988 resultados para peaks-over-threshold


Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVES: To determine whether nalmefene combined with psychosocial support is cost-effective compared with psychosocial support alone for reducing alcohol consumption in alcohol-dependent patients with high/very high drinking risk levels (DRLs) as defined by the WHO, and to evaluate the public health benefit of reducing harmful alcohol-attributable diseases, injuries and deaths. DESIGN: Decision modelling using Markov chains compared costs and effects over 5 years. SETTING: The analysis was from the perspective of the National Health Service (NHS) in England and Wales. PARTICIPANTS: The model considered the licensed population for nalmefene, specifically adults with both alcohol dependence and high/very high DRLs, who do not require immediate detoxification and who continue to have high/very high DRLs after initial assessment. DATA SOURCES: We modelled treatment effect using data from three clinical trials for nalmefene (ESENSE 1 (NCT00811720), ESENSE 2 (NCT00812461) and SENSE (NCT00811941)). Baseline characteristics of the model population, treatment resource utilisation and utilities were from these trials. We estimated the number of alcohol-attributable events occurring at different levels of alcohol consumption based on published epidemiological risk-relation studies. Health-related costs were from UK sources. MAIN OUTCOME MEASURES: We measured incremental cost per quality-adjusted life year (QALY) gained and number of alcohol-attributable harmful events avoided. RESULTS: Nalmefene in combination with psychosocial support had an incremental cost-effectiveness ratio (ICER) of £5204 per QALY gained, and was therefore cost-effective at the £20,000 per QALY gained decision threshold. Sensitivity analyses showed that the conclusion was robust. Nalmefene plus psychosocial support led to the avoidance of 7179 alcohol-attributable diseases/injuries and 309 deaths per 100,000 patients compared to psychosocial support alone over the course of 5 years. CONCLUSIONS: Nalmefene can be seen as a cost-effective treatment for alcohol dependence, with substantial public health benefits. TRIAL REGISTRATION NUMBERS: This cost-effectiveness analysis was developed based on data from three randomised clinical trials: ESENSE 1 (NCT00811720), ESENSE 2 (NCT00812461) and SENSE (NCT00811941).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

On the basis of French individual data, this paper compares the effects of demographic change, changes in morbidity and changes in practices on the growth in health expenditures that occurred between 1992 and 2000. Micro simulations show that the rise in expenditures due to ageing is relatively small and that the impact of changes in practices is times larger. Furthermore, changes in morbidity induce savings which more than offset the increase in spending due to population ageing. [Authors]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Longitudinal entomological surveys were performed in Vila Candelária and adjacent rural locality of Bate Estaca concomitantly with a clinical epidemiologic malaria survey. Vila Candelária is a riverside periurban neighborhood of Porto Velho, capital of the state of Rondônia in the Brazilian Amazon. High anopheline densities were found accompanying the peak of rainfall, as reported in rural areas of the region. Moreover, several minor peaks of anophelines were recorded between the end of the dry season and the beginning of the next rainy season. These secondary peaks were related to permanent anopheline breeding sites resulting from human activities. Malaria transmission is, therefore, observed all over the year. In Vila Candelária, the risk of malaria infection both indoors and outdoors was calculated as being 2 and 10/infecting bites per year per inhabitant respectively. Urban malaria in riverside areas was associated with two factors: (1) high prevalence of asymptomatic carriers in a stable human population and (2) high anopheline densities related to human environmental changes. This association is probably found in other Amazonian urban and suburban communities. The implementation of control measures should include environmental sanitation and better characterization of the role of asymptomatic carriers in malaria transmission.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although the general trend for delaying childbearing is generally viewed as causing infertility, its consequences on the interpregnancy interval have been unknown. A study of birth records for Swiss married women from 1969 to 2006 revealed that the woman's age at first birth has increased from 25.0 to 30.1 years, whereas calculated theoretical interpregnancy intervals after the first and second child decreased from 23.2 to 13 and from 22.4 to 7.9 months, respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction: Accurate registration of the relative timing between the occurrence of sensory events on a sub-second time scale is crucial for both sensory-motor and cognitive functions (Mauk and Buonomano, 2004; Habib, 2000). Support for this assumption comes notably from evidence that temporal processing impairments are implicated in a range of neurological and psychiatric conditions (e.g. Buhusi & Meck, 2005). For instance, deficits in fast auditory temporal integration have been regularly put forward as resulting in phonologic discrimination impairments at the basis of speech comprehension deficits characterizing e.g. dyslexia (Habib, 2000). At least two aspects of the brain mechanisms of temporal order judgment remain unknown. First, it is unknown when during the course of stimulus processing a temporal ,,stamp‟ is established to guide TOJ perception. Second, the extent of interplay between the cerebral hemispheres in engendering accurate TOJ performance is unresolved Methods: We investigated the spatiotemporal brain dynamics of auditory temporal order judgment (aTOJ) using electrical neuroimaging analyses of auditory evoked potentials (AEPs) recorded while participants completed a near-threshold task requiring spatial discrimination of left-right and right-left sound sequences. Results: AEPs to sound pairs modulated topographically as a function of aTOJ accuracy over the 39-77ms post-stimulus period, indicating the engagement of distinct configurations of brain networks during early auditory processing stages. Source estimations revealed that accurate and inaccurate performance were linked to bilateral posterior sylvian regions activity (PSR). However, activity within left, but not right, PSR predicted behavioral performance suggesting that left PSR activity during early encoding phases of pairs of auditory spatial stimuli appears critical for the perception of their order of occurrence. Correlation analyses of source estimations further revealed that activity between left and right PSR was significantly correlated in the inaccurate but not accurate condition, indicating that aTOJ accuracy depends on the functional de-coupling between homotopic PSR areas. Conclusions: These results support a model of temporal order processing wherein behaviorally relevant temporal information - i.e. a temporal 'stamp'- is extracted within the early stages of cortical processes within left PSR but critically modulated by inputs from right PSR. We discuss our results with regard to current models of temporal of temporal order processing, namely gating and latency mechanisms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A case-control study on chronic Chagas heart disease (CCHD) was carried out between 1997 and 2005. Ninety patients over 50 years of age were examined for factors related to (CCHD). Fourty-six patients (51.1%) with Chagas heart disease (anomalous ECG) were assigned to the case group and 44 (48.9%) were included in the control group as carriers of undetermined forms of chronic disease. Social, demographic (age, gender, skin color, area of origin), epidemiological (permanence within an endemic zone, family history of Chagas heart disease or sudden death, physical strain, alcoholism, and smoking), and clinical (systemic hypertension) variables were analyzed. The data set was assessed through single-variable and multivariate analysis. The two factors independently associated with heart disease were age - presence of heart disease being three times higher in patients over 60 years of age (odds ratio, OR: 2.89; confidence interval of 95%: 1.09-7.61) - and family history of Chagas heart disease (OR: 2.833, CI 95%: 1.11-7.23). Systemic hypertension and gender did not prove to hold any association with heart disease, as neither did skin color, but this variable showed low statistical power due to reduced sample size.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Master athletes are often considered to represent the ideal rate of decline of aerobic function; however, most of the studies interested in active elderly people are often limited to people younger than 75. We aimed to determine the physiological adaptations and aerobic fitness in a selected European population of active octogenarians during maximal and submaximal exercise tests. Aerobic capacity was measured during maximal incremental tests on treadmill (TR) and cycle-ergometer (CE) and functional capacity during a 6-minute walk test (6-MWT) in 17 subjects aged 81.2 +/- 0.8 years. Pulmonary gas exchange and heart rate (HR) were continuously measured during the different exercise tests. Maximal oxygen consumption (V.O (2max)) on TR and CE was significantly higher than predicted values (TR: 28.7 +/- 1.2 vs. 17 +/- 0.5 ml . kg (-1) . min (-1); CE: 23 +/- 1.2 vs. 16 +/- 0.6 ml . kg (-1) . min (-1) for measured and predicted values respectively). V.O (2max) and HR (max), as well as V.O (2) and HR at the ventilatory threshold (V.O (2)T (V.E) and HR T (V.E)) were significantly higher on TR than on CE (HR (max): 144 +/- 4 vs. 138 +/- 4 bpm; V.O (2)T (V.E): 22.5 +/- 0.8 vs. 17.7 +/- 0.9 ml . kg (-1) . min (-1) for TR and CE respectively). V.O (2)T (V.E) and HR T (V.E) on TR were equivalent to V.O (2) and HR measured during the 6-MWT. HR T (V.E) on TR and mean HR during the 6-MWT were strongly correlated (R = 0.82, p < 0.01). Maintenance of regular physical activity provides high aerobic fitness, in octogenarians, as was shown by the higher values of our subjects in comparison to predicted values. Moreover, the close relation between the intensity developed at T (V.E) on TR and 6-MWT could support the idea that a walk test is a submaximal test performed at high intensity that could provide a basis for exercise prescription in an individualized manner in active elderly people.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dominance hierarchies pervade animal societies. Within a static social environment, in which group size and composition are unchanged, an individual's hierarchy rank results from intrinsic (e.g. body size) and extrinsic (e.g. previous experiences) factors. Little is known, however, about how dominance relationships are formed and maintained when group size and composition are dynamic. Using a fusion-fission protocol, we fused groups of previously isolated shore crabs (Carcinus maenas) into larger groups, and then restored groups to their original size and composition. Pre-fusion hierarchies formed independently of individuals' sizes, and were maintained within a static group via winner/loser effects. Post-fusion hierarchies differed from pre-fusion ones; losing fights during fusion led to a decline in an individual's rank between pre- and post-fusion conditions, while spending time being aggressive during fusion led to an improvement in rank. In post-fusion tanks, larger individuals achieved better ranks than smaller individuals. In conclusion, dominance hierarchies in crabs represent a complex combination of intrinsic and extrinsic factors, in which experiences from previous groups can carry over to affect current competitive interactions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Letrozole, an aromatase inhibitor, is ineffective in the presence of ovarian estrogen production. Two subpopulations of apparently postmenopausal women might derive reduced benefit from letrozole due to residual or returning ovarian activity: younger women (who have the potential for residual subclinical ovarian estrogen production), and those with chemotherapy-induced menopause who may experience return of ovarian function. In these situations tamoxifen may be preferable to an aromatase inhibitor. Among 4,922 patients allocated to the monotherapy arms (5 years of letrozole or tamoxifen) in the BIG 1-98 trial we identified two relevant subpopulations: patients with potential residual ovarian function, defined as having natural menopause, treated without adjuvant or neoadjuvant chemotherapy and age ≤ 55 years (n = 641); and those with chemotherapy-induced menopause (n = 105). Neither of the subpopulations examined showed treatment effects differing from the trial population as a whole (interaction P values are 0.23 and 0.62, respectively). Indeed, both among the 641 patients aged ≤ 55 years with natural menopause and no chemotherapy (HR 0.77 [0.51, 1.16]) and among the 105 patients with chemotherapy-induced menopause (HR 0.51 [0.19, 1.39]), the disease-free survival (DFS) point estimate favoring letrozole was marginally more beneficial than in the trial as a whole (HR 0.84 [0.74, 0.95]). Contrary to our initial concern, DFS results for young postmenopausal patients who did not receive chemotherapy and patients with chemotherapy-induced menopause parallel the letrozole benefit seen in the BIG 1-98 population as a whole. These data support the use of letrozole even in such patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Humoral factors play an important role in the control of exercise hyperpnea. The role of neuromechanical ventilatory factors, however, is still being investigated. We tested the hypothesis that the afferents of the thoracopulmonary system, and consequently of the neuromechanical ventilatory loop, have an influence on the kinetics of oxygen consumption (VO2), carbon dioxide output (VCO2), and ventilation (VE) during moderate intensity exercise. We did this by comparing the ventilatory time constants (tau) of exercise with and without an inspiratory load. Fourteen healthy, trained men (age 22.6 +/- 3.2 yr) performed a continuous incremental cycle exercise test to determine maximal oxygen uptake (VO2max = 55.2 +/- 5.8 ml x min(-1) x kg(-1)). On another day, after unloaded warm-up they performed randomized constant-load tests at 40% of their VO2max for 8 min, one with and the other without an inspiratory threshold load of 15 cmH2O. Ventilatory variables were obtained breath by breath. Phase 2 ventilatory kinetics (VO2, VCO2, and VE) could be described in all cases by a monoexponential function. The bootstrap method revealed small coefficients of variation for the model parameters, indicating an accurate determination for all parameters. Paired Student's t-tests showed that the addition of the inspiratory resistance significantly increased the tau during phase 2 of VO2 (43.1 +/- 8.6 vs. 60.9 +/- 14.1 s; P < 0.001), VCO2 (60.3 +/- 17.6 vs. 84.5 +/- 18.1 s; P < 0.001) and VE (59.4 +/- 16.1 vs. 85.9 +/- 17.1 s; P < 0.001). The average rise in tau was 41.3% for VO2, 40.1% for VCO2, and 44.6% for VE. The tau changes indicated that neuromechanical ventilatory factors play a role in the ventilatory response to moderate exercise.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ces trente dernières années, on note en Suisse une augmentation significative de l'incidence du syndrome de détresse respiratoire (SDR) chez le nouveau-né (NN), touchant particulièrement les enfants avec un poids de naissance >2500 g. En même temps, le taux des césariennes (CS) s'est aussi accru. Une explication pour une éventuelle corrélation entre les deux évolutions est une augmentation en particulier des CS électives qui ont tendance à être planifiées à un terme précoce pour éviter la mise en travail spontanée. Suite à cela, le foetus est privé de différents mécanismes qui favorisent l'adaptation pulmonaire périnatale. Les bénéfices réels de la CS sur la morbidité tant foetale que maternelle ne doivent pas faire oublier que la CS est un facteur de risque pour le SDR du NN. Ce risque peut être diminué efficacement en planifiant une CS élective après 39 semaines révolues. In Switzerland, the rate of respiratory distress in neonates needing hospitalization has doubled over the last thirty years, concerning in particular babies weighing more than 2500 g. In the same time, the rate of Caesarean section (CS) has also multiplied. We suppose that a link between the two evolutions might be the increase of elective CS. They tend to be planned early at term to avoid the onset of spontaneous labour As a consequence, the foetus is deprived of different mechanisms helping pulmonary transition around birth. The potential benefits of CS regarding morbidity of foetus and mother should not overshadow that CS is a significant risk factor for respiratory problems of the neonate. This risk could be dramatically decreased by planning elective CS only after completed 39 weeks of gestation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A recent study defines a new network plane: the knowledge plane. The incorporation of the knowledge plane over the network allows having more accurate information of the current and future network states. In this paper, the introduction and management of the network reliability information in the knowledge plane is proposed in order to improve the quality of service with protection routing algorithms in GMPLS over WDM networks. Different experiments prove the efficiency and scalability of the proposed scheme in terms of the percentage of resources used to protect the network

Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION Higher and lower cerebral perfusion pressure (CPP) thresholds have been proposed to improve brain tissue oxygen pressure (PtiO2) and outcome. We study the distribution of hypoxic PtiO2 samples at different CPP thresholds, using prospective multimodality monitoring in patients with severe traumatic brain injury. METHODS This is a prospective observational study of 22 severely head injured patients admitted to a neurosurgical critical care unit from whom multimodality data was collected during standard management directed at improving intracranial pressure, CPP and PtiO2. Local PtiO2 was continuously measured in uninjured areas and snapshot samples were collected hourly and analyzed in relation to simultaneous CPP. Other variables that influence tissue oxygen availability, mainly arterial oxygen saturation, end tidal carbon dioxide, body temperature and effective hemoglobin, were also monitored to keep them stable in order to avoid non-ischemic hypoxia. RESULTS Our main results indicate that half of PtiO2 samples were at risk of hypoxia (defined by a PtiO2 equal to or less than 15 mmHg) when CPP was below 60 mmHg, and that this percentage decreased to 25% and 10% when CPP was between 60 and 70 mmHg and above 70 mmHg, respectively (p < 0.01). CONCLUSION Our study indicates that the risk of brain tissue hypoxia in severely head injured patients could be really high when CPP is below the normally recommended threshold of 60 mmHg, is still elevated when CPP is slightly over it, but decreases at CPP values above it.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thanks to decades of research, gait analysis has become an efficient tool. However, mainly due to the price of the motion capture systems, standard gait laboratories have the capability to measure only a few consecutive steps of ground walking. Recently, wearable systems were proposed to measure human motion without volume limitation. Although accurate, these systems are incompatible with most of existing calibration procedures and several years of research will be necessary for their validation. A new approach consisting of using a stationary system with a small capture volume for the calibration procedure and then to measure gait using a wearable system could be very advantageous. It could benefit from the knowledge related to stationary systems, allow long distance monitoring and provide new descriptive parameters. The aim of this study was to demonstrate the potential of this approach. Thus, a combined system was proposed to measure the 3D lower body joints angles and segmental angular velocities. It was then assessed in terms of reliability towards the calibration procedure, repeatability and concurrent validity. The dispersion of the joint angles across calibrations was comparable to those of stationary systems and good reliability was obtained for the angular velocities. The repeatability results confirmed that mean cycle kinematics of long distance walks could be used for subjects' comparison and pointed out an interest for the variability between cycles. Finally, kinematics differences were observed between participants with different ankle conditions. In conclusion, this study demonstrated the potential of a mixed approach for human movement analysis.