130 research outputs found

    Frozen ground and snow cover monitoring in Livingston and Deception islands, Antarctica: preliminary results of the 2015-2019 PERMASNOW project

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    Since 2006, our research team has been establishing in the islands of Livingston and Deception, (South Shetland archipelago, Antarctica) several monitoring stations of the active layer thickness within the international network Circumpolar Active Layer Monitoring (CALM), and the ground thermal regime for the Ground Terrestrial Network-Permafrost (GTN-P). Both networks were developed within the International Permafrost Association (IPA). In the GTN-P stations, in addition to the temperature of the air, soil, and terrain at different depths, the snow thickness is also monitored by snow poles. Since 2006, a delay in the disappearance of the snow layer has been observed, which could explain the variations we observed in the active layer thickness and permafrost temperatures. Therefore, in late 2015 our research group started the PERMASNOW project (2015-2019) to pay attention to the effect of snow cover on ground thermal This project had two different ways to study the snow cover. On the first hand, in early 2017 we deployed new instrumentation, including new time lapse cameras, snow poles with high number of sensors and a complete and complex set of instruments and sensors to configure a snow pack analyzer station providing 32 environmental and snow parameters. We used the data acquired along 2017 and 2018 years with the new instruments, together with the available from all our already existing sensors, to study in detail the snow cover. On the other hand, remote sensing data were used to try to map the snow cover, not only at our monitoring stations but the entire islands in order to map and study the snow cover distribution, as well as to start the way for future permafrost mapping in the entire islands. MODIS-derived surface temperatures and albedo products were used to detect the snow cover and to test the surface temperature. Since cloud presence limited the acquisition of valid observations of MODIS sensor, we also analyzed Terrasar X data to overcome this limitation. Remote sensing data validation required the acquirement of in situ ground-true data, consisting on data from our permanent instruments, as well as ad hoc measurements in the field (snow cover mapping, snow pits, albedo characterization, etc.). Although the project is finished, the data analysis is still ongoing. We present here the different research tasks we are developing as well as the most important results we already obtained about the snow cover. These results confirm how the snow cover duration has been changing in the last years, affecting the ground thermal behavior.info:eu-repo/semantics/publishedVersio

    Pemetrexed disodium in recurrent locally advanced or metastatic squamous cell carcinoma of the head and neck

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    This phase II study determined response rate of patients with locally advanced or metastatic head and neck cancer treated with pemetrexed disodium, a new multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase and glycinamide ribonucleotide formyl transferase. 35 patients with local or metastatic relapse of squamous cell carcinoma of the head and neck (31 male, 4 female; median age 53 years) were treated with pemetrexed 500 mg m2 administered as a 10-minute infusion on day 1 of a 21-day cycle. Patients received 1 to 8 cycles of therapy. 9 patients (26.5%) had an objective response, with a median response duration of 5.6 months (range 2.9–20 months). 15 (44.1%) had stable disease, and 8 (23.5%) had progressive disease. 2 patients were not assessable for response. Median overall survival was 6.4 months (range 0.7–28.1 months; 95% CI: 3.9–7.7 months). 24 patients (68.6%) experienced grade 3/4 neutropenia, with febrile neutropenia in 4 (11.4%). Grade 3/4 anaemia and thrombocytopenia occurred in 11 (34.3%) and 6 (17.1%) patients, respectively. The most frequent non-haematological toxicity was grade 3/4 mucositis (17.1%; 6 patients). In conclusion, pemetrexed is active in squamous cell carcinoma of the head and neck. Although substantial haematological toxicities were experienced by patients, subsequent studies have shown that these toxicities can be proactively managed by folic acid and vitamin B12 supplementation. © 2001 Cancer Research Campaign http://www.bjcancer.co

    A phase II study of docetaxel in patients with metastatic squamous cell carcinoma of the head and neck

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    This study was designed to evaluate the activity, safety and tolerance of docetaxel (D) in a selected population with metastatic squamous cell carcinoma of the head and neck (SCCHN). Twenty-four patients with no prior palliative therapy were enrolled and received D 100 mg m−2 by 1 h of infusion, every 3 weeks. All but two patients had been evaluated for efficacy on lung metastatic sites. No prophylactic administration of anti-emetics or growth factors was given. A pharmacokinetic study was performed in 22 patients. Twenty-one patients were assessable for response and 24 for toxicity. One hundred and four cycles were administered with a median of 4.5 (range 1–9) per patient. The median cumulative dose was 449 mg m−2. Partial responses were achieved in five patients with a median duration of 18.7 weeks (range 13.1–50.3). The overall response rate was 20.8% with a median duration of 11.0 weeks (range 2.4–52.6). The most frequent side-effect was neutropenia (79.2% grade IV) but with a short duration (median 4 days) and no febrile neutropenia. The incidence of moderate/severe fluid retention was 29.2% with one treatment discontinuation. Other toxicities (all grades) were common (skin 75%, asthenia 50%, infection 29.2%, nausea 16.7%, diarrhoea 12.5%, stomatitis 16.7%, vomiting 8.3% and HSR 8.3%). A mean clearance of 19.6 l h−1 m−2 and an area under the curve of 6.00 ÎŒg ml−1 h−1 was found in the pharmacokinetic analysis. Docetaxel is active in this selected population with metastatic SCCHN, with a good tolerance. © 1999 Cancer Research Campaig

    Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. VI. Variability of NGC 3783 from ground-based data

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    The Seyfert 1 galaxy NGC 3783 was intensely monitored between 1991 December and 1992 August. We present the results from the ground-based observations in the optical and near-IR, which complement the data-set from the IUE, discussed elsewhere. Spectroscopic and photometric data from many observatories were combined in order to obtain well sampled light curves of the continuum and of H-Beta. During the campaign the source varied significantly. The light curves of the optical continuum and of H-Beta are similar to those obtained with the IUE. The near-IR flux did not vary significantly except for an increase at the end of the campaign. The optical continuum and the flux of H-Beta lag the UV continuum by 1 day or less and by 8 days respectively. These results confirm that the continuum variations are simultaneous or have a very small lag across the entire UV-optical range, and that the lines of NGC 3783 respond to ionizing continuum variations with less delay than those of NGC 5548. As in NGC 5548, the lag of H-Beta is greater than those of the high ionization lines.Comment: 34 pages in LaTeX, 7 postscript figures available on request from [email protected] or 37907::stirpe, BAP#10-1993-035-OA

    Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 5: Variability of the ultraviolet continuum and emission lines of NGC 3783

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    We report on the results of intensive ultraviolet spectral monitoring of the Seyfert 1 galaxy NGC 3783. The nucleus of NGC 3783 was observed with the International Ultraviolet Explorer satellite on a regular basis for a total of 7 months, once every 4 days for the first 172 days and once every other day for the final 50 days. Significant variability was observed in both continuum and emission-line fluxes. The light curves for the continuum fluxes exhibited two well-defined local minima or 'dips,' the first lasting is less than or approximately 20 days and the second is less than or approximately 4 days, with additional episodes of relatively rapid flickering of approximately the same amplitude. As in the case of NGC 5548 (the only other Seyfert galaxy that has been the subject of such an intensive, sustained monitoring effort), the largest continuum variations were seen at the shortest wavelengths, so that the continuum became 'harder' when brighter. The variations in the continuum occurred simultaneously at all wavelengths (delta(t) is less than 2 days). Generally, the amplitude of variability of the emission lines was lower than (or comparable to) that of the continuum. Apart from Mg II (which varied little) and N V (which is relatively weak and badly blended with Ly(alpha), the light curves of the emission lines are very similar to the continuum light curves, in each case with a small systematic delay or 'lag.' As for NGC 5548, the highest ionization lines seem to respond with shorter lags than the lower ionization lines. The lags found for NGC 3783 are considerably shorter than those obtained for NGC 5548, with values of (formally) approximately 0 days for He II + O III), and approximately 4 days for Ly(alpha) and C IV. The data further suggest lags of approximately 4 days for Si IV + O IV) and 8-30 days for Si III + C III). Mg II lagged the 1460 A continuum by approximately 9 days, although this result depends on the method of measuring the line flux and may in fact be due to variability of the underlying Fe II lines. Correlation analysis further shows that the power density spectrum contains substantial unresolved power over timescales of is less than or approximately 2 days, and that the character of the continuum variability may change with time

    Multiwavelength observations of short time-scale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability

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    This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during the December 1993 monitoring campaign. The source, which was near its peak historical brightness, showed strong, correlated variability at X-ray, ultraviolet, and optical wavelengths. The strongest variations were seen in medium energy (∌\sim1.5~keV) X-rays, with a normalized variability amplitude (NVA) of 24\%. Weaker (NVA = 6\%) variations (uncorrelated with those at lower energies) were seen at soft Îł\gamma-ray energies of ∌\sim100~keV. No significant variability was seen in softer (0.1--1~keV) X-ray bands. In the ultraviolet/optical regime, the NVA decreased from 9\% to 1\% as the wavelength increased from 1275~\AA\ to 6900~\AA. These data do not probe extreme ultraviolet (1200~\AA\ to 0.1~keV) or hard X-ray (2--50~keV) variability. The phase differences between variations in different bands were consistent with zero lag, with upper limits of \ls0.15~day between 1275~\AA\ and the other ultraviolet bands, \ls0.3~day between 1275~\AA\ and 1.5~keV, and \ls1~day between 1275~\AA\ and 5125~\AA. These tight limits represent more than an order of magnitude improvement over those determined in previous multi-waveband AGN monitoring campaigns. The ultraviolet fluctuation power spectra showed no evidence for periodicity, but were instead well-fitted with a very steep, red power-law (a=−2.5 a = -2.5 ). If photons emitted at a ``primary" waveband are absorbed by nearby material and ``reprocessed" to produce emission at a secondary waveband, causality arguments require that variations in the secondary band follow those in the primary band. The tight interband correlation and limits on the ultraviolet andComment: 35 pages, LaTeX (including aaspp4), including 7 PostScript figures; To appear in the ApJ (October 20, 1996) Vol. 47

    Multiwavelength observations of short time-scale variability in NGC 4151. I. Ultraviolet observations

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    We present the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short time-scale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed continuously with the {\it International Ultraviolet Explorer} (IUE) for 9.3 days, yielding a pair of LWP and SWP spectra every ∌\sim70 minutes, and during four-hour periods for 4 days prior to and 5 days after the continuous monitoring period. The sampling frequency of the observations is an order of magnitude higher than that of any previous UV monitoring campaign on a Seyfert galaxy. The continuum fluxes in bands from 1275 \AA\ to 2688 \AA\ went through four significant and well-defined ``events'' of duration 2 -- 3 days during the continuous monitoring period. We find that the amplitudes of the continuum variations decrease with increasing wavelength, which extends a general trend for this and other Seyfert galaxies to smaller time scales (i.e., a few days). The continuum variations in all of the UV bands are {\it simultaneous} to within an accuracy of about 0.15 days, providing a strict constraint on continuum models. The emission-line light curves show only one major event during the continuous monitoring (a slow rise followed by a shallow dip), and do not correlate well with continuum light curves over the (short) duration of the campaign, because the time scale for continuum variations is apparently smaller than the response times of the emission lines.Comment: 39 pages, LaTeX, including 7 PostScript figures; To appear in the ApJ (October 20, 1996) Vol. 47

    High-quality health systems in the Sustainable Development Goals era: time for a revolution.

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    Executive summary: Although health outcomes have improved in low-income and middle-income countries (LMICs) in the past several decades, a new reality is at hand. Changing health needs, growing public expectations, and ambitious new health goals are raising the bar for health systems to produce better health outcomes and greater social value. But staying on current trajectory will not suffice to meet these demands. What is needed are high-quality health systems that optimise health care in each given context by consistently delivering care that improves or maintains health, by being valued and trusted by all people, and by responding to changing population needs. Quality should not be the purview of the elite or an aspiration for some distant future; it should be the DNA of all health systems. Furthermore, the human right to health is meaningless without good quality care because health systems cannot improve health without it. We propose that health systems be judged primarily on their impacts, including better health and its equitable distribution; on the confidence of people in their health system; and on their economic benefit, and processes of care, consisting of competent care and positive user experience. The foundations of high-quality health systems include the population and their health needs and expectations, governance of the health sector and partnerships across sectors, platforms for care delivery, workforce numbers and skills, and tools and resources, from medicines to data. In addition to strong foundations, health systems need to develop the capacity to measure and use data to learn. High-quality health systems should be informed by four values: they are for people, and they are equitable, resilient, and efficient. For this Commission, we examined the literature, analysed surveys, and did qualitative and quantitative research to evaluate the quality of care available to people in LMICs across a range of health needs included in the Sustainable Development Goals (SDGs). We explored the ethical dimensions of high-quality care in resource-constrained settings and reviewed available measures and improvement approaches. We reached five conclusions: The care that people receive is often inadequate, and poor-quality care is common across conditions and countries, with the most vulnerable populations faring the worst Data from a range of countries and conditions show systematic deficits in quality of care. In LMICs, mothers and children receive less than half of recommended clinical actions in a typical preventive or curative visit, less than half of suspected cases of tuberculosis are correctly managed, and fewer than one in ten people diagnosed with major depressive disorder receive minimally adequate treatment. Diagnoses are frequently incorrect for serious conditions, such as pneumonia, myocardial infarction, and newborn asphyxia. Care can be too slow for conditions that require timely action, reducing chances of survival. At the system level, we found major gaps in safety, prevention, integration, and continuity, reflected by poor patient retention and insufficient coordination across platforms of care. One in three people across LMICs cited negative experiences with their health system in the areas of attention, respect, communication, and length of visit (visits of 5 min are common); on the extreme end of these experiences were disrespectful treatment and abuse. Quality of care is worst for vulnerable groups, including the poor, the less educated, adolescents, those with stigmatised conditions, and those at the edges of health systems, such as people in prisons. Universal health coverage (UHC) can be a starting point for improving the quality of health systems. Improving quality should be a core component of UHC initiatives, alongside expanding coverage and financial protection. Governments should start by establishing a national quality guarantee for health services, specifying the level of competence and user experience that people can expect. To ensure that all people will benefit from improved services, expansion should prioritise the poor and their health needs from the start. Progress on UHC should be measured through effective (quality-corrected) coverage. High-quality health systems could save over 8 million lives each year in LMICs More than 8 million people per year in LMICs die from conditions that should be treatable by the health system. In 2015 alone, these deaths resulted in US$6 trillion in economic losses. Poor-quality care is now a bigger barrier to reducing mortality than insufficient access. 60% of deaths from conditions amenable to health care are due to poor-quality care, whereas the remaining deaths result from non-utilisation of the health system. High-quality health systems could prevent 2·5 million deaths from cardiovascular disease, 1 million newborn deaths, 900 000 deaths from tuberculosis, and half of all maternal deaths each year. Quality of care will become an even larger driver of population health as utilisation of health systems increases and as the burden of disease shifts to more complex conditions. The high mortality rates in LMICs for treatable causes, such as injuries and surgical conditions, maternal and newborn complications, cardiovascular disease, and vaccine preventable diseases, illustrate the breadth and depth of the health-care quality challenge. Poor-quality care can lead to other adverse outcomes, including unnecessary health-related suffering, persistent symptoms, loss of function, and a lack of trust and confidence in health systems. Waste of resources and catastrophic expenditures are economic side effects of poor-quality health systems. As a result of this, only one-quarter of people in LMICs believe that their health systems work well. Health systems should measure and report what matters most to people, such as competent care, user experience, health outcomes, and confidence in the system Measurement is key to accountability and improvement, but available measures do not capture many of the processes and outcomes that matter most to people. At the same time, data systems generate many metrics that produce inadequate insight at a substantial cost in funds and health workers' time. For example, although inputs such as medicines and equipment are commonly counted in surveys, these are weakly related to the quality of care that people receive. Indicators such as proportion of births with skilled attendants do not reflect quality of childbirth care and might lead to false complacency about progress in maternal and newborn health. This Commission calls for fewer, but better, measures of health system quality to be generated and used at national and subnational levels. Countries should report health system performance to the public annually by use of a dashboard of key metrics (eg, health outcomes, people's confidence in the system, system competence, and user experience) along with measures of financial protection and equity. Robust vital registries and trustworthy routine health information systems are prerequisites for good performance assessment. Countries need agile new surveys and real-time measures of health facilities and populations that reflect the health systems of today and not those of the past. To generate and interpret data, countries need to invest in national institutions and professionals with strong quantitative and analytical skills. Global development partners can support the generation and testing of public goods for health system measurement (civil and vital registries, routine data systems, and routine health system surveys) and promote national and regional institutions and the training and mentoring of scientists. New research is crucial for the transformation of low-quality health systems to high-quality ones Data on care quality in LMICs do not reflect the current disease burden. In many of these countries, we know little about quality of care for respiratory diseases, cancer, mental health, injuries, and surgery, as well as the care of adolescents and elderly people. There are vast blind spots in areas such as user experience, system competence, confidence in the system, and the wellbeing of people, including patient-reported outcomes. Measuring the quality of the health system as a whole and across the care continuum is essential, but not done. Filling in these gaps will require not only better routine health information systems for monitoring, but also new research, as proposed in the research agenda of this Commission. For example, research will be needed to rigorously evaluate the effects and costs of recommended improvement approaches on health, patient experience, and financial protection. Implementation science studies can help discern the contextual factors that promote or hinder reform. New data collection and research should be explicitly designed to build national and regional research capacity. Improving quality of care will require system-wide action To address the scale and range of quality deficits we documented in this Commission, reforming the foundations of the health system is required. Because health systems are complex adaptive systems that function at multiple interconnected levels, fixes at the micro-level (ie, health-care provider or clinic) alone are unlikely to alter the underlying performance of the whole system. However, we found that interventions aimed at changing provider behaviour dominate the improvement field, even though many of these interventions have a modest effect on provider performance and are difficult to scale and sustain over time. Achieving high-quality health systems requires expanding the space for improvement to structural reforms that act on the foundations of the system. This Commission endorses four universal actions to raise quality across the health system. First, health system leaders need to govern for quality by adopting a shared vision of quality care, a clear quality strategy, strong regulation, and continuous learning. Ministries of health cannot accomplish this alone and need to partner with the private sector, civil society, and sectors outside of health care, such as education, infrastructure, communication, and transport. Second, countries should redesign service delivery to maximise health outcomes rather than geographical access to services alone. Primary care could tackle a greater range of low-acuity conditions, whereas hospitals or specialised health centres should provide care for conditions, such as births, that need advanced clinical expertise or have the risk of unexpected complications. Third, countries should transform the health workforce by adopting competency-based clinical education, introducing training in ethics and respectful care, and better supporting and respecting all workers to deliver the best care possible. Fourth, governments and civil society should ignite demand for quality in the population to empower people to hold systems accountable and actively seek high-quality care. Additional targeted actions in areas such as health financing, management, district-level learning, and others can complement these efforts. What works in one setting might not work elsewhere, and improvement efforts should be adapted for local context and monitored. Funders should align their support with system-wide strategies rather than contribute to the proliferation of micro-level efforts. In this Commission, we assert that providing health services without guaranteeing a minimum level of quality is ineffective, wasteful, and unethical. Moving to a high-quality health system—one that improves health and generates confidence and economic benefits—is primarily a political, not technical, decision. National governments need to invest in high-quality health systems for their own people and make such systems accountable to people through legislation, education about rights, regulation, transparency, and greater public participation. Countries will know that they are on the way towards a high-quality, accountable health system when health workers and policymakers choose to receive health care in their own public institutions.Fil: Kruk, Margaret E.. Harvard University. Harvard School of Public Health; Estados UnidosFil: Gage, Anna D.. Harvard University. Harvard School of Public Health; Estados UnidosFil: Arsenault, Catherine. Harvard University. Harvard School of Public Health; Estados UnidosFil: Jordan, Keely. New York College of Global Public Health; Estados UnidosFil: Leslie, Hannah H.. Harvard University. Harvard School of Public Health; Estados UnidosFil: Roder DeWan, Sanam. Harvard University. Harvard School of Public Health; Estados UnidosFil: Adeyi, Olusoji. Banco Mundial; Estados UnidosFil: Barker, Pierre. Institute For Healthcare Improvement; Estados UnidosFil: Daelmans, Bernadette. Organizacion Mundial de la Salud; SuizaFil: Doubova, Svetlana V.. Instituto Mexicano del Seguro Social; MĂ©xicoFil: English, Mike. KEMRI - Wellcome Trust; KeniaFil: Garcia Elorrio, Ezequiel. Instituto de Efectividad ClĂ­nica y Sanitaria; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Guanais, Frederico. Banco Interamericano de Desarrollo; Estados UnidosFil: Gureje, Oye. University Of Ibadan; NigeriaFil: Hirschhorn, Lisa R.. Northwestern University; Estados UnidosFil: Jiang, Lixin. National Center For Cardiovascular Diseases; ChinaFil: Kelley, Edward. Organizacion Mundial de la Salud; SuizaFil: Lemango, Ephrem Tekle. Federal Ministry of Health; EtiopĂ­aFil: Liljestrand, Jerker. Bill and Melinda Gates Foundation; Estados UnidosFil: Malata, Address. Malawi University Of Science And Technology; MalauiFil: Marchant, Tanya. London School of Hygiene & Tropical Medicine; Reino UnidoFil: Matsoso, Malebona Precious. National Department of Health of the Republic of South Africa; SudĂĄfricaFil: Meara, John G.. Harvard Medical School; Estados UnidosFil: Mohanan, Manoj. University of Duke; Estados UnidosFil: Ndiaye, Youssoupha. Ministry of Health and Social Action of the Republic of Senegal; SenegalFil: Norheim, Ole F.. University of Bergen; NoruegaFil: Reddy, K. Srinath. Public Health Foundation of India; IndiaFil: Rowe, Alexander K.. Centers for Disease Control and Prevention; Estados UnidosFil: Salomon, Joshua A.. Stanford University School Of Medicine; Estados UnidosFil: Thapa, Gagan. Legislature Parliament Of Nepal; NepalFil: Twum Danso, Nana A. Y.. Maza; GhanaFil: Pate, Muhammad. Big Win Philanthropy; Reino Unid

    Empirically derived food patterns and the risk of total mortality and cardiovascular events in the predimed study

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    BACKGROUND & AIMS: There is little evidence on post hoc-derived dietary patterns (DP) and all-cause mortality in Southern-European populations. Furthermore, the potential effect modification of a DP by a nutritional intervention has not been sufficiently assessed. We assessed the association between a posteriori defined baseline major DP and total mortality or cardiovascular events within each of the three arms of a large primary prevention trial (PREDIMED) where participants were randomized to two active interventions with Mediterranean-type diets or to a control group (allocated to a low-fat diet). DESIGN: We followed-up 7216 participants for a median of 4.3 years. A validated 137-item food-frequency questionnaire was administered. Baseline DP were ascertained through factor analysis based on 34 predefined groups. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) for cardiovascular disease (CVD) or mortality across quartiles of DP within each of the three arms of the trial. RESULTS: We identified two major baseline DP: the first DP was rich in red and processed meats, alcohol, refined grains and whole dairy products and was labeled Western dietary pattern (WDP). The second DP corresponded to a "Mediterranean-type" dietary pattern (MDP). During follow-up, 328 participants died. After controlling for potential confounders, higher baseline adherence to the MDP was associated with lower risk of CVD (adjusted HR for fourth vs. first quartile: 0.52; 95% CI (Confidence Interval): 0.36, 0.74; p-trend <0.001) and all-cause mortality (adjusted HR: 0.53; 95% CI: 0.38, 0.75; p-trend <0.001), regardless of the allocated arm of the trial. An increasing mortality rate was found across increasing quartiles of the WDP in the control group (allocated to a low-fat diet), though the linear trend was not statistically significant (p = 0.098). CONCLUSIONS: Higher adherence to an empirically-derived MDP at baseline was associated with a reduced risk of CVD and mortality in the PREDIMED trial regardless of the allocated arm. The WDP was not associated with higher risk of mortality or cardiovascular events
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