Search results for "Study Design"
showing 10 items of 51 documents
Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences
2020
Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental da…
Improving scientific rigour in conservation evaluations and a plea deal for transparency on potential biases
2020
Abstract The delivery of rigorous and unbiased evidence on the effects of interventions lay at the heart of the scientific method. Here we examine scientific papers evaluating agri‐environment schemes, the principal instrument to mitigate farmland biodiversity declines worldwide. Despite previous warnings about rudimentary study designs in this field, we found that the majority of studies published between 2008 and 2017 still lack robust study designs to strictly evaluate intervention effects. Potential sources of bias that arise from the correlative nature are rarely mentioned, and results are still promoted by using a causal language. This lack of robust study designs likely results from …
Fruit body based inventories in wood-inhabiting fungi: Should we replicate in space or time?
2016
We assessed the effect of survey design on the results when conducting fruit body surveys of wood-inhabiting fungi. Our results demonstrate that the optimal design depends on the ecological question to be addressed, as well as the group of fungal species under research. If the aim is to record the total species richness in a dead wood unit or to estimate the population size of a species, repeating the survey over time is generally necessary. However, if the aim is to estimate the total species richness in the forest or to assess how environmental covariates influence species richness or community composition, it is generally more efficient to increase the number of dead wood units than to r…
Perspective: Essential study quality descriptors for data from nutritional epidemiologic research
2017
Pooled analysis of secondary data increases the power of research and enables scientific discovery in nutritional epidemiology. Information on study characteristics that determine data quality is needed to enable correct reuse and interpretation of data. This study aims to define essential quality characteristics for data from observational studies in nutrition. First, a literature review was performed to get an insight on existing instruments that assess the quality of cohort, case-control, and cross-sectional studies and dietary measurement. Second, 2 face-to-face workshops were organized to determine the study characteristics that affect data quality. Third, consensus on the data descrip…
Standardising clinical outcomes measures for adult clinical trials in Fabry disease: A global Delphi consensus.
2021
International audience; Background: Recent years have witnessed a considerable increase in clinical trials of new investigational agents for Fabry disease (FD). Several trials investigating different agents are currently in progress; however, lack of standardisation results in challenges to interpretation and comparison. To facilitate the standardisation of investigational programs, we have developed a common framework for future clinical trials in FD.Methods and findings: A broad consensus regarding clinical outcomes and ways to measure them was obtained via the Delphi methodology. 35 FD clinical experts from 4 continents, representing 3389 FD patients, participated in 3 rounds of Delphi p…
Young Adult and Usual Adult Body Mass Index and Multiple Myeloma Risk: A Pooled Analysis in the International Multiple Myeloma Consortium (IMMC)
2017
AbstractBackground: Multiple myeloma risk increases with higher adult body mass index (BMI). Emerging evidence also supports an association of young adult BMI with multiple myeloma. We undertook a pooled analysis of eight case–control studies to further evaluate anthropometric multiple myeloma risk factors, including young adult BMI.Methods: We conducted multivariable logistic regression analysis of usual adult anthropometric measures of 2,318 multiple myeloma cases and 9,609 controls, and of young adult BMI (age 25 or 30 years) for 1,164 cases and 3,629 controls.Results: In the pooled sample, multiple myeloma risk was positively associated with usual adult BMI; risk increased 9% per 5-kg/m…
The dietary inflammatory index and human health: an umbrella review of meta-analyses of observational studies
2021
Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: Statistical heterog…
The person-oriented approach to burnout : A systematic review
2016
The variable-oriented approach has dominated empirical burnout research, but during the last 10 years a person-oriented approach to burnout has also become common. The aim of this systematic literature review was to identify, categorize and evaluate the empirical research to date that has adopted a person-oriented approach to burnout. The results of these studies were then compared with those generated by variable-oriented burnout research. An electronic search of seven databases was conducted in spring 2015. Initially 470 publications were identified, 24 of which met the selection criteria. The reviewed articles were categorized into three groups based on their research target(s): (1) intr…
Evaluation of Risk Stratification Markers and Models in Acute Pulmonary Embolism: Rationale and Design of the MARS-PE (Mainz Retrospective Study of P…
2018
An acute pulmonary embolism (PE) is a crucial event in patients’ life and connected with serious morbidity and mortality. Regarding a high case-fatality rate, early and accurate risk-stratification is crucial. Risk for mortality and complications are closely related to hemodynamic stability and cardiac adaptations. The currently recommended risk-stratification approach is not overall simple to use and might delay the identification of those patients, who should be monitored more closely and may treated with more aggressive treatment strategies. Additionally, some risk-stratification criteria for the imaging procedures are still imprecise. Summarized, the search for the most effective risk-s…
Validity of a questionnaire developed to measure the impact of a high‐fidelity simulation intervention: A feasibility study
2019
To evaluate the validity and responsiveness of a questionnaire developed to measure the impact of a high-fidelity simulation intervention.A pre- and postintervention design.In August 2017, 107 participants completed a questionnaire measuring knowledge and perceived self-confidence pre- and postintervention. Validity of the questionnaire was determined by expert reviews, individual interviews and estimates of the changes in knowledge and perceived self-confidence. The changes were estimated by the differences between paired proportions of participants. The responsiveness of the ordered categorical item scores on self-confidence was evaluated by the measure of systematic group change and indi…