1,722,097 research outputs found
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
Health Economic Models for Relapsing-Remitting Multiple Sclerosis
Full text linkThe structure of the economic models to assess the cost-effectiveness of disease-modifying treatments (DMTs) for relapsing-remitting multiple sclerosis (RRMS) has converged over time. The clinical course of the disease is characterized by changes in disability measured by the Expanded Disability Status Scale (EDSS) and the occurrence of relapse over time. In this thesis, I demonstrated that the time to complete the Timed 25-Foot Walk (T25FW) test for ambulatory function significantly contributes additional information on health utility in people with RRMS and secondary-progressive MS (SPMS), otherwise not captured by EDSS and relapses. These findings support the use of T25FW to supplement the EDSS and relapses in the characterization of the clinical course of the disease and the accrual of quality-adjusted life-years (QALYs) in economic models of DMTs for RRMS. A new economic modeling framework was developed using discretely integrated condition event (DICE) simulation to assess the cost-effectiveness of DMTs for RRMS, with the addition of T25FW, while appropriately capturing the correlation of changes between the EDSS, T25FW, and relapses over time. Comparing the cost-effectiveness of two DMTs when T25FW was accounted vs. not accounted for demonstrated that the addition of T25FW has an important impact on QALYs and the cost-effectiveness of DMTs
Pharmacoeconomics of cardiovascular disease prevention
Full text linkIn this thesis, some of the methodological challenges in simulating and synthesizing pharmacoeconomic evidence in cardiovascular disease (CVD) prevention were assessed and potential solutions to those challenges were proposed. This includes a set of recommendations for enhancing the robustness of pharmacoeconomic analyses that apply CVD risk prediction models. The application of these recommendations was also explored in a simplified model of primary CVD prevention with antihypertensives. Another challenging issue relates to the robustness of evidence on the health-related quality of life (HRQoL) values used in pharmacoeconomic analyses. Here, evidence-synthesis was suggested as a relevant approach to, where appropriate, synthesize HRQoL values in specific CVD disorders as well as to indicate the level of heterogeneity across those values and possibly its sources. As an example, evidence-synthesis of instrument-specific HRQoL values in coronary heart disease and its underlying disease-forms was explored. In this study large heterogeneity within and between the instrument-specific values and inherent uncertainty if applied within pharmacoeconomic analysis, were found. This thesis also derives pharmacoeconomic evidence on the use of oral anticoagulants (i.e. vitamin K antagonists (VKAs) and novel oral anticoagulants (NOACs) e.g. apixaban, dabigatran) for secondary CVD prevention that may have direct societal relevance and implications in the Dutch setting. Firstly, optimizing the standard anticoagulant care with VKAs was explored. Secondly, the health and economic consequences associated with the use of apixaban for the prevention of stroke in non-valvular atrial fibrillation, and dabigatran for treatment and prevention of venous thromboembolism indicated that both apixaban and dabigatran were favourable alternatives to treatment with VKAs. In conclusion, several studies in this thesis emphasize that standardizing methodological requirements and recommendations for conducting and reporting pharmacoeconomic studies in CVD prevention including the ones proposed in this thesis may enhance the quality and validity of pharmacoeconomic evidence and reduce possible bias. Furthermore, this thesis provides pharmacoeconomic evidence that NOACs may present a valuable alternative to VKAs for thromboprophylaxis in the Dutch setting
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
Health-economics of interventions aimed at infectious diseases: dynamic modeling inevitable for reliable decision making
Full text linkTegenwoordig bevatten de meeste gezondheidseconomische evaluaties zogenaamde modellen om de potentiële kosten en baten te schatten van verschillende medische interventies. Echter, infectieziekten vragen vaak een andere aanpak in vergelijking tot andere ziektegebieden om tot betrouwbare uitkomsten te komen. Dit is het gevolg van de unieke eigenschap van (de meeste) infectieziekten dat ze van-mens-tot-mens overdraagbaar zijn, waardoor eventuele herd-immunity effecten (indirecte immuniteit van niet-beschermde individuen als gevolg van een verminderde transmissie in de populatie) een belangrijke rol kunnen spelen.
Dit proefschrift behandelt specifiek het gebruik van verschillende typen modellen om de kosten-effectiviteit van medische interventies gericht op infectieziekten te schatten. Er worden voorbeelden gegeven van zowel ‘statische’ als ‘dynamische’ modellen. In tegenstelling tot statische modellen, worden in dynamische modellen herd-immunity effecten expliciet gemodelleerd. Verder worden de mogelijke gevolgen besproken van het onterecht achterwege laten van herd-immunity effecten.
Om de kwaliteit van gezondheidseconomische studies te waarborgen, zijn er een groot aantal internationale en nationale richtlijnen geformuleerd waaraan zo’n studie moet voldoen. Hoewel modelleren in het algemeen vaak wel aan de orde komt, wordt er zelden iets vermeld over het specifieke gebied van infectieziekten. Dit geldt helaas ook voor de Nederlandse situatie, waardoor beslissingen omtrent vergoeding of implementatie van interventies gericht op infectieziekten soms gebaseerd worden op een onjuiste schatting van de kosten-effectiviteit.
Dit proefschrift wordt dan ook afgesloten met aanbevelingen voor de aanpassing van de nationale richtlijnen voor farmaco-economisch onderzoek. Om tot betrouwbare uitkomsten en uiteindelijk correcte beleidsvoering te komen, is het cruciaal dat infectieziekten dynamisch gemodelleerd worden wanneer herd-immunity effecten optreden.
Novel economic perspectives on prevention and treatment : case studies for paediatric, adolescent and adult infectious and chronic diseases
Full text linkConventionele economische gezondheidsevaluaties richten zich voornamelijk op het rendement van de gezondheidszorg-service-begroting en richten zich zelden op de bredere gevolgen. Het laatste betreft een variatie aan externe, de impact van ziektes op kennis en prestaties op school en ook gedragseff ecten die economische beslissingen kunnen veranderen. Het benaderen van economische evaluaties in de gezondheidszorg in een breed perspectief, welke rekening houdt met een aanzienlijk deel van de bredere voordelen voor welzijn en externe, vereist een nieuwe beeldvorming en nieuwe methoden voor de meting van de voordelen. In Part I van dit proefschrift wordt een kwantitatief analytische methodologisch kader voor het beoordelen van het perspectief van de overheid van de fi scale invloed van gezondheidsproblemen en de fi scale voordelen van preventieve en therapeutische ingrepen (interventies) en immunisaties gepresenteerd. Part II van dit proefschrift betrekt de methode op pediatrische, jongeren en volwassenen immunisering. Part III richt zich op het meten van de bredere voordelen van het behandelen van ADHD in Duitsland. Aanvullend is voorgesteld dat er een overgangsdomein is, welke de micro- en macro-economische verbetering toegeschrijven aan welzijnsveranderingen verbindt. De tegenwoordig beschikbare economische evaluatie methoden laten doorgaans deze gevolgen achterwege, echter; zij kunnen worden aangepast om deze overgangsgevolgen te integreren. Ondanks de kanttekeningen en de praktische uitdagingen voor het uitvoeren van een bredere economische analyse, wordt gesuggereerd dat het verruiming van de voordelen, waar rekening mee wordt gehouden in een economische evaluatie, het waarschijnlijker maakt dat welzijnsmaatregelen met bredere voordelen en/of externe eff ecten, de voorkeur hebben
Evidence-based health care policy in reimbursement decisions : lessons from a series of six equivocal case-studies
Full text linkContext: Health care technological evolution through new drugs, implants and other interventions is a key driver of healthcare spending. Policy makers are currently challenged to strengthen the evidence for and cost-effectiveness of reimbursement decisions, while not reducing the capacity for real innovations. This article examines six cases of reimbursement decision making at the national health insurance authority in Belgium, with outcomes that were contested from an evidence-based perspective in scientific or public media.
Methods: In depth interviews with key stakeholders based on the adapted framework of Davies allowed us to identify the relative impact of clinical and health economic evidence; experience, expertise & judgment; financial impact & resources; values, ideology & political beliefs; habit & tradition; lobbyists & pressure groups; pragmatics & contingencies; media attention; and adoption from other payers & countries.
Findings: Evidence was not the sole criterion on which reimbursement decisions were based. Across six equivocal cases numerous other criteria were perceived to influence reimbursement policy. These included other considerations that stakeholders deemed crucial in this area, such as taking into account the cost to the patient, and managing crisis scenarios. However, negative impacts were also reported, in the form of bypassing regular procedures unnecessarily, dominance of an opinion leader, using information selectively, and influential conflicts of interest.
Conclusions: 'Evidence' and 'negotiation' are both essential inputs of reimbursement policy. Yet, purposely selected equivocal cases in Belgium provide a rich source to learn from and to improve the interaction between both. We formulated policy recommendations to reconcile the impact of all factors identified. A more systematic approach to reimburse new care may be one of many instruments to resolve the budgetary crisis in health care in other countries as well, by separating what is truly innovative and value for money from additional 'waste'
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