Julian P.T. Higgins | |
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Born | Julian Piers Thomas Higgins |
Nationality | British |
Education | Durham University, University of Cambridge, and The University of Reading |
Known for | Meta-analysis |
Awards | Cochrane Collaboration's Thomas C. Chalmers Award; Society for Research Synthesis Methodology's Ingram Olkin Award for distinguished lifetime achievement in research synthesis methodology; the Campbell Collaboration's Frederick Mosteller Award for Distinctive Contributions to Systematic Reviewing |
Scientific career | |
Fields | Biostatistics |
Institutions | Imperial College London University College London University of York Medical Research Council University of Bristol |
Thesis | Exploiting information in random effects meta-analysis (1997) |
Julian P. T. Higgins is a British biostatistician, Professor of Evidence Synthesis and Director of Research at the Department of Population Health Sciences at the University of Bristol. [1] Higgins was previously Chair in Evidence Synthesis at the University of York, and Programme Leader at the MRC Biostatistics Unit in Cambridge. He is also a founding trustee and a Past-President of the Society for Research Synthesis Methodology. [2]
Higgins was born in North Yorkshire, where he attended the Stokesley School. He completed his undergraduate studies in mathematics at Durham University in 1992, earned a diploma in mathematical statistics from the University of Cambridge in 1993, and obtained a PhD in applied statistics from the University of Reading in 1997. [3]
Higgins is a Senior Investigator at the National Institute for Health Research (NIHR). An expert on meta-analysis and systematic review methodologies, Professor Higgins contributes actively to the Cochrane Collaboration, where he also serves as Senior Methods Advisor. He is a co-editor of the Cochrane Handbook for Systematic Reviews of Interventions and has been named an ISI Highly Cited researcher each year since 2015. [4]
On 28 August 2019 Higgins, along with Jonathan Sterne, Jelena Savović, and colleagues, published in The British Medical Journal an article detailing "RoB 2", a revised tool for assessing risk of bias in randomized trials. [5] Assessing risk of bias is regarded as an essential component of a systematic review. The most commonly used tool for assessing risk of bias to date has been the Cochrane risk-of-bias tool, which Professor Higgins introduced in 2008. [6] Higgins is the most cited author of The British Medical Journal. [7]
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.
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. It is thus a basic methodology of Metascience. Meta-analytic results are considered the most trustworthy source of evidence by the evidence-based medicine literature.
A randomized controlled trial 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.
The Cochrane Collaboration is a British international charitable organisation formed to synthesise 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 Cochrane Library is a collection of databases in medicine and other healthcare specialties provided by Cochrane and other organizations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses which summarize and interpret the results of medical research. The Cochrane Library aims to make the results of well-conducted controlled trials readily available and is a key resource in evidence-based medicine.
A systematic review is a 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, critically appraises and summarizes interpretations into a refined evidence-based conclusion. For example, a systematic review of randomized controlled trials is a way of summarizing and implementing evidence-based medicine.
Yoga as therapy is the use of yoga as exercise, consisting mainly of postures called asanas, as a gentle form of exercise and relaxation applied specifically with the intention of improving health. This form of yoga is widely practised in classes, and may involve meditation, imagery, breath work (pranayama) and calming music as well as postural yoga.
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. Study heterogeneity denotes the variability in outcomes that goes beyond what would be expected due to measurement error alone.
In epidemiology, reporting bias is defined as "selective revealing or suppression of information" by subjects. In artificial intelligence research, the term reporting bias is used to refer to people's tendency to under-report all the information available.
A funnel plot is a graph designed to check for the existence of publication bias; funnel plots are commonly used in systematic reviews and meta-analyses. In the absence of publication bias, it assumes that studies with high precision will be plotted near the average, and studies with low precision will be spread evenly on both sides of the average, creating a roughly funnel-shaped distribution. Deviation from this shape can indicate publication bias.
The Jadad scale, sometimes known as Jadad scoring or the Oxford quality scoring system, is a procedure to assess the methodological quality of a clinical trial by objective criteria. It is named after Canadian-Colombian physician Alex Jadad who in 1996 described a system for allocating such trials a score of between zero and five (rigorous). It is the most widely used such assessment in the world, and as of 2022, its seminal paper has been cited in over 23,000 scientific works.
Critical appraisal in evidence based medicine, is the use of explicit, transparent methods to assess the data in published research, applying the rules of evidence to factors such as internal validity, adherence to reporting standards, conclusions, generalizability and risk-of-bias. Critical appraisal methods form a central part of the systematic review process. They are used in evidence synthesis to assist clinical decision-making, and are increasingly used in evidence-based social care and education provision.
PRISMA 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.
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 data or individual participant data. 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, individual participant data are usually confidential and are only accessible within the group or organization that performed the studies.
The discipline of evidence-based toxicology (EBT) strives to transparently, consistently, and objectively assess available scientific evidence in order to answer questions in toxicology, the study of the adverse effects of chemical, physical, or biological agents on living organisms and the environment, including the prevention and amelioration of such effects. EBT has the potential to address concerns in the toxicological community about the limitations of current approaches to assessing the state of the science. These include concerns related to transparency in decision making, synthesis of different types of evidence, and the assessment of bias and credibility. Evidence-based toxicology has its roots in the larger movement towards evidence-based practices.
The United States Cochrane Center (USCC) was one of the 14 centers on the world that facilitated the work of the Cochrane Collaboration. The USCC was the reference center for all 50 US states and US territories, protectorates, and districts: the District of Columbia, American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the US Virgin Islands. The USCC was also the reference Center for the following countries: Antigua and Barbuda, Bahamas, Barbados, Belize, Dominica, Grenada, Guam, Guyana, Jamaica, Japan, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, and Trinidad and Tobago. The USCC discontinued on February 7, 2018.
Lesley Ann Stewart is a Scottish academic whose research interests are in the development and application of evidence synthesis methods, particularly systematic reviews and individual participant data meta-analysis. She is head of department for the Centre for Reviews and Dissemination at the University of York and director for the NIHR Evidence Synthesis Programme. She was one of the founders of the Cochrane Collaboration in 1993. Stewart served as president of the Society for Research Synthesis Methodology (2013-2016) and was a founding co-editor in chief of the academic journal Systematic Reviews (2010–2021).
Isabelle Boutron is a professor of epidemiology at the Université Paris Cité and head of the INSERM- METHODS team within the Centre of Research in Epidemiology and Statistics (CRESS). She was originally trained in rheumatology and later switched to a career in epidemiology and public health. She is also deputy director of the French EQUATOR Centre, member of the SPIRIT-CONSORT executive committee, director of Cochrane France and co-convenor of the Bias Methods group of the Cochrane Collaboration.
Kay Dickersin is an academic who trained first in cell biology and subsequently epidemiology. She went on to a career studying factors that influence research integrity, in particular publication bias and outcome reporting bias. She is retired Professor Emerita in the Department of Epidemiology at Johns Hopkins Bloomberg School of Public Health where she was Director of the Center for Clinical Trials and Evidence Synthesis there. She was also Director of the US Cochrane Center and the US Satellite of the Cochrane Eyes and Vision Group within the Cochrane Collaboration. Dickersin received multiple awards for her research.
Jonathan A.C. Sterne is a British statistician, NIHR Senior Investigator, Professor of Medical Statistics and Epidemiology, and the former Head of School of Social and Community Medicine at the University of Bristol. He is co-author of “Essential Medical Statistics”, which received Highly Commended honors in the 2004 BMA Medical Book Competition.