1,721,202 research outputs found
Adaptative, multiple shooting optimization method for determining optimal spacecraft trajectories.
A new scope and a vision for record linkage studies
Record linkage - i.e. the use and linkage of electronic, mainly administrative databases - has been utilizedin epidemiologic research for over three decades now, starting from the system implemented in a fewUS health maintenance organizations (HMO, i.e. the Kaiser Permanente network), a few Nordic countriessystems, or the UK general practice research database (UK GPRD, now clinical practice research datalink,CPRD) [1, 2]...</p
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A meta-analysis of alcohol drinking and cancer risk
To evaluate the strength of the evidence provided by the epidemiological literature on the association between alcohol consumption and the risk of 18 neoplasms, we performed a search of the epidemiological literature from 1966 to 2000 using several bibliographic databases. Meta-regression models were fitted considering linear and non-linear effects of alcohol intake. The effects of characteristics of the studies, of selected covariates (tobacco) and of the gender of individuals included in the studies, were also investigated as putative sources of heterogeneity of the estimates. A total of 235 studies including over 117 000 cases were considered. Strong trends in risk were observed for cancers of the oral cavity and pharynx, oesophagus and larynx. Less strong direct relations were observed for cancers of the stomach, colon and rectum, liver, breast and ovary. For all these diseases, significant increased risks were found also for ethanol intake of 25 g per day. No significant nor consistent relation was observed for cancers of the pancreas, lung, prostate or bladder. Allowance for tobacco appreciably modified the relations with laryngeal, lung and bladder cancers, but not those with oral, oesophageal or colorectal cancers. This meta-analysis showed no evidence of a threshold effect for most alcohol-related neoplasms. The inference is limited by absence of distinction between lifelong abstainers and former drinkers in several studies, and the possible selective inclusion of relevant sites only in cohort studies
Are the recent trends in liver cirrhosis mortality affected by the changes in alcohol consumption? Analysis of latency period in European countries
Objective. A striking reduction of alcohol-related problems, such as liver cirrhosis death rates, has been observed in many western countries in recent years. It might be expected that these declines are accompanied by a lagged reduction in per capita alcohol consumption, since many years of intake are required for cirrhosis of the liver to develop (lag theory). The main aim of this study is to verify the validity of the lag theory, taking as target populations those resident in European countries. Method. Changes in liver cirrhosis death rates in 22 European countries between 1970 and 1989 were regressed onto changes in per capita alcohol consumption (1961-89) to evaluate the latency period between trends of these variables. Results: Eastern countries had a latency period between trends in alcohol consumption and in mortality rates of many years, whereas in northern, western and southern Europe cirrhosis mortality rates were explained by their relationship with per capita alcohol consumption, which lagged a few years. In some countries, an immediate contemporary appearance of the two phenomena was observed. Conclusions. These results suggest that the lag theory cannot fully explain the relationship between changing alcohol consumption and cirrhosis mortality and that other factors, such as alcoholism treatment rates, are involved in the wide geographical variability of the latency periods.
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Reaxys Database Information
Results of a retrospective database analysis of adherence to statin therapy and risk of nonfatal ischemic heart disease in daily clinical practice in Italy
BACKGROUND: Previous studies have reported that statin use was associated with reductions in cardiovascular morbidity and mortality among patients with dyslipidemia, even without established cardiovascular disease. However, inadequate adherence may reduce statins' protective effects. OBJECTIVE: The aim of this work was to investigate whether an association exists between statin adherence when used as primary prevention and risk of subsequent ischemic heart disease (IHD). METHODS: People aged >or=18 years who were residents of Italy's Lombardy region and were newly treated with statins in 2002 to 2003 were assessed as part of a retrospective analysis of data from a health services database. Patients who were hospitalized for IHD during this period were identified with hospital discharge information from a health-services database; IHD-related hospitalizations were identified by International Classification of Diseases, Ninth Revision, Clinical Modification, codes for acute myocardial infarction (410), acute and subacute forms of IHD (411), and/or codes concerning coronary revascularization (36.0-36.9). Four groups of patients were excluded: those with >or=1 lipid-lowering drug within 2 years before the index prescription (to limit the sample to treatment initiators); those who had been hospitalized for cardiovascular disease or had used medications for IHD or heart failure within 2 years before the index date (to limit the study to primary prevention); those who did not have >or=1 year of follow-up; and those who received only 1 dispensation of a statin during the first year after the index prescription. Follow-up continued until hospitalization for IHD or any other cardiovascular cause, death from any cause, emigration, or the end of the study period (June 30, 2007). The proportion of days covered (PDC) by therapy with statins was the exposure variable; it served as a proxy for adherence. PDC (and therefore adherence) was categorized as very low (or=75%) coverage. A proportional hazards model was fitted to estimate hazard ratio (HR) and 95% CIs for the association between time-dependent categories of PDC and time of IHD hospitalization, after correcting for covariates. RESULTS: A group of 90,832 patients was included; during follow-up, 1480 patients experienced a hospitalization for IHD. After the Cox proportional hazards model was adjusted for age, sex, type of statin dispensed at index prescription, current use of other selected drugs (ie, antidiabetics, antihypertensives, digitalis or organic nitrates, or other cardiac medications), Charlson comorbidity index, and whether or not a given patient switched statins, those with low, intermediate, or high statin coverage had HR (95% CI) values of 0.85 (0.72-0.98), 0.82 (0.71-0.95), and 0.81 (0.71-0.94), respectively, compared with patients with very low coverage. CONCLUSIONS: In these Italian subjects without a history of cardiovascular disease, low, intermediate, and high levels of adherence to statin pharmaco-therapy were associated with lower risk of nonfatal IHD compared with those who had very low (<or=25%) adherence. However, these findings have several limitations, such as the use of database information (rather than medical records), the assumption that PDC accurately represented actual adherence, and confounding (ie, unmeasured factors related to PDC or to adherence may have influenced clinical outcomes)
Variations on the Author
“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Long-term effect of high dose omega-3 fatty acid supplementation for secondary prevention of cardiovascular outcomes: A meta-analysis of randomized, placebo controlled trials
BACKGROUND:
Although omega-3 fatty acids have well documented properties which would reduce the cardiovascular (CV) disease risk, the evidence from randomized controlled trials (RCTs) remains inconclusive. We performed a meta-analysis of the available RCTs for investigating the CV preventive effect of administrating at least 1 gram/day, and for at least 1 year, omega-3 fatty acid supplements to patients with existing CV disease.
METHODS:
RCTs published up to March 2013 were searched from PubMed, EMBASE, and the Cochrane Library. Two of us independently reviewed and selected eligible trials.
RESULTS:
Of 360 articles retrieved, 11 randomized, double-blind, placebo controlled trials fulfilling inclusion criteria, overall involving 15,348 patients with a history of CV disease, were considered in the final analyses. No statistically significant association was observed for all-cause mortality (RR, 0.89; 95% CI, 0.78 to 1.02) and stroke (RR, 1.31; 95% CI, 0.90 to 1.90). Conversely, statistically significant protective effects were observed for cardiac death (RR, 0.68; 95% CI, 0.56 to 0.83), sudden death (RR, 0.67; 95% CI, 0.52 to 0.87), and myocardial infarction (RR, 0.75; 95% CI, 0.63 to 0.88).
CONCLUSION:
Overall, our results supply evidence that long-term effect of high dose omega-3 fatty acid supplementation may be beneficial for the onset of cardiac death, sudden death and myocardial infarction among patients with a history of cardiovascular disease
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