John P A Ioannidis
Biographic Data
| ID | 919023 |
|---|---|
| NAME | John P A Ioannidis |
| GIVEN NAMES | John P A |
| FAMILY NAME | Ioannidis |
| SIGNATURE | IOANNIDIS J P A |
| AFFILIATIONS | Stanford University |
| ORCID | 0000-0003-3118-6859 |
| VERIFIED | Yes |
| TOTAL WORKS | 50 |
| TOTAL CITATIONS | 264 |
| AUTHOR COUNT | 50 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1999 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 4 |
Instability of Global Burden of Disease Estimates of Deaths and Disability-Adjusted Life-Years From Major Risk Factors
This meta-epidemiological assessment indicates that GBD estimates are substantially unstable, particularly for behavioral risks, making them unlikely to simply reflect genuine changes over time, and warranting caution in interpretation
Provenance and Funding of Extremely Cited Biomedical Articles Published Between 2003 and 2024
Results of this study suggest that, overall, the US remains a world leader regarding the most highly cited biomedical research and NIH funding retains a substantial presence among top-cited articles. However, NIH influence had decreased overall, and top-cited articles funded exclusively by NIH have almost disappeared. Strengthening public funding is essential to secure research that serves the common good
Global Estimates of Lives and Life-Years Saved by Covid-19 Vaccination During 2020-2024
Estimates in this study are substantially more conservative than previous calculations focusing mostly on the first year of vaccination, but they still clearly demonstrate a major overall benefit from COVID-19 vaccination during the years 2020-2024. Most benefits in lives and life-years saved was secured for a portion of older persons, a minority of the global population
Evolving patterns of extreme publishing behavior across science
The Subjective Interpretation of the Medical Evidence
This Viewpoint discusses whether commonly occuring, sometimes divergent interpretations of new evidence’s validity and usefulness should be explained when experts and guideline committees provide recommendations for screening or treatment
Is society caught up in a Death Spiral? Modeling societal demise and its reversal
Just like an army of ants caught in an ant mill, individuals, groups and even whole societies are sometimes caught up in a Death Spiral, a vicious cycle of self-reinforcing dysfunctional behavior characterized by continuous flawed decision making, myopic single-minded focus on one (set of) solution(s), denial, distrust, micromanagement, dogmatic thinking and learned helplessness. We propose the term Death Spiral Effect to describe this difficult-…
Prolific non-research authors in high impact scientific journals
Lessons learnt from registration of biomedical research
Aggressive measures, rising inequalities, and mass formation during the Covid-19 crisis
A series of aggressive restrictive measures were adopted around the world in 2020–2022 to attempt to prevent SARS-CoV-2 from spreading. However, it has become increasingly clear the most aggressive (lockdown) response strategies may involve negative side-effects such as a steep increase in poverty, hunger, and inequalities. Several economic, educational, and health repercussions have fallen disproportionately on children, students, young workers,…
Estimating the Prevalence of Transparency and Reproducibility-Related Research Practices in Psychology (2014–2017)
Psychologists are navigating an unprecedented period of introspection about the credibility and utility of their discipline. Reform initiatives emphasize the benefits of transparency and reproducibility-related research practices; however, adoption across the psychology literature is unknown. Estimating the prevalence of such practices will help to gauge the collective impact of reform initiatives, track progress over time, and calibrate future e…
Preventive psychiatry
Preventive approaches have latterly gained traction for improving mental health in young people. In this paper, we first appraise the conceptual foundations of preventive psychiatry, encompassing the public health, Gordon's, US Institute of Medicine, World Health Organization, and good mental health frameworks, and neurodevelopmentally‐sensitive clinical staging models. We then review the evidence supporting primary prevention of psychotic, bipol…
Inverse correlates of Covid-19 mortality across European countries during the first versus subsequent waves
The objectives of the study were to calculate the standardised mortality rates (SMRs) for COVID-19 in European Union/European Economic Area countries plus the UK and Switzerland and to evaluate the correlation between SMRs and selected indicators in the first versus the subsequent waves until 23 June 2021. We used indirect standardisation (using Italy as the reference) to compute SMRs and considered 16 indicators of health and social well-being, …
Precision shielding for Covid-19
The ability to preferentially protect high-risk groups in COVID-19 is hotly debated. Here, the aim is to present simple metrics of such precision shielding of people at high risk of death after infection by SARS-CoV-2; demonstrate how they can estimated; and examine whether precision shielding was successfully achieved in the first COVID-19 wave. The shielding ratio, S, is defined as the ratio of prevalence of infection among people in a high-ris…
Comprehensive mapping of local and diaspora scientists
Research policy and planning for a given country may benefit from reliable data on both its scientific workforce as well as the diaspora of scientists for countries with a substantial brain drain. Here we use a systematic approach using Scopus to generate a comprehensive country-level database of all scientists in Greece. Moreover, we expand that database to include also Greek diaspora scientists. The database that we have compiled includes 63,95…
Science, advocacy, and quackery in nutritional books
Nutritional decisions may be important for health, and yet identifying trustworthy sources of advice can be difficult to achieve. Many people turn to books for nutritional advice, making the contents of these books and the expertise of their authors relevant to public health. Here, the top 100 best-selling books were identified and assessed for both the claims they make in their summaries and the credentials of the authors. Weight loss was a comm…
Evidence Relating Health Care Provider Burnout and Quality of Care
Background: Whether health care provider burnout contributes to lower quality of patient care is unclear. Purpose: To estimate the overall relationship between burnout and quality of care and to evaluate whether published studies provide exaggerated estimates of this relationship. Data Sources: MEDLINE, PsycINFO, Health and Psychosocial Instruments (EBSCO), Mental Measurements Yearbook (EBSCO), EMBASE (Elsevier), and Web of Science (Clarivate Ana…
A consensus-based transparency checklist
We present a consensus-based checklist to improve and document the transparency of research reports in social and behavioural research. An accompanying online application allows users to complete the form and generate a report that they can submit with their manuscript or post to a public repository
Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder
Randomized controlled trials
Mapping the universe of registered reports
Empirical assessment of published effect sizes and power in the recent cognitive neuroscience and psychology literature
We have empirically assessed the distribution of published effect sizes and estimated power by analyzing 26,841 statistical records from 3,801 cognitive neuroscience and psychology papers published recently. The reported median effect size was D = 0.93 (interquartile range: 0.64-1.46) for nominally statistically significant results and D = 0.24 (0.11-0.42) for nonsignificant results. Median power to detect small, medium, and large effects was 0.1…
The Power of Bias in Economics Research
We investigate two critical dimensions of the credibility of empirical economics research: statistical power and bias. We survey 159 empirical economics literatures that draw upon 64,076 estimates of economic parameters reported in more than 6,700 empirical studies. Half of the research areas have nearly 90% of their results under‐powered. The median statistical power is 18%, or less. A simple weighted average of those reported results that are a…
Redefine statistical significance
A manifesto for reproducible science
Improving the reliability and efficiency of scientific research will increase the credibility of the published scientific literature and accelerate discovery. Here we argue for the adoption of measures to optimize key elements of the scientific process: methods, reporting and dissemination, reproducibility, evaluation and incentives. There is some evidence from both simulations and empirical studies supporting the likely effectiveness of these me…
Does evidence-based hearsay determine the use of medical treatments
Redefine statistical significance
A manifesto for reproducible science
Improving the reliability and efficiency of scientific research will increase the credibility of the published scientific literature and accelerate discovery. Here we argue for the adoption of measures to optimize key elements of the scientific process: methods, reporting and dissemination, reproducibility, evaluation and incentives. There is some evidence from both simulations and empirical studies supporting the likely effectiveness of these me…
The Power of Bias in Economics Research
We investigate two critical dimensions of the credibility of empirical economics research: statistical power and bias. We survey 159 empirical economics literatures that draw upon 64,076 estimates of economic parameters reported in more than 6,700 empirical studies. Half of the research areas have nearly 90% of their results under‐powered. The median statistical power is 18%, or less. A simple weighted average of those reported results that are a…
Mapping the universe of registered reports
A consensus-based transparency checklist
We present a consensus-based checklist to improve and document the transparency of research reports in social and behavioural research. An accompanying online application allows users to complete the form and generate a report that they can submit with their manuscript or post to a public repository
Does evidence-based hearsay determine the use of medical treatments
Is society caught up in a Death Spiral? Modeling societal demise and its reversal
Just like an army of ants caught in an ant mill, individuals, groups and even whole societies are sometimes caught up in a Death Spiral, a vicious cycle of self-reinforcing dysfunctional behavior characterized by continuous flawed decision making, myopic single-minded focus on one (set of) solution(s), denial, distrust, micromanagement, dogmatic thinking and learned helplessness. We propose the term Death Spiral Effect to describe this difficult-…
Lessons learnt from registration of biomedical research
Placing epidemiological results in the context of multiplicity and typical correlations of exposures
Epidemiological studies evaluate multiple exposures, but the extent of multiplicity often remains non-transparent when results are reported. There is extensive debate in the literature on whether multiplicity should be adjusted for in the design, analysis, and reporting of most epidemiological studies, and, if so, how this should be done. The challenges become more acute in an era where the number of exposures that can be studied (the exposome ) …
Genetic and molecular epidemiology
Genetic and molecular epidemiology covers a vast area of research. Given the rapid changes in this field, discussing a research agenda is a precarious and ambitious task. A representative set of high-priority concepts will be presented here, each of which alone could be the topic of a long series of essays. The wish list includes issues of full transparency and integration of information, dealing efficiently with complex multidimensional biology,…
The Role of Trust Management in Distributed Systems Security
Contradicted and Initially Stronger Effects in Highly Cited Clinical Research
CONTEXT: Controversy and uncertainty ensue when the results of clinical research on the effectiveness of interventions are subsequently contradicted. Controversies are most prominent when high-impact research is involved. OBJECTIVES: To understand how frequently highly cited studies are contradicted or find effects that are stronger than in other similar studies and to discern whether specific characteristics are associated with such refutation o…
Self-Reported Health in High and Very High Incomes
Meta-Analysis of Fractional Flow Reserve Versus Quantitative Coronary Angiography and Noninvasive Imaging for Evaluation of Myocardial Ischemia
We performed a meta-analysis of 31 studies comparing the results of fractional flow reserve (FFR) against quantitative coronary angiography (QCA) and/or noninvasive imaging of the same lesions. Studies were retrieved from PubMed (last search February 2006). Across 18 studies (1,522 lesions), QCA had a random effects sensitivity of 78% (95% confidence interval [CI] 67 to 86) and specificity of 51% (95% CI 40 to 61) against FFR (0.75 cutoff). Overa…
Genetic and molecular epidemiology
Genetic and molecular epidemiology covers a vast area of research. Given the rapid changes in this field, discussing a research agenda is a precarious and ambitious task. A representative set of high-priority concepts will be presented here, each of which alone could be the topic of a long series of essays. The wish list includes issues of full transparency and integration of information, dealing efficiently with complex multidimensional biology,…
Why Most Discovered True Associations Are Inflated
Newly discovered true (non-null) associations often have inflated effects compared with the true effect sizes. I discuss here the main reasons for this inflation. First, theoretical considerations prove that when true discovery is claimed based on crossing a threshold of statistical significance and the discovery study is underpowered, the observed effects are expected to be inflated. This has been demonstrated in various fields ranging from earl…
Systematic Review of the Empirical Evidence of Study Publication Bias and Outcome Reporting Bias
The PRISMA Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions
The PRISMA Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions
The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions
Recommendations for examining and interpreting funnel plot asymmetry in meta-analyses of randomised controlled trials
Funnel plots, and tests for funnel plot asymmetry, have been widely used to examine bias in the results of meta-analyses. Funnel plot asymmetry should not be equated with publication bias, because it has a number of other possible causes. This article describes how to interpret funnel plot asymmetry, recommends appropriate tests, and explains the implications for choice of meta-analysis model
STrengthening the Reporting of OBservational studies in Epidemiology
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 a…
Why Science Is Not Necessarily Self-Correcting
The ability to self-correct is considered a hallmark of science. However, self-correction does not always happen to scientific evidence by default. The trajectory of scientific credibility can fluctuate over time, both for defined scientific fields and for science at-large. History suggests that major catastrophes in scientific credibility are unfortunately possible and the argument that “it is obvious that progress is made” is weak. Careful eval…
Antifragile
The acclaimed author of the influential bestseller The Black Swan, Nicholas Nassim Taleb takes a next big step with a deceptively simple concept: the "antifragile." Like the Greek hydra that grows two heads for each one it loses, people, systems, and institutions that are antifragile not only withstand shocks, they benefit from them. In a modern world dominated by chaos and uncertainty, Antifragile is a revolutionary vision from one of the most s…
Power failure
How to Make More Published Research True
In a 2005 paper that has been accessed more than a million times, John Ioannidis explained why most published research findings were false. Here he revisits the topic, this time to address how to improve matters. Please see later in the article for the Editors' Summary.
How to increase value and reduce waste when research priorities are set
Placing epidemiological results in the context of multiplicity and typical correlations of exposures
Epidemiological studies evaluate multiple exposures, but the extent of multiplicity often remains non-transparent when results are reported. There is extensive debate in the literature on whether multiplicity should be adjusted for in the design, analysis, and reporting of most epidemiological studies, and, if so, how this should be done. The challenges become more acute in an era where the number of exposures that can be studied (the exposome ) …
A vision for chronic disease prevention and intervention research
The PRISMA Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-analyses of Health Care Interventions
Translational Research May Be Most Successful When It Fails
In this issue of the Hastings Center Report, Jonathan Kimmelman and Alex London argue that in assessing the success of clinical translation, it is narrow‐minded to focus only on how many new drugs get licensed and how quickly they achieve licensure. Kimmelman and London show that clinical translation should be judged on its ability to generate as comprehensive an intervention ensemble as possible for the tested interventions. I would like to exte…
Health outcomes during the 2008 financial crisis in Europe
What does research reproducibility mean?
The language and conceptual framework of “research reproducibility” are nonstandard and unsettled across the sciences.
Plea for routinely presenting prediction intervals in meta-analysis
OBJECTIVES: Evaluating the variation in the strength of the effect across studies is a key feature of meta-analyses. This variability is reflected by measures like τ(2) or I(2), but their clinical interpretation is not straightforward. A prediction interval is less complicated: it presents the expected range of true effects in similar studies. We aimed to show the advantages of having the prediction interval routinely reported in meta-analyses. D…
The Mass Production of Redundant, Misleading, and Conflicted Systematic Reviews and Meta‐analyses
Medicine (23 works) · Computer Science (19 works) · Meta-analysis and systematic reviews (18 works) · Political science (16 works) · Psychology (16 works) · Mathematics (9 works) · Law (8 works) · Statistics (8 works) · Data science (7 works) · Pathology (7 works)