1,721,612 research outputs found
DREAM Dutch Randomised Endovascular Aneurysm Management Trial.
Full text linkContains fulltext :
47943.pdf (Publisher’s version ) (Open Access)RU Radboud Universiteit Nijmegen, 09 september 2005Promotores : Blankensteijn, J.D., Grobbee, D.E. Co-promotor : Buskens, E.158 p
Predicting pressure ulcers: cases missed using a new clinical prediction rule
No full textAim. The aim of this paper is to report a study describing patients with pressureulcers that were incorrectly classified as ‘not at risk’ by the prediction rule andcomparing them with patients who were correctly classified as ‘not at risk’.Background. Patients admitted to hospital are at risk of developing pressure ulcers. Although the majority of pressure ulcers can be predicted using a recently developed prediction rule, up to 30% of patients with pressure ulcers may still be misclassified. Methods. Between January 1999 and June 2000 a prospective cohort study was conducted in two large hospitals in the Netherlands. Patients admitted to neurology, internal, surgical, and elder care wards for more than 5 days were included (n ¼ 1229), and were examined weekly. Information on potential prognostic determinants for pressure ulcers mentioned in the literature was recorded. Outcome was defined as occurrence of a pressure ulcer grade 2 or worse during hospital admission.Results. Patients who developed pressure ulcers experienced more problems with ‘friction and shear’ and underwent surgery more often and longer. Also, they were more often admitted because of malignant conditions.Conclusion. We found no specific characteristics that clearly distinguished patients with pressure ulcers that were incorrectly classified as ‘not at risk’ by the prediction rule from patients who were correctly classified as ‘not at risk’. It appears difficult to improve further on the prediction of pressure ulcers using available clinical information
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Identification of older hospitalized patients at risk for functional decline
No full textBetween 30% and 60% of older patients experience functional decline after hospitalization, resulting in a decline in health-related quality of life and autonomy. This is associated with increased risk of readmission, nursing home placement and mortality, increased length of hospital stay and increased need for health care at home. A decreased functional status is a risk factor for the development of geriatric syndromes such as pressure ulcers, falls, delirium, incontinence and further functional decline. Functional decline is mostly defined as a decline in performing the activities of daily living (ADL) and/or instrumental activities of daily living (IADL). This functional decline is not necessarily related to the medical reason for the hospital admission but to the pre-admission health status and the iatrogenic effects of hospitalization. Effective and efficient hospital care for older patients starts with the identification of patients who are at risk for the development of functional decline. Therefore, the aim of this thesis was: To determine a prediction model to identify older patients at risk for functional decline after hospitalization that is easy to use in clinical practice as a first step in the prevention of a loss of function and independence. Functional decline was defined as a decline of at least one point on the Katz ADL index (six items: bathing, dressing, toileting, transferring, eating and the use of incontinence materials) at three months after admission compared to premorbid ADL status. One literature study and four prospective cohort studies (total n=1628) were conducted to develop and validate this prediction model. In the cohort studies the premorbid functional status was measured within 48 hours after admission by interview; patients were asked to describe the situation two weeks prior to admission to eliminate possible effects of the illness causing hospital admission. At follow up, three months after admission, functional status was measured again by telephone interview. This thesis describes the development of a prediction model to identify older patients at risk for functional decline after hospitalization in patients 65 years and older acutely admitted to the general internal wards of three hospitals. The AUC was 0.71, the Hosmer Lemeshow test showed P-value 0.95 indicating a good fitting model. The model was validated in an independent population of internal medicine patients and a population of cardiac surgery patients (both ? 65 years). A scorecard, Identification of Seniors At Risk–Hospitalized Patients (ISAR-HP), was developed based on this model. At threshold 2 (score ?2 indicating high risk for functional decline) the sensitivity, specificity and positive and negative predictive value were 87%, 39%, 43% and 85%, respectively. Pre-admission need for assistance in IADL, use of a walking device, need for assistance in traveling, and no education after age 14 are the predictors of a model to identify older patients at risk for functional decline following hospital admission. This thesis also describes an the implementation of the results of this research into clinical practice, showing how the results of our studies can contribute to safe and targeted care for older hospitalized patients
Genetic risks for cardiovascular diseases
No full textAtherosclerotic cardiovascular disease (CVD), which involves the heart, brain, and peripheral circulation, is a major health problem world-wide. The development of atherosclerosis is a complex process, and several established risk factors are involved. Nevertheless, these established risk factors do not fully explain the occurrence of CVD and further insight is required in factors such as genetic determinants that may identify individuals at risk. In this thesis we worked on the genetic basis of CVD in three parts.
Part one focuses on genes in lipid metabolism pathway and association with CVD. In chapters 2 and 3 we studied the association of the T64A polymorphism in the β3–adrenergic receptor gene (ADRB3) and the peroxisome proliferator-activated receptor gamma-2 (PPARG2) gene polymorphism (P12A), respectively, with coronary heart disease (CHD). Our studies in combination with meta-analyses of previous reports did not provide support for a role of these polymorphisms in CHD risk. In chapter 4 we examined the relationship between the cholesteryl ester transfer protein (CETP) gene polymorphisms and HDL levels and future CHD. Strong associations between higher HDL cholesterol levels and the CETP (-629)A, the CETP I405V V, and the CETP TaqIB B2 alleles and the haplotypes that comprised these alleles were found and the C(-629)A polymorphism was also related to a lower plasma LDL cholesterol. None of the CETP polymorphisms or haplotypes were, however, related to risk of CHD.
Part two focuses on genes in blood pressure regulation pathway and association with CVD. In chapter 5 we showed that presence of the α-adducin Gly460Trp polymorphism increases the risk of stroke, but not the risk of CHD or AMI. This risk is particularly elevated in the presence of systolic hypertension. In chapter 6 we showed in a meta-analysis that the presence of the T allele of the angiotensinogen gene (AGT) M235T polymorphism is associated with increased risk to develop preeclampsia/eclampsia. The latter is a risk factor of development of CVD in later life. We also showed in chapter 7 that this polymorphism is associated with self-reported hypertensive disorders in pregnancy among Caucasian Dutch women. In chapter 8, the pooled odds ratio of the meta-analysis, including our own data, presented evidence that there is an increase in the risk of CHD conferred by the M235T variant of the AGT gene. However, the relevance of this weakly positive overall association remained uncertain because it might be due to various residual biases, including Hardy-Weinberg equilibrium violation and publication biases.
In part three we showed that combination of genetic factors aggregated to a single genetic risk score (GRS) can be used in prediction of incident CHD and the GRS along with conventional risk scores improves the estimation of CHD risk in healthy Dutch women, chapter 9.
We also addressed some considerations with regard to meta-analysis of genetic association studies, forming consortia in this ongoing field, and predictive genetic testing, as well as the new findings in genome-wide association studies and implications of this thesis for clinical practice and future research directions in chapter 10
Early life environment and the developing cardiovascular system
No full textBackground
The dynamics of cardiovascular system development in childhood are still largely unknown. Despite its known sensitivity to small perturbations, it has not been fully elucidated how the cardiovascular system evolves and responds to different stimuli and how these impact the future cardiovascular status. This thesis is basically aimed at exploring the effects of several possible postnatal determinantson the developing cardiovascular system. These early life determinants perhaps immediately cause cardiovascular issues in childhood and contribute to cardiovascular risk in later life. Particular attention is given to childhood conditions that are relevant for low-to-middle income countries, including malnutrition and physical activity. We specifically also look at HIV infection as a model of childhood inflammation which may have profound effects on the developing cardiovascular system.
Methods
Our research questions are addressed through several studies as follows: (1) a pilot/feasibility study of a currently enrolling randomized breastfeeding optimization trial (NCT01566812 )in Indonesia to investigate determinants of breastfeeding planning in pregnant women; (2) a Prospect-European Prospective Investigation into Cancer and Nutrition (Prospect-EPIC) cohort to study the effects of famine exposure in childhood on coronary artery calcifications; (3) An ongoing Wheezing Illnesses Study in Leidsche Rijn (WHISTLER) birth cohort to study the effects of physical activity on childhood vascular characteristics; (4) A cohort of 111 HIV infected and 51 healthy children in Jakarta, Indonesia to study the effects of ART-naive and ART-exposed HIV infection on childhood cardiac status and future cardiovascular risk.
Results
We found that childhood physical activity, famine, and HIV infection seemed to determine future cardiovascular disease risk in adulthood. Higher physical activity level was associated with better vascular properties with thinner intima media thickness. Famine in childhood increased the risk of coronary artery calcification in later life. HIV infection in children was associated with various alterations in heart structure, function, and the conduction system in childhood. Moreover, childhood HIV may increase future cardiovascular disease risk as we found a significantly thicker intima media among treatment naive HIV infected children. Given that breastfeeding is beneficial for childhood vascular properties, we sought the determinants of breastfeeding plan in pregnant women and found that the likelihood of giving exclusive breast feeding was related to mothers being well informed, regardless their social and educational background.
Conclusions
Postnatal influences, including childhood nutrition, physical activity, and morbidities appear to shape cardiovascular development, which not only affects childhood cardiovascular status but also may determine future cardiovascular risk in adulthood
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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