1,720,993 research outputs found
The new comorbidity index: A development and validation study
No full textNår prognosen af en sygdom studeres, er det vist, at komorbide sygdomme har en effekt på resultatet. For at justere for denne effekt kan et komorbiditets indeks bruges. Det indeks, der oftest anvendes, er Charlsons komorbiditetsindeks, som blev udviklet i 1987 på en lille kohorte af patienter fra New York Hospital.Formålet med dette speciale er at undersøge Charlson komorbiditetsindeksets evne til at prædiktere dødeligheden i en kohorte af lungebetændelsespatienter, og at udvikle samt validere et nyt komorbiditetsindeks.Vi anvender en kohorte af hospitalsindlagte lungebetændelsespatienter fra Landspatient Registeret. Vi validerer Charlson komorbiditets indekset ved at inkludere det i en logistisk regression med 30 dages dødelighed som udfald og dernæst vurdere dets præstation.Både logistisk regression, naive Bayes og klassifikations træer blev brugt til at udvikle et nyt indeks. Da den logistiske regression blev brugt, opdaterede vi vægtene på Charlsons originale sygdomme, inkluderede vi tre nye sygdomme, inkluderede vi førstegrads-interaktionsled og en variable for 'tid siden diagnose'.Som et alternativ til den logistiske regression blev naive Bayes og klassifikationstræer brugt. Indekserne udviklet på baggrund af disse metoder inkluderede de originale Charlson sygdomme samt de tre nye sygdomme.Vi validerede indekserne ved at undersøge deres prædiktionsevne for både 30 dages- og 1 årsdødelighed. Deres rå prædiktionsevne blev vurderet ved hjælp af en Pearson chi i anden test på en frekvenstabel indeholdende indekset og dødeligheden. For at vurdere deres justeret prædiktionsevne blev hvert indeks inkluderet i en logistisk regression justeret for køn og alder.Vores analyser viste, at Charlson komorbiditetsindekset er udmærket til at prædiktere død blandt lundebetændelsespatienter, og derfor er det stadig brugbart.Alle vores indekser præsterede udemærket og de fleste af dem bedre end Charlson komorbiditetsindekset. Vores analyser viste, at fire af vores indekser var bedre end resten. For disse indekser steg kompleksiteten med prædiktionsevnen. Det at vælge det bedste indeks er derfor en balance mellem prædiktionsevne og enkelhed og afhænger af den enkelte situation.When the prognosis of a disease is studied it has been shown that comorbid diseases have an influence on the outcome. To adjust for this influence a comorbidity index can be used. The most used index is the Charlson comorbidity index, which was developed in 1987 on a small cohort of patients from the medical service at New York Hospital. The aim of this thesis is to investigate the ability of the Charlson comorbidity index to predict mortality on a cohort of pneumonia patients, and to develop and validate a new comorbidity index.We used a cohort of hospitalized pneumonia patients from the Danish National Registry of Patients. We validated the Charlson comorbidity index by including it in a logistic regression with 30 day mortality as an outcome and assessing the performance.Both logistic regression, naive Bayes and classifications trees were used to develop new indexes. When using the logistic regression method we updated the weights on the original Charlson diseases, included three new diseases, included first degree interaction terms and a variable for 'time since diagnosis'.The naive Bayes method and classification trees were used as alternatives to the logistic regression model. Indexes made by these methods included the original Charlson diseases and the three new diseases.We validated the indexes by assessing their performance for both 30 day and 1 year mortality. Their crude performance was assessed by the Pearson chi squared test of a contingency table for the index and mortality. To assess their adjusted performance we included each index in a logistic regression adjusted for sex and age.Our analysis showed that the Charlson comorbidity index predicted death among pneumonia patients well, and therefore it is still usable.All of our developed indexes performed well and most of them better than CCI. Our analysis showed that four of our indexes were better than the rest. For these indexes their complexity increased with performance. Choosing the best index out of these is therefore a balance between performance and simplicity and depends on the situation at hand
Trends in paediatric macrolide use in five European countries - A population-based study
No full textPURPOSE:
The study aims to analyse overall as well as subgroup-specific outpatient paediatric macrolide use in five European countries, including time trends of macrolide prescription rates, and to provide potential targets for future interventions aiming to promote judicious macrolide use.
METHODS:
Macrolide prescription rates per 1000 person years to paediatric outpatients (≤18 years) were calculated using healthcare databases from Denmark, Germany, Italy, The Netherlands and the UK. Poisson regression analysis was used to estimate the influence of increasing calendar year on total macrolide and subgroup-specific prescription rates based on monthly data, adjusted for seasonal variations. Time periods for which data were available varied between 4 (Italy 2007-10, Germany 2005-8) and 10 years (UK 2000-9).
RESULTS:
Paediatric macrolide use in 2008 varied between 199 (Italy) and 47 (Netherlands) prescriptions per 1000 person years. Prescription rates of short-acting macrolides declined significantly in all countries but the UK. The use of intermediate-acting macrolides significantly rose with increasing calendar year in Denmark (rate ratio (RR) = 1.12) and the UK (RR = 1.06), but decreased in Germany (RR = 0.84) and The Netherlands (RR = 0.97). Prescription rates of long-acting agents increased in Denmark (RR = 1.05), The Netherlands (RR = 1.05) and the UK (RR = 1.11) (all trends p < 0.05). The greatest seasonal variations of macrolide use between summer and winter months were observed in Italy and Germany.
CONCLUSIONS:
The observed trend toward increased prescribing of intermediate- and/or long-acting agents might further increase resistance pressure on bacterial pathogens due to their prolonged plasma half-life and broader antibacterial activity. Marked seasonality of prescription rates in the high-utilising countries, Italy and Germany, suggests frequent prescription of macrolides to treat respiratory infections which may be of viral origin
Prescribing pattern of antipsychotic drugs during the years 1996-2010: a population-based database study in Europe with a focus on torsadogenic drugs.
Get PDFINTRODUCTION: Antipsychotic drugs (APDs) are used to treat several mental illnesses. Some APDs have long been known to be associated with QT prolongation, potentially leading to torsades de pointes (TdP) and sudden cardiac death (SCD). In 2005, thioridazine was withdrawn because of the risk of SCD, bringing further attention to the arrhythmogenic potential of APDs. AIM: The aim of the current study was to evaluate the use of APDs in five European countries during the years 1996-2010. METHODS: A cohort study was conducted using prescription/dispensing data from seven healthcare databases [the AARHUS University Hospital Database (Denmark), the German Pharmacoepidemiological Research Database (GePaRD) (Germany), Health Search Database/Thales (HSD) and Emilia Romagna Regional Database (ERD) (Italy), PHARMO Database Network and Integrated Primary Care Information (IPCI) (the Netherlands) and The Health Improvement Network (THIN) (the UK), covering a population of 27 million individuals. The annual prescription rate of APDs was measured overall and for individual medications. APDs were classified as torsadogenic according to the Arizona-CERT list. All analyses were stratified by age, gender and calendar year. RESULTS: A total of 559 276 person-years (PYs) of exposure to APDs was captured. The crude annual prescription rate of APD use ranged from 3.0/1000 PYs in ERD to 7.7/1000 PYs in AARHUS. Among APDs with established torsadogenic potential, thioridazine was the most frequently used medication in the UK. Haloperidol was commonly prescribed in Italy and the Netherlands. The use of APDs with torsadogenic potential was much higher in elderly patients. CONCLUSIONS: Substantial use of APDs with torsadogenic potential has been reported in Europe in recent years, in spite of increasing concerns about their arrhythmogenic potential. This use was even greater in elderly patients, who are at higher risk of SCD
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
