60 resultados para observational methods

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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In the discussion about the rationale for spine registries, two basic questions have to be answered. The first one deals with the value of orthopaedic registries per se, considering them as observational studies and comparing the evidence they generate with that of randomised controlled trials. The second question asks if the need for registries in spine surgery is similar to that in the arthroplasty sector. The widely held view that randomised controlled trials are the 'gold standard' for evaluation and that observational methods have little or no value ignores the limitations of randomised trials. They may prove unnecessary, inappropriate, impossible, or inadequate. In addition, the external validity and hence the ability to make generalisations about the results of randomised trials is often low. Therefore, the false conflict between those who advocate randomised trials in all situations and those who believe observational data provide sufficient evidence needs to be replaced with mutual recognition of their complementary roles. The fact that many surgical techniques or technologies were introduced into the field of spine surgery without randomised trials or prospective cohort comparisons makes obvious an even increased need for spine registries compared to joint arthroplasty. An essential methodological prerequisite for a registry is a common terminology for reporting results and a sophisticated technology that networks all participants so that one central data pool is created and accessed. Recognising this need, the Spine Society of Europe has researched and developed Spine Tango, the first European spine registry, which can be accessed under www.eurospine.org.

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The global ocean is a significant sink for anthropogenic carbon (Cant), absorbing roughly a third of human CO2 emitted over the industrial period. Robust estimates of the magnitude and variability of the storage and distribution of Cant in the ocean are therefore important for understanding the human impact on climate. In this synthesis we review observational and model-based estimates of the storage and transport of Cant in the ocean. We pay particular attention to the uncertainties and potential biases inherent in different inference schemes. On a global scale, three data-based estimates of the distribution and inventory of Cant are now available. While the inventories are found to agree within their uncertainty, there are considerable differences in the spatial distribution. We also present a review of the progress made in the application of inverse and data assimilation techniques which combine ocean interior estimates of Cant with numerical ocean circulation models. Such methods are especially useful for estimating the air–sea flux and interior transport of Cant, quantities that are otherwise difficult to observe directly. However, the results are found to be highly dependent on modeled circulation, with the spread due to different ocean models at least as large as that from the different observational methods used to estimate Cant. Our review also highlights the importance of repeat measurements of hydrographic and biogeochemical parameters to estimate the storage of Cant on decadal timescales in the presence of the variability in circulation that is neglected by other approaches. Data-based Cant estimates provide important constraints on forward ocean models, which exhibit both broad similarities and regional errors relative to the observational fields. A compilation of inventories of Cant gives us a "best" estimate of the global ocean inventory of anthropogenic carbon in 2010 of 155 ± 31 PgC (±20% uncertainty). This estimate includes a broad range of values, suggesting that a combination of approaches is necessary in order to achieve a robust quantification of the ocean sink of anthropogenic CO2.

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Background: Annual syphilis testing was reintroduced in the Swiss HIV Cohort Study (SHCS) in 2004. We prospectively studied occurrence, risk factors, clinical manifestations, diagnostic approaches and treatment of syphilis. Methods: Over a period of 33 months, participants with positive test results for Treponema pallidum hemagglutination assay were studied using the SHCS database and an additional structured case report form. Results: Of 7244 cohort participants, 909 (12.5%) had positive syphilis serology. Among these, 633 had previously been treated and had no current signs or symptoms of syphilis at time of testing. Of 218 patients with newly detected untreated syphilis, 20% reported genitooral contacts as only risk behavior and 60% were asymptomatic. Newly detected syphilis was more frequent among men who have sex with men (MSM) [adjusted odds ratio (OR) 2.8, P < 0.001], in persons reporting casual sexual partners (adjusted OR 2.8, P < 0.001) and in MSM of younger age (P = 0.05). Only 35% of recommended cerebrospinal fluid (CFS) examinations were performed. Neurosyphilis was diagnosed in four neurologically asymptomatic patients; all of them had a Venereal Disease Research Laboratory (VDRL) titer of 1:≥32. Ninety-one percent of the patients responded to treatment with at least a four-fold decline in VDRL titer. Conclusion: Syphilis remains an important coinfection in the SHCS justifying reintroduction of routine screening. Genitooral contact is a significant way of transmission and young MSM are at high risk for syphilis. Current guidelines to rule out neurosyphilis by CSF analysis are inconsistently followed in clinical practice. Serologic treatment response is above 90% in the era of combination antiretroviral therapy.

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PURPOSE: To determine the incidence of and risk factors for adverse cardiac events during catecholamine vasopressor therapy in surgical intensive care unit patients with cardiovascular failure. METHODS: The occurrence of any of seven predefined adverse cardiac events (prolonged elevated heart rate, tachyarrhythmia, myocardial cell damage, acute cardiac arrest or death, pulmonary hypertension-induced right heart dysfunction, reduction of systemic blood flow) was prospectively recorded during catecholamine vasopressor therapy lasting at least 12 h. RESULTS: Fifty-four of 112 study patients developed a total of 114 adverse cardiac events, an incidence of 48.2 % (95 % CI, 38.8-57.6 %). New-onset tachyarrhythmia (49.1 %), prolonged elevated heart rate (23.7 %), and myocardial cell damage (17.5 %) occurred most frequently. Aside from chronic liver diseases, factors independently associated with the occurrence of adverse cardiac events included need for renal replacement therapy, disease severity (assessed by the Simplified Acute Physiology Score II), number of catecholamine vasopressors (OR, 1.73; 95 % CI, 1.08-2.77; p = 0.02) and duration of catecholamine vasopressor therapy (OR, 1.01; 95 % CI, 1-1.01; p = 0.002). Patients developing adverse cardiac events were on catecholamine vasopressors (p < 0.001) and mechanical ventilation (p < 0.001) for longer and had longer intensive care unit stays (p < 0.001) and greater mortality (25.9 vs. 1.7 %; p < 0.001) than patients who did not. CONCLUSIONS: Adverse cardiac events occurred in 48.2 % of surgical intensive care unit patients with cardiovascular failure and were related to morbidity and mortality. The extent and duration of catecholamine vasopressor therapy were independently associated with and may contribute to the pathogenesis of adverse cardiac events.

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Background During acute coronary syndromes patients perceive intense distress. We hypothesized that retrospective ratings of patients' MI-related fear of dying, helplessness, or pain, all assessed within the first year post-MI, are associated with poor cardiovascular outcome. Methods We studied 304 patients (61 ± 11 years, 85% men) who after a median of 52 days (range 12-365 days) after index MI retrospectively rated the level of distress in the form of fear of dying, helplessness, or pain they had perceived at the time of MI on a numeric scale ranging from 0 ("no distress") to 10 ("extreme distress"). Non-fatal hospital readmissions due to cardiovascular disease (CVD) related events (i.e., recurrent MI, elective and non-elective stent implantation, bypass surgery, pacemaker implantation, cerebrovascular incidents) were assessed at follow-up. The relative CVD event risk was computed for a (clinically meaningful) 2-point increase of distress using Cox proportional hazard models. Results During a median follow-up of 32 months (range 16-45), 45 patients (14.8%) experienced a CVD-related event requiring hospital readmission. Greater fear of dying (HR 1.21, 95% CI 1.03-1.43), helplessness (HR 1.22, 95% CI 1.04-1.44), or pain (HR 1.27, 95% CI 1.02-1.58) were significantly associated with an increased CVD risk without adjustment for covariates. A similarly increased relative risk emerged in patients with an unscheduled CVD-related hospital readmission, i.e., when excluding patients with elective stenting (fear of dying: HR 1.26, 95% CI 1.05-1.51; helplessness: 1.26, 95% CI 1.05-1.52; pain: HR 1.30, 95% CI 1.01-1.66). In the fully-adjusted models controlling for age, the number of diseased coronary vessels, hypertension, and smoking, HRs were 1.24 (95% CI 1.04-1.46) for fear of dying, 1.26 (95% CI 1.06-1.50) for helplessness, and 1.26 (95% CI 1.01-1.57) for pain. Conclusions Retrospectively perceived MI-related distress in the form of fear of dying, helplessness, or pain was associated with non-fatal cardiovascular outcome independent of other important prognostic factors.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change, susceptibility, and clinical outcomes are used as proxies for investigating the interactions between external and/or endogenous agents and the body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as STrengthening Reporting of Observational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology-Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE Statement implementing 9 existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change susceptibility and clinical outcomes are used as proxies for investigating the interactions between external and/or endogenous agents and body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as the STrengthening Reporting of OBservational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology -Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE statement implementing 9 existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change, susceptibility and clinical outcomes are used as proxies for investigating the interactions between external and/or endogenous agents and the body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as the STrenghtening Reporting of Observational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology - Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE Statement implementing 9 existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change, susceptibility and clinical outcomes are used as proxies for investigating interactions between external and / or endogenous agents and body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as the STrengthening Reporting of OBservational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology - Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE statement implementing nine existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change, susceptibility and clinical outcomes are used as proxies for investigating interactions between external and/or endogenous agents and body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as the STrengthening Reporting of OBservational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology -Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE statement implementing nine existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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Advances in laboratory techniques have led to a rapidly increasing use of biomarkers in epidemiological studies. Biomarkers of internal dose, early biological change, susceptibility, and clinical outcomes are used as proxies for investigating the interactions between external and/or endogenous agents and the body components or processes. The need for improved reporting of scientific research led to influential statements of recommendations such as STrengthening Reporting of Observational studies in Epidemiology (STROBE) statement. The STROBE initiative established in 2004 aimed to provide guidance on how to report observational research. Its guidelines provide a user-friendly checklist of 22 items to be reported in epidemiological studies, with items specific to the three main study designs: cohort studies, case-control studies and cross-sectional studies. The present STrengthening the Reporting of OBservational studies in Epidemiology - Molecular Epidemiology (STROBE-ME) initiative builds on the STROBE Statement implementing 9 existing items of STROBE and providing 17 additional items to the 22 items of STROBE checklist. The additions relate to the use of biomarkers in epidemiological studies, concerning collection, handling and storage of biological samples; laboratory methods, validity and reliability of biomarkers; specificities of study design; and ethical considerations. The STROBE-ME recommendations are intended to complement the STROBE recommendations.

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OBJECTIVE: To compare regimens consisting of either efavirenz or nevirapine and two or more nucleoside reverse transcriptase inhibitors (NRTIs) among HIV-infected, antiretroviral-naive, and AIDS-free individuals with respect to clinical, immunologic, and virologic outcomes. DESIGN: Prospective studies of HIV-infected individuals in Europe and the US included in the HIV-CAUSAL Collaboration. METHODS: Antiretroviral therapy-naive and AIDS-free individuals were followed from the time they started an NRTI, efavirenz or nevirapine, classified as following one or both types of regimens at baseline, and censored when they started an ineligible drug or at 6 months if their regimen was not yet complete. We estimated the 'intention-to-treat' effect for nevirapine versus efavirenz regimens on clinical, immunologic, and virologic outcomes. Our models included baseline covariates and adjusted for potential bias introduced by censoring via inverse probability weighting. RESULTS: A total of 15 336 individuals initiated an efavirenz regimen (274 deaths, 774 AIDS-defining illnesses) and 8129 individuals initiated a nevirapine regimen (203 deaths, 441 AIDS-defining illnesses). The intention-to-treat hazard ratios [95% confidence interval (CI)] for nevirapine versus efavirenz regimens were 1.59 (1.27, 1.98) for death and 1.28 (1.09, 1.50) for AIDS-defining illness. Individuals on nevirapine regimens experienced a smaller 12-month increase in CD4 cell count by 11.49 cells/mul and were 52% more likely to have virologic failure at 12 months as those on efavirenz regimens. CONCLUSIONS: Our intention-to-treat estimates are consistent with a lower mortality, a lower incidence of AIDS-defining illness, a larger 12-month increase in CD4 cell count, and a smaller risk of virologic failure at 12 months for efavirenz compared with nevirapine.

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BACKGROUND: The study is part of a nationwide evaluation of complementary and alternative medicine (CAM) in primary care in Switzerland. OBJECTIVES: Patient health status with respect to demographic attributes such as gender, age, and health care utilisation pattern was studied and compared with conventional primary care. METHODS: The study was performed as a cross-sectional survey including 11932 adult patients seeking complementary or conventional primary care. Patients were asked to document their self-perceived health status by completing a questionnaire in the waiting room. Physicians were performing conventional medicine and/or various forms of complementary primary care such as homeopathy, anthroposophic medicine, neural therapy, herbal medicine, or traditional Chinese medicine. Additional information on patient demographics and yearly consultation rates for participating physicians was obtained from the data pool of all Swiss health insurers. These data were used to confirm the survey results. RESULTS: We observed considerable and significant differences in demographic attributes of patients seeking complementary and conventional care. Patients seeking complementary care documented longer lasting and more severe main health problems than patients in conventional care. The number of previous physician visits differed between patient groups, which indicates higher consumption of medical resources by CAM patients. CONCLUSIONS: The study supports the hypothesis of differences in socio-demographic and behavioural attributes of patients seeking conventional medicine or CAM in primary care. The study provides empirical evidence that CAM users are requiring more physician-based medical services in primary care than users of conventional medicine.

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Much biomedical research is observational. The reporting of such research is often inadequate, which hampers the assessment of its strengths and weaknesses and of a study's generalisability. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative developed recommendations on what should be included in an accurate and complete report of an observational study. We defined the scope of the recommendations to cover three main study designs: cohort, case-control, and cross-sectional studies. We convened a 2-day workshop in September, 2004, with methodologists, researchers, and journal editors to draft a checklist of items. This list was subsequently revised during several meetings of the coordinating group and in e-mail discussions with the larger group of STROBE contributors, taking into account empirical evidence and methodological considerations. The workshop and the subsequent iterative process of consultation and revision resulted in a checklist of 22 items (the STROBE statement) that relate to the title, abstract, introduction, methods, results, and discussion sections of articles.18 items are common to all three study designs and four are specific for cohort, case-control, or cross-sectional studies.A detailed explanation and elaboration document is published separately and is freely available on the websites of PLoS Medicine, Annals of Internal Medicine, and Epidemiology. We hope that the STROBE statement will contribute to improving the quality of reporting of observational studies

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Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalizability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies.The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers.This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated web site (http://www.strobe-statement.org) should be helpful resources to improve reporting of observational research.