (GCXV). GCXV belongs to a diverse clade of segmented viruses (Jingmenvirus) related to the prototypically unsegmented Flaviviridae. The GCXV genome comprises five segments, each of which appears to be separately packaged. The smallest segment is not required for replication, and its presence is variable in natural infections. We also describe a variant of Jingmen tick virus, another Jingmenvirus, sequenced from a Ugandan red colobus monkey, thus expanding the host range of this segmented and likely multicomponent virus group. Collectively, this study provides evidence for the existence of multicomponent animal viruses and their potential relevance for animal and human health
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