Networks of social interactions are the substrate upon which civilizations are built. Often, we create new bonds with people that we like or feel that our relationships are damaged through the ...intervention of third parties. Despite their importance and the huge impact that these processes have in our lives, quantitative scientific understanding of them is still in its infancy, mainly due to the difficulty of collecting large datasets of social networks including individual attributes. In this work, we present a thorough study of real social networks of 13 schools, with more than 3,000 students and 60,000 declared positive and negative relations, including tests for personal traits of all the students. We introduce a metric -- the `triadic influence' -- that measures the influence of nearest-neighbors in the relationships of their contacts. We use neural networks to predict the relationships and to extract the probability that two students are friends or enemies depending on their personal attributes or the triadic influence. We alternatively use a high-dimensional embedding of the network structure to also predict the relationships. Remarkably, the triadic influence (a simple one-dimensional metric) achieves the highest accuracy at predicting the relationship between two students. We postulate that the probabilities extracted from the neural networks -- functions of the triadic influence and the personalities of the students -- control the evolution of real social networks, opening a new avenue for the quantitative study of these systems.
To compare, in the Spanish setting, 2 drugs for adults with rheumatoid artritis (RA): leflunomide and subcutaneous methotrexate (SC). The high price of methotrexate SC compared with traditional ...presentations of methotrexate justifies conducting an economic evaluation comparing it with leflunomide.
The analysis considered the annual costs of the drugs and their effectiveness, measured with a number needed to treat (NNT) approach, considering both the ACR20 and ACR50 criteria for effectiveness. Data about efficacy and dosage were derived from the clinical trial US310, a randomized, doble-blinded controlled trial, which compared efficacy and safety of leflunomide (20mg/daily) versus placebo versus methotrexate (7.5–15mg/weekly) in 482 patients with active RA. Data about use of medical resources for drug monitoring (visits to rheumatologists and diagnostic procedures) were derived from the manufacturerś summary of product characteristics. Direct costs (drugs and monitoring) were obtained from 2 Spanish databases. The analysis has been performed under the Spanish National Health System perspective.
Using the ACR20 criteria, the NNT with leflunomide and methotrexate are 4 (95% CI, 2.56–7.71) and 5 (95% CI, 3.03–14.3) respectively. Using the ACR50 criteria, NNT are 4 (95% CI, 2.72-6.54) and 7 (95% CI, 4.03–19.3). In the case of leflunomide, annual treatment costs per patient-year equals €1793.30; in the case of methotrexate total treatment costs amounts to €2149.20
Combining these results the cost of a controlled patient according to ACR20 would amount €7173 for leflunomide and €10 746 for methotrexate SC. Results considering ACR50 are €7173 and €15 044 for leflunomide and methotrexate respectively.
Comparar 2 farmacos para la artritis reumatoide (AR): leflunomida y metotrexato subcutaneo (s.c.) (jeringas precargadas), considerando tanto costes anuales de tratamiento como la efectividad medida a traves del numero de pacientes que es necesario tratar (NNT).
Los datos de eficacia y dosis fueron extraidos del ensayo clinico US310, ensayo aleatorizado y doble ciego, que tuvo por objetivo comparar la eficacia y la seguridad del tratamiento a 12 meses con leflunomida (20mg/dia) frente a placebo y metotrexato (7,5–15mg/semana) en 482 pacientes con AR activa. La informacion sobre los actos medicos para los seguimientos de control se obtuvo de la ficha tecnica del producto. El estudio de costes se ha realizado con la perspectiva del Sistema Nacional de Salud espanol.
Considerando el criterio de ACR20, el NNT de leflunomida es 4 (intervalo de confianza IC del 95%, 2,56-7,71) y el de metotrexato s.c., 5 (IC del 95%, 3,03–14,3); para el criterio de ACR50, el NNT de leflunomida es 4 (IC del 95%, 2,72–6,54) y el de metotrexato s.c., 7 (IC del 95%, 4,03–19,3). El coste anual del farmaco fue 1.112,52 euros para la leflunomida y 1.438,91 euros para el metotrexato s.c. Los costes anuales de monitorizacion fueron 680,76 euros para la leflunomida y 710,26 euros para el metotrexato s.c.
Combinando la informacion, el coste de un paciente respondedor segun ACR20 seria de 7.173 euros con leflunomida y 10.746 euros con metotrexato s.c.; los resultados considerando ACR50 oscilarian entre los 7.173 euros para la leflunomida y 15.044 euros para el metotrexato s.c.
Being able to predict preoperatively the difficulty of a cholecystectomy can increase safety and improve results. However, there is a need to reach a consensus on the definition of a cholecystectomy ...as “difficult”. The aim of this study is to achieve a national expert consensus on this issue.
A two-round Delphi study was performed. Based on the previous literature, history of biliary pathology, preoperative clinical, analytical, and radiological data, and intraoperative findings were selected as variables of interest and rated on a Likert scale.
Inter-rater agreement was defined as “unanimous” when 100% of the participants gave an item the same rating on the Likert scale; as “consensus” when ≥80% agreed; as “majority” when the agreement was ≥70%. The delta of change between the two rounds was calculated.
After the two rounds, the criteria that reached “consensus” were bile duct injury (96.77%), non-evident anatomy (93.55%), Mirizzi syndrome (93.55%), severe inflammation of Calot's triangle (90.32%), conversion to laparotomy (87.10%), time since last acute cholecystitis (83.87%), scleroatrophic gallbladder (80.65%) and pericholecystic abscess (80.65%).
The ability to predict difficulty in cholecystectomy offers important advantages in terms of surgical safety. As a preliminary step, the items that define a surgical procedure as difficult should be established. Standardization of the criteria can provide scores to predict difficulty both preoperatively and intraoperatively, and thus allow the comparison of groups of similar difficulty.
•There is not a clear definition of “difficult” cholecystectomy.•National survey to reach consensus on the definition of difficult cholecystectomy.•Predicting the difficulty offers major advantages in terms of surgical safety.
La amplia nómina de autores que firman el presente artículo dan forma al equipo multidisciplinar que en 1995 inició un ambicioso proyecto, subvencionado por la Junta de Castilla y León, denominado ...«Trabajos de Documentación y Estudio del Arte Rupestre en el Karst de Ojo Guareña». El avance de sus primeros trabajos está recogido en el siguiente texto y fue presentado al Primer Congreso de Arqueología Burgalesa (1998), mas, al no haberse publicado éste, sigue aún inédito. Su interés, y de forma especial la continuidad de la investigación, aconseja a los autores su edición en Espacio, Tiempo y Forma con vistas a una mayor difusión del proyecto y, con ello, a un mejor conocimiento de la grafía rupestre de las galerías subterráneas del norte de la provincia de Burgos.The wide number of researchers who sign the present añide joined in the multi-discipline team that started an ambitious project, which was sponsored by the regional authority: Junta de Castilla y León, called «Records and Research on Cave Art at the karst in Ojo Guareña». The deveiopment of thelr first researches Is shown in the present Ítem and it was also presented in the First Burgos Archaeology Congress (1998), although it is still unavailable since it has never been published. Both, the Importance of its contents and specially the continuity of the research led its authors to publish this article in Espacio, Tiempo y Forma so that the project could be widely known and, at the same time, provide a better knowledge of rock graphics in the underground galleries which can be found in the north of Burgos province.
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