|
Meta-analyses
A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting measurements that are expected to have some degree of error. The aim then is to use approaches from statistics to derive a pooled estimate closest to the unknown common truth based on how this error is perceived. Meta-analytic results are considered the most trustworthy source of evidence by the evidence-based medicine literature.Herrera Ortiz AF., Cadavid Camacho E, Cubillos Rojas J, Cadavid Camacho T, Zoe Guevara S, Tatiana Rincón Cuenca N, Vásquez Perdomo A, Del Castillo Herazo V, & Giraldo Malo R. A Practical Guide to Perform a Systematic Literature Review and Meta-analysis. Principles and Practice of Clinical Research. 2022;7(4):47–57. https://doi.org/10.21801/ppcrj.2021.74.6 Not only can meta-analyses provide an estimate of the unk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Randomized Controlled Trial
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical techniques, medical devices, diagnostic procedures or other medical treatments. Participants who enroll in RCTs differ from one another in known and unknown ways that can influence study outcomes, and yet cannot be directly controlled. By Random assignment, randomly allocating participants among compared treatments, an RCT enables ''statistical control'' over these influences. Provided it is designed well, conducted properly, and enrolls enough participants, an RCT may achieve sufficient control over these confounding factors to deliver a useful comparison of the treatments studied. Definition and examples An RCT in clinical research typically compares a proposed new treatment against an existing Standard of care#Medical standard of care, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preferred Reporting Items For Systematic Reviews And Meta-Analyses
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) is an evidence-based minimum set of items aimed at helping scientific authors to report a wide array of systematic reviews and meta-analyses, primarily used to assess the benefits and harms of a health care intervention. PRISMA focuses on ways in which authors can ensure a transparent and complete reporting of this type of research. The PRISMA standard superseded the earlier QUOROM standard. It offers the replicability of a systematic literature review. Researchers have to figure out research objectives that answer the research question, states the keywords, a set of exclusion and inclusion criteria. In the review stage, relevant articles were searched, irrelevant ones are removed. Articles are analyzed according to some pre-defined categories. The PRISMA statement The aim of the PRISMA statement is to help authors improve the reporting of systematic reviews and meta-analyses. PRISMA has mainly focused on sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Study Heterogeneity
In statistics, (between-) study heterogeneity is a phenomenon that commonly occurs when attempting to undertake a meta-analysis. In a simplistic scenario, studies whose results are to be combined in the meta-analysis would all be undertaken in the same way and to the same experimental protocols. Differences between outcomes would only be due to measurement error (and studies would hence be ''Homogeneity (statistics), homogeneous''). Study heterogeneity denotes the variability (statistics), variability in outcomes that goes beyond what would be expected (or could be explained) due to measurement error alone. Introduction Meta-analysis is a method used to combine the results of different trials in order to obtain a quantitative synthesis. The size of individual clinical trials is often too small to detect treatment effects reliably. Meta-analysis increases the power of statistical analyses by pooling the results of all available trials. As one tries to use meta-analysis to estimate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Publication Bias
In published academic research, publication bias occurs when the outcome of an experiment or research study biases the decision to publish or otherwise distribute it. Publishing only results that show a significant finding disturbs the balance of findings in favor of positive results. The study of publication bias is an important topic in metascience. Despite similar quality of execution and design, papers with statistically significant results are three times more likely to be published than those with null results. This unduly motivates researchers to manipulate their practices to ensure statistically significant results, such as by data dredging. Many factors contribute to publication bias. For instance, once a scientific finding is well established, it may become newsworthy to publish reliable papers that fail to reject the null hypothesis. Most commonly, investigators simply decline to submit results, leading to non-response bias. Investigators may also assume they made a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Individual Participant Data
Individual participant data (also known as individual patient data, often abbreviated IPD) is raw data from individual participants, and is often used in the context of meta-analysis. The International Committee of Medical Journal Editors (ICMJE) has stated that sharing of deidentified individual participant data is an ethical obligation. IPD meta-analysis In an IPD meta-analysis, patient-level data from multiple studies or settings are combined to address a certain research question. IPD meta-analyses tend to be common for large-scale and international projects, and they are less limited than aggregate data (AD) meta-analyses in terms of the availability and quality of data they can use. Due to the high level of precision and consistency this approach allows for (which in turn makes it easier for researchers to minimize heterogeneity Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the uniformity of a substance or organism. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systematic Review
A systematic review is a Literature review, scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on the topic, then analyzes, describes, and summarizes interpretations into a refined conclusion. For example, a systematic review of randomized controlled trials is a way of summarizing and implementing evidence-based medicine. While a systematic review may be applied in the Biomedical research, biomedical or health care context, it may also be used where an assessment of a precisely defined subject can advance understanding in a field of research. A systematic review may examine clinical tests, public health interventions, environmental interventions, social interventions, adverse effects, qualitative evidence syntheses, methodological reviews, policy reviews, and economic evaluations. An understanding of systematic review ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effect Size
In statistics, an effect size is a value measuring the strength of the relationship between two variables in a population, or a sample-based estimate of that quantity. It can refer to the value of a statistic calculated from a sample of data, the value of a parameter for a hypothetical population, or to the equation that operationalizes how statistics or parameters lead to the effect size value. Examples of effect sizes include the correlation between two variables, the regression coefficient in a regression, the mean difference, or the risk of a particular event (such as a heart attack) happening. Effect sizes complement statistical hypothesis testing, and play an important role in power analyses, sample size planning, and in meta-analyses. The cluster of data-analysis methods concerning effect sizes is referred to as estimation statistics. Effect size is an essential component when evaluating the strength of a statistical claim, and it is the first item (magnitude) in the MAGI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cochrane Collaboration
Cochrane (previously known as the Cochrane Collaboration) is a British international charitable organisation formed to organise medical research findings to facilitate evidence-based choices about health interventions involving health professionals, patients and policy makers. It includes 53 review groups that are based at research institutions worldwide. Cochrane has approximately 30,000 volunteer experts from around the world. The group conducts systematic reviews of health-care interventions and diagnostic tests and publishes them in the Cochrane Library. According to the Library, articles are available via one-click access, but some require paid subscription or registration before reading. A few reviews, in occupational health for example, incorporate results from non-randomised observational studies as well as controlled before–after (CBA) studies and interrupted time-series studies. History Cochrane, previously known as the Cochrane Collaboration, was founded in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meta-regression
Meta-regression is defined to be a meta-analysis that uses regression analysis to combine, compare, and synthesize research findings from multiple studies while adjusting for the effects of available covariates on a response variable. A meta-regression analysis aims to reconcile conflicting studies or corroborate consistent ones; a meta-regression analysis is therefore characterized by the collated studies and their corresponding data sets—whether the response variable is study-level (or equivalently ''aggregate'') data or individual participant data (or individual patient data in medicine). A data set is ''aggregate'' when it consists of summary statistics such as the sample mean, effect size, or odds ratio. On the other hand, individual participant data are in a sense ''raw'' in that all observations are reported with no abridgment and therefore no information loss. Aggregate data are easily compiled through internet search engines and therefore not expensive. However, individu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evidence-based Medicine
Evidence-based medicine (EBM) is "the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients". The aim of EBM is to integrate the experience of the clinician, the values of the patient, and the best available scientific information to guide decision-making about clinical management. The term was originally used to describe an approach to teaching the practice of medicine and improving decisions by individual physicians about individual patients. Background, history and definition Medicine has a long history of scientific inquiry about the prevention, diagnosis, and treatment of human disease. The concept of a controlled clinical trial was first described in 1662 by Jan Baptist van Helmont in reference to the practice of bloodletting. Wrote Van Helmont: The first published report describing the conduct and results of a controlled clinical trial was by James Lind, a Scottish naval surgeon who conducted rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larry V
Larry is a masculine given name in English, derived from Lawrence or Laurence. It can be a shortened form of those names. Larry may refer to the following: People Arts and entertainment * Larry D. Alexander, American artist/writer *Larry Boone, American country singer * Larry Collins, American musician, member of the rockabilly sibling duo The Collins Kids *Larry David (born 1947), Emmy-winning American actor, writer, comedian, producer and film director *Larry Emdur, Australian TV host *Larry Feign, American cartoonist working in Hong Kong *Larry Fine, of the Three Stooges *Larry Gates, American actor *Larry Gatlin, American country singer *Larry Gelbart (1928–2009), American screenwriter, playwright, director and author *Larry Graham, founder of American funk band Graham Central Station *Larry Hagman, American actor, best known for the TV series ''I Dream of Jeannie'' and ''Dallas'' *Larry Henley (1937–2014), American singer and songwriter, member of The Newbeats *Larry Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jessica Gurevitch
Jessica Gurevitch is plant ecologist known for meta-analysis in the fields of ecology and evolution. Education and career Gurevitch has a B.S. from Cornell University (1973) and earned her Ph.D. in ecology and evolutionary biology from the University of Arizona in 1982. She was a postdoctoral fellow for two years at the University of Chicago before moving to the State University of New York at Stony Brook in 1985. For two years starting in 1992, Guervitch worked at the National Science Foundation before returning to Stony Brook where she was promoted to professor in 2000. From 2015 to 2016, Gurevitch was president of the Society for Research Synthesis Methodology. Research Gurevitch's research interests are centered on biological invasions and meta-analysis in ecology. Her research on grasses perennial plants, and trees relied on a combination of experimental manipulations and observation data. Her interest in biological invasions includes investigations into the invasive flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
