Home care: a safe and attractive alternative to inpatient administration of intensive chemotherapies.

OBJECTIVE: The objective of this study was to evaluate feasibility, safety, perception, and costs of home care for the administration of intensive chemotherapies. METHODS: Patients receiving sequential chemotherapy in an inpatient setting, living within 30 km of the hospital, and having a relative to care for them were offered home care treatment. Chemotherapy was administered by a portable, programmable pump via an implantable catheter. The main endpoints were safety, patient's quality of life [Functional Living Index-Cancer (FLIC)], satisfaction of patients and relatives, and costs. RESULTS: Two hundred days of home care were analysed, representing a total of 46 treatment cycles of intensive chemotherapy in 17 patients. Two cycles were complicated by technical problems that required hospitalisation for a total of 5 days. Three major medical complications (heart failure, angina pectoris, and major allergic reaction) could be managed at home. Grades 1 and 2 nausea and vomiting occurring in 36% of patients could be treated at home. FLIC scores remained constant throughout the study. All patients rated home care as very satisfactory or satisfactory. Patient benefits of home care included increased comfort and freedom. Relatives acknowledged better tolerance and less asthenia of the patient. Home care resulted in a 53% cost benefit compared to hospital treatment (420 ± 120/day vs. 896 ± 165/day). CONCLUSION: Administration of intensive chemotherapy regimens at home was feasible and safe. Quality of life was not affected; satisfaction of patients and relatives was very high. A psychosocial benefit was observed for patients and relatives. Furthermore, a cost-benefit of home care compared to hospital treatment was demonstrated.

Comparison and evaluation of states of health

Starting from a finite or countable set of states of health, and assumingthe existence of an objective transitive preference relation on that set,we propose a way of performing interpersonal comparisons of states ofhealth. In so doing, we first consider the population divided into types,and consider that two individuals of a different type have a comparablestate of health whenever they sit at the same centile of their respectivetype. A way of comparing and evaluating states of health for differentgroups is then proposed and rationalized. This can be viewed as both analternative and an extension of the traditional QALY approach.

Percepció de dificultat i esforç en la mobilització de persones dependents, en el seu entorn domiciliari, per part dels seus cuidadors, abans i després de la utilització de llençols lliscants

Les persones amb dependència necessiten ajuda en la mobilització al llit, que suposa un esforç per a la persona cuidadora. La percepció de dificultat en dur a terme aquestes tasques pot afectar negativament la qualitat de vida de les persones cuidadores i també la de les persones dependents. L’objectiu d’aquest estudi va ser investigar si la utilització de superfícies de reducció de la fricció (tipus llençols lliscants) redueix la dificultat percebuda per les persones cuidadores i les persones dependents en la mobilització al llit. Mètodes: es va dur a terme un estudi quasi experimental a domicili en una mostra seleccionada a conveniència de 12 persones amb dependència i els seus cuidadors en diverses localitats. Es va avaluar la percepció de dificultat en la mobilització per part dels cuidadors i les persones dependents abans i després d’una intervenció formativa simultània a la utilització de llençols lliscants. Resultats: el perfil del cuidador és el d’una dona de mitjana edat amb una relació filial amb la persona dependent i sense formació específica en mètodes de mobilització de persones dependents. El perfil de la persona dependent és el d’una dona major de 80 anys amb una gran dependència que necessita ajuda de la persona que la cuida en les maniobres de redreçament i trasllat al llit. En una escala de percepció de la dificultat de 0 a 10, les mitjanes de les puntuacions observades en els cuidadors abans de la intervenció van ser de 6,9 (DE: 3,1) en el redreçament cap amunt i de 7,1 (DE: 3,1) en el trasllat lateral; després de la intervenció van ser d’1,25 (DE: 1,8) en el redreçament cap amunt i d’1,45 (DE: 1,6) en la mobilització lateral. En la mateixa escala, les mitjanes de les puntuacions observades en les persones dependents abans de la intervenció van ser de 8,6 (DE: 2,3) en el redreçament cap amunt i de 8,6 (DE: 2,3) en el trasllat cap als costats, i després de la intervenció van ser de 2 (DE: 2,6) en els redreçaments cap amunt i de 2 (DE: 2,6) en els trasllats cap als costats. Comparant les puntuacions d’abans i després de la intervenció, observem que la dificultat percebuda per part dels cuidadors de les persones dependents va disminuir de manera significativa (p & 0,001); en les persones dependents també va disminuir, però la disminució no va arribar a ser significativa (p = 0,057). Conclusions: els resultats observats mostren que la utilització de llençols lliscants millora la qualitat de vida dels cuidadors, mesurada per la percepció de la dificultat en les maniobres de mobilització al llit. Així mateix, la seva utilització pot contribuir a un millor envelliment actiu. Caldria fer estudis que permetin quantificar l’esforç físic necessari i el cost-benefici que suposa la utilització d’aquests dispositius.

Aggregation and errors in management accounting

Il est important pour les entreprises de compresser les informations détaillées dans des sets d'information plus compréhensibles. Au chapitre 1, je résume et structure la littérature sur le sujet « agrégation d'informations » en contrôle de gestion. Je récapitule l'analyse coûts-bénéfices que les comptables internes doivent considérer quand ils décident des niveaux optimaux d'agrégation d'informations. Au-delà de la perspective fondamentale du contenu d'information, les entreprises doivent aussi prendre en considération des perspectives cogni- tives et comportementales. Je développe ces aspects en faisant la part entre la comptabilité analytique, les budgets et plans, et la mesure de la performance. Au chapitre 2, je focalise sur un biais spécifique qui se crée lorsque les informations incertaines sont agrégées. Pour les budgets et plans, des entreprises doivent estimer les espérances des coûts et des durées des projets, car l'espérance est la seule mesure de tendance centrale qui est linéaire. A la différence de l'espérance, des mesures comme le mode ou la médiane ne peuvent pas être simplement additionnés. En considérant la forme spécifique de distributions des coûts et des durées, l'addition des modes ou des médianes résultera en une sous-estimation. Par le biais de deux expériences, je remarque que les participants tendent à estimer le mode au lieu de l'espérance résultant en une distorsion énorme de l'estimati¬on des coûts et des durées des projets. Je présente également une stratégie afin d'atténuer partiellement ce biais. Au chapitre 3, j'effectue une étude expérimentale pour comparer deux approches d'esti¬mation du temps qui sont utilisées en comptabilité analytique, spécifiquement « coûts basés sur les activités (ABC) traditionnelles » et « time driven ABC » (TD-ABC). Au contraire des affirmations soutenues par les défenseurs de l'approche TD-ABC, je constate que cette dernière n'est pas nécessairement appropriée pour les calculs de capacité. Par contre, je démontre que le TD-ABC est plus approprié pour les allocations de coûts que l'approche ABC traditionnelle. - It is essential for organizations to compress detailed sets of information into more comprehensi¬ve sets, thereby, establishing sharp data compression and good decision-making. In chapter 1, I review and structure the literature on information aggregation in management accounting research. I outline the cost-benefit trade-off that management accountants need to consider when they decide on the optimal levels of information aggregation. Beyond the fundamental information content perspective, organizations also have to account for cognitive and behavi¬oral perspectives. I elaborate on these aspects differentiating between research in cost accounti¬ng, budgeting and planning, and performance measurement. In chapter 2, I focus on a specific bias that arises when probabilistic information is aggregated. In budgeting and planning, for example, organizations need to estimate mean costs and durations of projects, as the mean is the only measure of central tendency that is linear. Different from the mean, measures such as the mode or median cannot simply be added up. Given the specific shape of cost and duration distributions, estimating mode or median values will result in underestimations of total project costs and durations. In two experiments, I find that participants tend to estimate mode values rather than mean values resulting in large distortions of estimates for total project costs and durations. I also provide a strategy that partly mitigates this bias. In the third chapter, I conduct an experimental study to compare two approaches to time estimation for cost accounting, i.e., traditional activity-based costing (ABC) and time-driven ABC (TD-ABC). Contrary to claims made by proponents of TD-ABC, I find that TD-ABC is not necessarily suitable for capacity computations. However, I also provide evidence that TD-ABC seems better suitable for cost allocations than traditional ABC.

The efficiency of different estimation methods of hydro-physical limits

The soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study area, measurement uncertainty, cost, effort and labour invested. In this paper, the efficiency of different methods for determining hydro-physical limits is evaluated by using indices that allow for the calculation of efficiency in terms of effort and cost. The analysis evaluates both direct determination methods (pressure plate - PP and water activity meter - WAM) and indirect estimation methods (pedotransfer functions - PTFs). The PTFs must be validated for the area of interest before use, but the time and cost associated with this validation are not included in the cost of analysis. Compared to the other methods, the combined use of PP and WAM to determine hydro-physical limits differs significantly in time and cost required and quality of information. For direct methods, increasing sample size significantly reduces cost and time. This paper assesses the effectiveness of combining a general analysis based on efficiency indices and more specific analyses based on the different influencing factors, which were considered separately so as not to mask potential benefits or drawbacks that are not evidenced in efficiency estimation.

Economics of dialysis dependence following renal replacement therapy for critically ill acute kidney injury patients.

BACKGROUND: The obective of this study was to perform a cost-effectiveness analysis comparing intermittent with continuous renal replacement therapy (IRRT versus CRRT) as initial therapy for acute kidney injury (AKI) in the intensive care unit (ICU). METHODS: Assuming some patients would potentially be eligible for either modality, we modeled life year gained, the quality-adjusted life years (QALYs) and healthcare costs for a cohort of 1000 IRRT patients and a cohort of 1000 CRRT patients. We used a 1-year, 5-year and a lifetime horizon. A Markov model with two health states for AKI survivors was designed: dialysis dependence and dialysis independence. We applied Weibull regression from published estimates to fit survival curves for CRRT and IRRT patients and to fit the proportion of dialysis dependence among CRRT and IRRT survivors. We then applied a risk ratio reported in a large retrospective cohort study to the fitted CRRT estimates in order to determine the proportion of dialysis dependence for IRRT survivors. We conducted sensitivity analyses based on a range of differences for daily implementation cost between CRRT and IRRT (base case: CRRT day $632 more expensive than IRRT day; range from $200 to $1000) and a range of risk ratios for dialysis dependence for CRRT as compared with IRRT (from 0.65 to 0.95; base case: 0.80). RESULTS: Continuous renal replacement therapy was associated with a marginally greater gain in QALY as compared with IRRT (1.093 versus 1.078). Despite higher upfront costs for CRRT in the ICU ($4046 for CRRT versus $1423 for IRRT in average), the 5-year total cost including the cost of dialysis dependence was lower for CRRT ($37 780 for CRRT versus $39 448 for IRRT on average). The base case incremental cost-effectiveness analysis showed that CRRT dominated IRRT. This dominance was confirmed by extensive sensitivity analysis. CONCLUSIONS: Initial CRRT is cost-effective compared with initial IRRT by reducing the rate of long-term dialysis dependence among critically ill AKI survivors.

Genetic evidence for female-biased dispersal and gene flow in a polygynous primate.

Many models of sex-biased dispersal predict that the direction of sex-bias depends upon a species' mating system. In agreement with this, almost all polygynous mammals show male-biased dispersal whereas largely monogamous birds show female-biased dispersal (FBD). The hamadryas baboon (Papio hamadryas hamadryas) is polygynous and so dispersal is predicted to be male biased, as is found in all other baboon subspecies, but there are conflicting field data showing both female and male dispersal. Using 19 autosomal genetic markers genotyped in baboons from four Saudi Arabian populations, we found strong evidence for FBD in post-dispersal adults but not, as expected, in pre-dispersal infants and young juveniles, when we compared male and female: population structure (F(st)), inbreeding (F(is)), relatedness (r), and the mean assignment index (mAIc). Furthermore, we found evidence for female-biased gene flow as population genetic structure (F(st)), was about four times higher for the paternally inherited Y, than for either autosomal markers or for maternally inherited mtDNA. These results contradict the direction of sex-bias predicted by the mating system and show that FBD has evolved recently from an ancestral state of male-biased dispersal. We suggest that the cost-benefit balance of dispersal to males and females is tightly linked to the unique hierarchical social structure of hamadryas baboons and that dispersal and social organization have coevolved.

Bentonite Treatment for Economical Dust Reduction on Limestone Surfaced Secondary Roads, HR-351, 1995

This research project was directed at laboratory and field evaluation of sodium montmorillonite clay (Bentonite) as a dust palliative for limestone surfaced secondary roads. It was postulated that the electrically charged surfaces (negative) of the clay particles could interact with the charged surfaces (positive) of the limestone and act as a bonding agent to agglomerate fine (-#200) particulates, and also to bond the fine particulates to larger (+#200) limestone particles. One mile test roads were constructed in Tama, Appanoose, and Hancock counties in Iowa using Bentonite treatment levels (by weight of aggregate) ranging from 3.0 to 12.0%. Construction was accomplished by adding dry Bentonite to the surfacing material and then dry road mixing. The soda ash/water solution (dispersing agent) was spray applied and the treated surfacing material wet mixed by motor graders to a consistency of 2 to 3 inch slump concrete. Two motor graders working in tandem provided rapid mixing. Following wet mixing the material was surface spread and compacted by local traffic. Quantitative and qualitative periodic evaluations and testing of the test roads was conducted with respect to dust generation, crust development, roughness, and braking characteristics. As the Bentonite treatment level increased dust generation decreased. From a cost/benefit standpoint, an optimum level of treatment is about 8% (by weight of aggregate). For roads with light traffic, one application at this treatment level resulted in a 60-70% average dust reduction in the first season, 40-50% in the second season, and 20-30% in the third season. Crust development was rated at two times better than untreated control sections. No discernible trend was evident with respect to roughness. There was no evident difference in any of the test sections with respect to braking distance and braking handling characteristics, under wet surface conditions compared to the control sections. Chloride treatments are more effective in dust reduction in the short term (3-4 months). Bentonite treatment is capable of dust reduction over the long term (2-3 seasons). Normal maintenance blading operations can be used on Bentonite treated areas. Soda ash dispersed Bentonite treatment is estimated to be more than twice as cost effective per percent dust reduction than conventional chloride treatments, with respect to time. However, the disadvantage is that there is not the initial dramatic reduction in dust generation as with the chloride treatment. Although dust is reduced significantly after treatment there is still dust being generated. Video evidence indicates that the dust cloud in the Bentonite treated sections does not rise as high, or spread as wide as the cloud in the untreated section. It also settles faster than the cloud in the untreated section. This is considered important for driving safety of following traffic, and for nuisance dust invasion of residences and residential areas. The Bentonite appears to be functioning as a bonding agent.

Impact de la prophylaxie hormonale sur les fractures du fémur proximal des femmes postménopausiques: une étude de simulation. [Impact of hormonal prevention on fractures of the proximal femur in postmenopausal women: a simulation study].

A simulation model of the effects of hormone replacement therapy (HRT) on hip fractures and their consequences is based on a population of 100,000 post-menopausal women. This cohort is confronted with literature derived probabilities of cancers (endometrium or breast, which are contra-indications to HRT), hip fracture, disability requiring nursing home or home care, and death. Administration of HRT for life prevents 55,5% of hip fractures, 22,6% of years with home care and 4,4% of years in nursing homes. If HRT is administered for 15 years, these results are 15,5%, 10% and 2,2%, respectively. A slight gain in life expectancy is observed for both durations of HRT. The net financial loss in the simulated population is 222 million Swiss Francs (cost/benefit ratio 1.25) for lifelong administration of HRT, and 153 million Swiss Francs (cost/benefit ratio 1.42) if HRT is administered during 15 years.

Conservation of the Eurasian Lynx (Lynx lynx) in a fragmented landscape - habitat models, dispersal and potential distribution

Abstract: The expansion of a recovering population - whether re-introduced or spontaneously returning - is shaped by (i) biological (intrinsic) factors such as the land tenure system or dispersal, (ii) the distribution and availability of resources (e.g. prey), (iii) habitat and landscape features, and (iv) human attitudes and activities. In order to develop efficient conservation and recovery strategies, we need to understand all these factors and to predict the potential distribution and explore ways to reach it. An increased number of lynx in the north-western Swiss Alps in the nineties lead to a new controversy about the return of this cat. When the large carnivores were given legal protection in many European countries, most organizations and individuals promoting their protection did not foresee the consequences. Management plans describing how to handle conflicts with large predators are needed to find a balance between "overabundance" and extinction. Wildlife and conservation biologists need to evaluate the various threats confronting populations so that adequate management decisions can be taken. I developed a GIS probability model for the lynx, based on habitat information and radio-telemetry data from the Swiss Jura Mountains, in order to predict the potential distribution of the lynx in this mountain range, which is presently only partly occupied by lynx. Three of the 18 variables tested for each square kilometre describing land use, vegetation, and topography, qualified to predict the probability of lynx presence. The resulting map was evaluated with data from dispersing subadult lynx. Young lynx that were not able to establish home ranges in what was identified as good lynx habitat did not survive their first year of independence, whereas the only one that died in good lynx habitat was illegally killed. Radio-telemetry fixes are often used as input data to calibrate habitat models. Radio-telemetry is the only way to gather accurate and unbiased data on habitat use of elusive larger terrestrial mammals. However, it is time consuming and expensive, and can therefore only be applied in limited areas. Habitat models extrapolated over large areas can in turn be problematic, as habitat characteristics and availability may change from one area to the other. I analysed the predictive power of Ecological Niche Factor Analysis (ENFA) in Switzerland with the lynx as focal species. According to my results, the optimal sampling strategy to predict species distribution in an Alpine area lacking available data would be to pool presence cells from contrasted regions (Jura Mountains, Alps), whereas in regions with a low ecological variance (Jura Mountains), only local presence cells should be used for the calibration of the model. Dispersal influences the dynamics and persistence of populations, the distribution and abundance of species, and gives the communities and ecosystems their characteristic texture in space and time. Between 1988 and 2001, the spatio-temporal behaviour of subadult Eurasian lynx in two re-introduced populations in Switzerland was studied, based on 39 juvenile lynx of which 24 were radio-tagged to understand the factors influencing dispersal. Subadults become independent from their mothers at the age of 8-11 months. No sex bias neither in the dispersal rate nor in the distance moved was detected. Lynx are conservative dispersers, compared to bear and wolf, and settled within or close to known lynx occurrences. Dispersal distances reached in the high lynx density population - shorter than those reported in other Eurasian lynx studies - are limited by habitat restriction hindering connections with neighbouring metapopulations. I postulated that high lynx density would lead to an expansion of the population and validated my predictions with data from the north-western Swiss Alps where about 1995 a strong increase in lynx abundance took place. The general hypothesis that high population density will foster the expansion of the population was not confirmed. This has consequences for the re-introduction and recovery of carnivores in a fragmented landscape. To establish a strong source population in one place might not be an optimal strategy. Rather, population nuclei should be founded in several neighbouring patches. Exchange between established neighbouring subpopulations will later on take place, as adult lynx show a higher propensity to cross barriers than subadults. To estimate the potential population size of the lynx in the Jura Mountains and to assess possible corridors between this population and adjacent areas, I adapted a habitat probability model for lynx distribution in the Jura Mountains with new environmental data and extrapolated it over the entire mountain range. The model predicts a breeding population ranging from 74-101 individuals and from 51-79 individuals when continuous habitat patches < 50 km2 are disregarded. The Jura Mountains could once be part of a metapopulation, as potential corridors exist to the adjoining areas (Alps, Vosges Mountains, and Black Forest). Monitoring of the population size, spatial expansion, and the genetic surveillance in the Jura Mountains must be continued, as the status of the population is still critical. ENFA was used to predict the potential distribution of lynx in the Alps. The resulting model divided the Alps into 37 suitable habitat patches ranging from 50 to 18,711 km2, covering a total area of about 93,600 km2. When using the range of lynx densities found in field studies in Switzerland, the Alps could host a population of 961 to 1,827 residents. The results of the cost-distance analysis revealed that all patches were within the reach of dispersing lynx, as the connection costs were in the range of dispersal cost of radio-tagged subadult lynx moving through unfavorable habitat. Thus, the whole Alps could once be considered as a metapopulation. But experience suggests that only few disperser will cross unsuitable areas and barriers. This low migration rate may seldom allow the spontaneous foundation of new populations in unsettled areas. As an alternative to natural dispersal, artificial transfer of individuals across the barriers should be considered. Wildlife biologists can play a crucial role in developing adaptive management experiments to help managers learning by trial. The case of the lynx in Switzerland is a good example of a fruitful cooperation between wildlife biologists, managers, decision makers and politician in an adaptive management process. This cooperation resulted in a Lynx Management Plan which was implemented in 2000 and updated in 2004 to give the cantons directives on how to handle lynx-related problems. This plan was put into practice e.g. in regard to translocation of lynx into unsettled areas. Résumé: L'expansion d'une population en phase de recolonisation, qu'elle soit issue de réintroductions ou d'un retour naturel dépend 1) de facteurs biologiques tels que le système social et le mode de dispersion, 2) de la distribution et la disponibilité des ressources (proies), 3) de l'habitat et des éléments du paysage, 4) de l'acceptation de l'espèce par la population locale et des activités humaines. Afin de pouvoir développer des stratégies efficaces de conservation et de favoriser la recolonisation, chacun de ces facteurs doit être pris en compte. En plus, la distribution potentielle de l'espèce doit pouvoir être déterminée et enfin, toutes les possibilités pour atteindre les objectifs, examinées. La phase de haute densité que la population de lynx a connue dans les années nonante dans le nord-ouest des Alpes suisses a donné lieu à une controverse assez vive. La protection du lynx dans de nombreux pays européens, promue par différentes organisations, a entraîné des conséquences inattendues; ces dernières montrent que tout plan de gestion doit impérativement indiquer des pistes quant à la manière de gérer les conflits, tout en trouvant un équilibre entre l'extinction et la surabondance de l'espèce. Les biologistes de la conservation et de la faune sauvage doivent pour cela évaluer les différents risques encourus par les populations de lynx, afin de pouvoir rapidement prendre les meilleuresmdécisions de gestion. Un modèle d'habitat pour le lynx, basé sur des caractéristiques de l'habitat et des données radio télémétriques collectées dans la chaîne du Jura, a été élaboré afin de prédire la distribution potentielle dans cette région, qui n'est que partiellement occupée par l'espèce. Trois des 18 variables testées, décrivant pour chaque kilomètre carré l'utilisation du sol, la végétation ainsi que la topographie, ont été retenues pour déterminer la probabilité de présence du lynx. La carte qui en résulte a été comparée aux données télémétriques de lynx subadultes en phase de dispersion. Les jeunes qui n'ont pas pu établir leur domaine vital dans l'habitat favorable prédit par le modèle n'ont pas survécu leur première année d'indépendance alors que le seul individu qui est mort dans l'habitat favorable a été braconné. Les données radio-télémétriques sont souvent utilisées pour l'étalonnage de modèles d'habitat. C'est un des seuls moyens à disposition qui permette de récolter des données non biaisées et précises sur l'occupation de l'habitat par des mammifères terrestres aux moeurs discrètes. Mais ces méthodes de- mandent un important investissement en moyens financiers et en temps et peuvent, de ce fait, n'être appliquées qu'à des zones limitées. Les modèles d'habitat sont ainsi souvent extrapolés à de grandes surfaces malgré le risque d'imprécision, qui résulte des variations des caractéristiques et de la disponibilité de l'habitat d'une zone à l'autre. Le pouvoir de prédiction de l'Analyse Ecologique de la Niche (AEN) dans les zones où les données de présence n'ont pas été prises en compte dans le calibrage du modèle a été analysée dans le cas du lynx en Suisse. D'après les résultats obtenus, la meilleure mé- thode pour prédire la distribution du lynx dans une zone alpine dépourvue d'indices de présence est de combiner des données provenant de régions contrastées (Alpes, Jura). Par contre, seules les données sur la présence locale de l'espèce doivent être utilisées pour les zones présentant une faible variance écologique tel que le Jura. La dispersion influence la dynamique et la stabilité des populations, la distribution et l'abondance des espèces et détermine les caractéristiques spatiales et temporelles des communautés vivantes et des écosystèmes. Entre 1988 et 2001, le comportement spatio-temporel de lynx eurasiens subadultes de deux populations réintroduites en Suisse a été étudié, basé sur le suivi de 39 individus juvéniles dont 24 étaient munis d'un collier émetteur, afin de déterminer les facteurs qui influencent la dispersion. Les subadultes se sont séparés de leur mère à l'âge de 8 à 11 mois. Le sexe n'a pas eu d'influence sur le nombre d'individus ayant dispersés et la distance parcourue au cours de la dispersion. Comparé à l'ours et au loup, le lynx reste très modéré dans ses mouvements de dispersion. Tous les individus ayant dispersés se sont établis à proximité ou dans des zones déjà occupées par des lynx. Les distances parcourues lors de la dispersion ont été plus courtes pour la population en phase de haute densité que celles relevées par les autres études de dispersion du lynx eurasien. Les zones d'habitat peu favorables et les barrières qui interrompent la connectivité entre les populations sont les principales entraves aux déplacements, lors de la dispersion. Dans un premier temps, nous avons fait l'hypothèse que les phases de haute densité favorisaient l'expansion des populations. Mais cette hypothèse a été infirmée par les résultats issus du suivi des lynx réalisé dans le nord-ouest des Alpes, où la population connaissait une phase de haute densité depuis 1995. Ce constat est important pour la conservation d'une population de carnivores dans un habitat fragmenté. Ainsi, instaurer une forte population source à un seul endroit n'est pas forcément la stratégie la plus judicieuse. Il est préférable d'établir des noyaux de populations dans des régions voisines où l'habitat est favorable. Des échanges entre des populations avoisinantes pourront avoir lieu par la suite car les lynx adultes sont plus enclins à franchir les barrières qui entravent leurs déplacements que les individus subadultes. Afin d'estimer la taille de la population de lynx dans le Jura et de déterminer les corridors potentiels entre cette région et les zones avoisinantes, un modèle d'habitat a été utilisé, basé sur un nouveau jeu de variables environnementales et extrapolé à l'ensemble du Jura. Le modèle prédit une population reproductrice de 74 à 101 individus et de 51 à 79 individus lorsque les surfaces d'habitat d'un seul tenant de moins de 50 km2 sont soustraites. Comme des corridors potentiels existent effectivement entre le Jura et les régions avoisinantes (Alpes, Vosges, et Forêt Noire), le Jura pourrait faire partie à l'avenir d'une métapopulation, lorsque les zones avoisinantes seront colonisées par l'espèce. La surveillance de la taille de la population, de son expansion spatiale et de sa structure génétique doit être maintenue car le statut de cette population est encore critique. L'AEN a également été utilisée pour prédire l'habitat favorable du lynx dans les Alpes. Le modèle qui en résulte divise les Alpes en 37 sous-unités d'habitat favorable dont la surface varie de 50 à 18'711 km2, pour une superficie totale de 93'600 km2. En utilisant le spectre des densités observées dans les études radio-télémétriques effectuées en Suisse, les Alpes pourraient accueillir une population de lynx résidents variant de 961 à 1'827 individus. Les résultats des analyses de connectivité montrent que les sous-unités d'habitat favorable se situent à des distances telles que le coût de la dispersion pour l'espèce est admissible. L'ensemble des Alpes pourrait donc un jour former une métapopulation. Mais l'expérience montre que très peu d'individus traverseront des habitats peu favorables et des barrières au cours de leur dispersion. Ce faible taux de migration rendra difficile toute nouvelle implantation de populations dans des zones inoccupées. Une solution alternative existe cependant : transférer artificiellement des individus d'une zone à l'autre. Les biologistes spécialistes de la faune sauvage peuvent jouer un rôle important et complémentaire pour les gestionnaires de la faune, en les aidant à mener des expériences de gestion par essai. Le cas du lynx en Suisse est un bel exemple d'une collaboration fructueuse entre biologistes de la faune sauvage, gestionnaires, organes décisionnaires et politiciens. Cette coopération a permis l'élaboration du Concept Lynx Suisse qui est entré en vigueur en 2000 et remis à jour en 2004. Ce plan donne des directives aux cantons pour appréhender la problématique du lynx. Il y a déjà eu des applications concrètes sur le terrain, notamment par des translocations d'individus dans des zones encore inoccupées.

Economic evaluation of the levonorgestrel-releasing intrauterine system for the treatment of dysfunctional uterine bleeding in Spain

To compare the cost and effectiveness of the levonorgestrel-releasing intrauterine system (LNG-IUS) versus combined oral contraception (COC) and progestogens (PROG) in first-line treatment of dysfunctional uterine bleeding (DUB) in Spain. STUDY DESIGN: A cost-effectiveness and cost-utility analysis of LNG-IUS, COC and PROG was carried out using a Markov model based on clinical data from the literature and expert opinion. The population studied were women with a previous diagnosis of idiopathic heavy menstrual bleeding. The analysis was performed from the National Health System perspective, discounting both costs and future effects at 3%. In addition, a sensitivity analysis (univariate and probabilistic) was conducted. RESULTS: The results show that the greater efficacy of LNG-IUS translates into a gain of 1.92 and 3.89 symptom-free months (SFM) after six months of treatment versus COC and PROG, respectively (which represents an increase of 33% and 60% of symptom-free time). Regarding costs, LNG-IUS produces savings of 174.2-309.95 and 230.54-577.61 versus COC and PROG, respectively, after 6 months-5 years. Apart from cost savings and gains in SFM, quality-adjusted life months (QALM) are also favourable to LNG-IUS in all scenarios, with a range of gains between 1 and 2 QALM compared to COC and PROG. CONCLUSIONS: The results indicate that first-line use of the LNG-IUS is the dominant therapeutic option (less costly and more effective) in comparison with first-line use of COC or PROG for the treatment of DUB in Spain. LNG-IUS as first line is also the option that provides greatest health-related quality of life to patients.

Bone mineral density (BMD), micro-architecture estimation (TBS) and vertebral fracture assessment (VFA) extracted from a single DXA device in combination with clinical risk factors improve significantly the identification of women at high risk of fracture.

Osteoporosis (OP) is a systemic skeletal disease characterized by a low bone mineral density (BMD) and a micro-architectural (MA) deterioration. Clinical risk factors (CRF) are often used as a MA approximation. MA is yet evaluable in daily practice by the trabecular bone score (TBS) measure. TBS is very simple to obtain, by reanalyzing a lumbar DXA-scan. TBS has proven to have diagnosis and prognosis values, partially independent of CRF and BMD. The aim of the OsteoLaus cohort is to combine in daily practice the CRF and the information given by DXA (BMD, TBS and vertebral fracture assessment (VFA)) to better identify women at high fracture risk. The OsteoLaus cohort (1400 women 50 to 80 years living in Lausanne, Switzerland) started in 2010. This study is derived from the cohort COLAUS who started in Lausanne in 2003. The main goal of COLAUS is to obtain information on the epidemiology and genetic determinants of cardiovascular risk in 6700 men and women. CRF for OP, bone ultrasound of the heel, lumbar spine and hip BMD, VFA by DXA and MA evaluation by TBS are recorded in OsteoLaus. Preliminary results are reported. We included 631 women: mean age 67.4 ± 6.7 years, BMI 26.1 ± 4.6, mean lumbar spine BMD 0.943 ± 0.168 (T-score − 1.4 SD), and TBS 1.271 ± 0.103. As expected, correlation between BMD and site matched TBS is low (r2 = 0.16). Prevalence of VFx grade 2/3, major OP Fx and all OP Fx is 8.4%, 17.0% and 26.0% respectively. Age- and BMI-adjusted ORs (per SD decrease) are 1.8 (1.2-2.5), 1.6 (1.2-2.1), and 1.3 (1.1-1.6) for BMD for the different categories of fractures and 2.0 (1.4-3.0), 1.9 (1.4-2.5), and 1.4 (1.1-1.7) for TBS respectively. Only 32 to 37% of women with OP Fx have a BMD < − 2.5 SD or a TBS < 1.200. If we combine a BMD < − 2.5 SD or a TBS < 1.200, 54 to 60% of women with an osteoporotic Fx are identified. As in the already published studies, these preliminary results confirm the partial independence between BMD and TBS. More importantly, a combination of TBS subsequent to BMD increases significantly the identification of women with prevalent OP Fx which would have been misclassified by BMD alone. For the first time we are able to have complementary information about fracture (VFA), density (BMD), micro- and macro architecture (TBS and HAS) from a simple, low ionizing radiation and cheap device: DXA. Such complementary information is very useful for the patient in the daily practice and moreover will likely have an impact on cost effectiveness analysis.

Toimittajaverkoston ja päähankkijan rajapintojen yhdistäminen

Kansainvälisen kaupan ja kanssakäymisen lisääntyminen onpakottanut veturiyritykset verkostoitumaan toisten yritysten kanssa, joustavuuden, tehokkuuden ja kilpailukyvyn parantamiseksi. Tällöin tarvitaan nopeita sähköisen tiedonsiirronvälineitä tilaus- ja toimitusprosesseissa. Tutkimuksen tavoitteena oli saada kehitysmalli kansainvälisen päähankkijan, järjestelmätoimittajan ja toimittajaverkoston välille sähköisen tiedonsiirron kehittämiseksi sellaiselle tasolle, missä voidaan saavuttaa kokonaiskustannushyöty koko toimittajaketjulle. Tutkimuksen mukaan järjestelmätoimittajan ja päähankkijan sähköinen tiedonsiirto oli valtaosassa tutkituista järjestelmätoimittajista hyvällä tasolla. Monessa verkoston yrityksessä sähköisen tiedonsiirron kehitys oli pysähtynyt järjestelmätoimittajatasolle, eikä sitä ole kehitetty edelleen toimittajaverkostoon päin. Ainoastaan yhden tutkimuksessa mukana olleen järjestelmätoimittajan kehityssuunnitelma vastaa päähankkijan asettamia lähitulevaisuuden tavoitteita sähköisen tiedonsiirron kehittämisestä toimittajaverkostossa. Tutkimuksessa havaittiin, ettei sähköinen tiedonsiirtokehity toimittajaverkostossa, elleivät järjestelmätoimittajat ota suurempaa vastuuta sen kehittämiseksi omassa toimittajaverkostossa. Tutkimustulosten perusteella kaikkien osapuolien päähankkijan, järjestelmätoimittajan ja toimittajaverkoston aktiivinen tuki sähköisen tiedonsiirron kehittämiselle parantaa kokonaiskustannusten hallinnan ja imuohjauksen kautta kilpailukykyä.

Three essays in dynamic corporate finance

The three essays constituting this thesis focus on financing and cash management policy. The first essay aims to shed light on why firms issue debt so conservatively. In particular, it examines the effects of shareholder and creditor protection on capital structure choices. It starts by building a contingent claims model where financing policy results from a trade-off between tax benefits, contracting costs and agency costs. In this setup, controlling shareholders can divert part of the firms' cash ows as private benefits at the expense of minority share- holders. In addition, shareholders as a class can behave strategically at the time of default leading to deviations from the absolute priority rule. The analysis demonstrates that investor protection is a first order determinant of firms' financing choices and that conflicts of interests between firm claimholders may help explain the level and cross-sectional variation of observed leverage ratios. The second essay focuses on the practical relevance of agency conflicts. De- spite the theoretical development of the literature on agency conflicts and firm policy choices, the magnitude of manager-shareholder conflicts is still an open question. This essay proposes a methodology for quantifying these agency conflicts. To do so, it examines the impact of managerial entrenchment on corporate financing decisions. It builds a dynamic contingent claims model in which managers do not act in the best interest of shareholders, but rather pursue private benefits at the expense of shareholders. Managers have discretion over financing and dividend policies. However, shareholders can remove the manager at a cost. The analysis demonstrates that entrenched managers restructure less frequently and issue less debt than optimal for shareholders. I take the model to the data and use observed financing choices to provide firm-specific estimates of the degree of managerial entrenchment. Using structural econometrics, I find costs of control challenges of 2-7% on average (.8-5% at median). The estimates of the agency costs vary with variables that one expects to determine managerial incentives. In addition, these costs are sufficient to resolve the low- and zero-leverage puzzles and explain the time series of observed leverage ratios. Finally, the analysis shows that governance mechanisms significantly affect the value of control and firms' financing decisions. The third essay is concerned with the documented time trend in corporate cash holdings by Bates, Kahle and Stulz (BKS,2003). BKS find that firms' cash holdings double from 10% to 20% over the 1980 to 2005 period. This essay provides an explanation of this phenomenon by examining the effects of product market competition on firms' cash holdings in the presence of financial constraints. It develops a real options model in which cash holdings may be used to cover unexpected operating losses and avoid inefficient closure. The model generates new predictions relating cash holdings to firm and industry characteristics such as the intensity of competition, cash flow volatility, or financing constraints. The empirical examination of the model shows strong support of model's predictions. In addition, it shows that the time trend in cash holdings documented by BKS can be at least partly attributed to a competition effect.

Economic evaluation of the levonorgestrel-releasing intrauterine system for the treatment of dysfunctional uterine bleeding in Spain

To compare the cost and effectiveness of the levonorgestrel-releasing intrauterine system (LNG-IUS) versus combined oral contraception (COC) and progestogens (PROG) in first-line treatment of dysfunctional uterine bleeding (DUB) in Spain. STUDY DESIGN: A cost-effectiveness and cost-utility analysis of LNG-IUS, COC and PROG was carried out using a Markov model based on clinical data from the literature and expert opinion. The population studied were women with a previous diagnosis of idiopathic heavy menstrual bleeding. The analysis was performed from the National Health System perspective, discounting both costs and future effects at 3%. In addition, a sensitivity analysis (univariate and probabilistic) was conducted. RESULTS: The results show that the greater efficacy of LNG-IUS translates into a gain of 1.92 and 3.89 symptom-free months (SFM) after six months of treatment versus COC and PROG, respectively (which represents an increase of 33% and 60% of symptom-free time). Regarding costs, LNG-IUS produces savings of 174.2-309.95 and 230.54-577.61 versus COC and PROG, respectively, after 6 months-5 years. Apart from cost savings and gains in SFM, quality-adjusted life months (QALM) are also favourable to LNG-IUS in all scenarios, with a range of gains between 1 and 2 QALM compared to COC and PROG. CONCLUSIONS: The results indicate that first-line use of the LNG-IUS is the dominant therapeutic option (less costly and more effective) in comparison with first-line use of COC or PROG for the treatment of DUB in Spain. LNG-IUS as first line is also the option that provides greatest health-related quality of life to patients.