Evangelia Kitsiou

Summary

Affiliation: University of Ioannina
Country: Greece

Publications

  1. ncbi request reprint Non-replication and inconsistency in the genome-wide association setting
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Biomedical Research Institute Foundation for Research and Technology Hellas, Ioannina, Greece
    Hum Hered 64:203-13. 2007
  2. pmc Measuring co-authorship and networking-adjusted scientific impact
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    PLoS ONE 3:e2778. 2008
  3. pmc Reporting and interpretation of SF-36 outcomes in randomised trials: systematic review
    Despina G Contopoulos-Ioannidis
    Department of Paediatrics, University of Ioannina School of Medicine, Ioannina, Greece
    BMJ 338:a3006. 2009
  4. pmc Selection and presentation of imaging figures in the medical literature
    George C M Siontis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 5:e10888. 2010
  5. pmc Evaluation of association of HNF1B variants with diverse cancers: collaborative analysis of data from 19 genome-wide association studies
    Katherine S Elliott
    Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
    PLoS ONE 5:e10858. 2010
  6. pmc Meta-analysis in genome-wide association datasets: strategies and application in Parkinson disease
    Evangelos Evangelou
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 2:e196. 2007
  7. pmc Concentration of the most-cited papers in the scientific literature: analysis of journal ecosystems
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 1:e5. 2006
  8. pmc Assessing and reporting heterogeneity in treatment effects in clinical trials: a proposal
    David M Kent
    Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA, USA
    Trials 11:85. 2010
  9. pmc Association of RGS4 variants with schizotypy and cognitive endophenotypes at the population level
    Nicholas C Stefanis
    University Mental Health Research Institute, Athens, Greece
    Behav Brain Funct 4:46. 2008
  10. pmc Reporting of conflicts of interest in guidelines of preventive and therapeutic interventions
    G N Papanikolaou
    Clinical Trials and Evidence Based Medicine Unit, and Social Medicine and Public Health Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    BMC Med Res Methodol 1:3. 2001

Collaborators

Detail Information

Publications110 found, 100 shown here

  1. ncbi request reprint Non-replication and inconsistency in the genome-wide association setting
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Biomedical Research Institute Foundation for Research and Technology Hellas, Ioannina, Greece
    Hum Hered 64:203-13. 2007
    ..A list of options is presented for consideration in each of these scenarios...
  2. pmc Measuring co-authorship and networking-adjusted scientific impact
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    PLoS ONE 3:e2778. 2008
    ..Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles...
  3. pmc Reporting and interpretation of SF-36 outcomes in randomised trials: systematic review
    Despina G Contopoulos-Ioannidis
    Department of Paediatrics, University of Ioannina School of Medicine, Ioannina, Greece
    BMJ 338:a3006. 2009
    ..To determine how often health surveys and quality of life evaluations reach different conclusions from those of primary efficacy outcomes and whether discordant results make a difference in the interpretation of trial findings...
  4. pmc Selection and presentation of imaging figures in the medical literature
    George C M Siontis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 5:e10888. 2010
    ..We therefore evaluated the selection and presentation of radiological imaging figures in major medical journals...
  5. pmc Evaluation of association of HNF1B variants with diverse cancers: collaborative analysis of data from 19 genome-wide association studies
    Katherine S Elliott
    Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
    PLoS ONE 5:e10858. 2010
    ..We aimed to identify whether these variants may have an effect on cancer risk in general versus a specific effect on prostate cancer only...
  6. pmc Meta-analysis in genome-wide association datasets: strategies and application in Parkinson disease
    Evangelos Evangelou
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 2:e196. 2007
    ..However, for the detection of small genetic effects, single studies may be underpowered. Power may be improved by combining genome-wide datasets with meta-analytic techniques...
  7. pmc Concentration of the most-cited papers in the scientific literature: analysis of journal ecosystems
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 1:e5. 2006
    ..A minority of scientific journals publishes the majority of scientific papers and receives the majority of citations. The extent of concentration of the most influential articles is less well known...
  8. pmc Assessing and reporting heterogeneity in treatment effects in clinical trials: a proposal
    David M Kent
    Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, MA, USA
    Trials 11:85. 2010
    ..A standardized and transparent approach to HTE assessment and reporting could substantially improve clinical trial utility and interpretability...
  9. pmc Association of RGS4 variants with schizotypy and cognitive endophenotypes at the population level
    Nicholas C Stefanis
    University Mental Health Research Institute, Athens, Greece
    Behav Brain Funct 4:46. 2008
    ..abstract:..
  10. pmc Reporting of conflicts of interest in guidelines of preventive and therapeutic interventions
    G N Papanikolaou
    Clinical Trials and Evidence Based Medicine Unit, and Social Medicine and Public Health Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    BMC Med Res Methodol 1:3. 2001
    ....
  11. pmc Reporting of human genome epidemiology (HuGE) association studies: an empirical assessment
    Ajay Yesupriya
    National Office of Public Health Genomics, Coordinating Center for Health Promotion, Centers for Disease Control and Prevention, Atlanta, USA
    BMC Med Res Methodol 8:31. 2008
    ..Transparent reporting of study methods and results allows readers to better assess the validity of study findings. Here, we document reporting practices of human genome epidemiology studies...
  12. pmc Determinants of patient recruitment in a multicenter clinical trials group: trends, seasonality and the effect of large studies
    A B Haidich
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    BMC Med Res Methodol 1:4. 2001
    ..Analyses were performed in two datasets: one included all studies and substudies (n = 475, total enrollment 69,992 patients) and the other included only main studies (n = 352, total enrollment 57,563 patients)...
  13. pmc International ranking systems for universities and institutions: a critical appraisal
    John P A Ioannidis
    BMC Med 5:30. 2007
    ..Ranking of universities and institutions has attracted wide attention recently. Several systems have been proposed that attempt to rank academic institutions worldwide...
  14. pmc Appendicectomies in Albanians in Greece: outcomes in a highly mobile immigrant patient population
    A Tatsioni
    Department of Hygiene and Epidemiology, Medical School, University of loannina, 451 10 Ioannina, Greece
    BMC Health Serv Res 1:5. 2001
    ..We used data from 6 hospitals in the Greek prefecture of Epirus that is bordering Albania...
  15. pmc Open letter to the leader of academic medicine
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    BMJ 334:191-3. 2007
  16. ncbi request reprint Assessment of cumulative evidence on genetic associations: interim guidelines
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Int J Epidemiol 37:120-32. 2008
    ..Future empirical research and consensus development are needed to develop an integrated model for combining epidemiological and biological evidence in the rapidly evolving field of investigation of genetic factors...
  17. pmc Heterogeneity in meta-analyses of genome-wide association investigations
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS ONE 2:e841. 2007
    ..Between-study heterogeneity is important to document and may point to interesting leads...
  18. pmc Genetic and molecular epidemiology
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    J Epidemiol Community Health 61:757-8. 2007
    ....
  19. ncbi request reprint Selective discussion and transparency in microarray research findings for cancer outcomes
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Eur J Cancer 43:1999-2010. 2007
    ..Only three studies had scanned images, raw and processed data available. Processing details varied. Public transparency and unbiased interpretation of findings can be improved in microarray research...
  20. ncbi request reprint A road map for efficient and reliable human genome epidemiology
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina 45110, Greece
    Nat Genet 38:3-5. 2006
    ..Systematic reviews will be expanded to include more meta-analyses of individual-level data and prospective meta-analyses. Field synopses will offer regularly updated overviews...
  21. ncbi request reprint Commentary: grading the credibility of molecular evidence for complex diseases
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Int J Epidemiol 35:572-8; discussion 593-6. 2006
  22. ncbi request reprint Molecular evidence-based medicine: evolution and integration of information in the genomic era
    J P A Ioannidis
    University of Ioannina School of Medicine, Greece
    Eur J Clin Invest 37:340-9. 2007
    ..Research efforts should be integrated across teams in an open, sharing environment. Most research in the future may be designed, performed, and integrated in the public cyberspace...
  23. pmc The appropriateness of asymmetry tests for publication bias in meta-analyses: a large survey
    John P A Ioannidis
    Tufts University School of Medicine, Boston, Mass, USA
    CMAJ 176:1091-6. 2007
    ..Inappropriate application can generate misleading inferences about publication bias. We aimed to measure, in a survey of meta-analyses, how frequently the application of these tests would be not meaningful or inappropriate...
  24. ncbi request reprint Implications of small effect sizes of individual genetic variants on the design and interpretation of genetic association studies of complex diseases
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Am J Epidemiol 164:609-14. 2006
    ..These collaborative studies ideally should be designed up front to also assess more complex gene-gene and gene-environment interactions...
  25. ncbi request reprint Is molecular profiling ready for use in clinical decision making?
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Oncologist 12:301-11. 2007
    ..Overall, molecular profiling is a fascinating and promising technology, but its incorporation into clinical decision making requires careful planning and robust evidence...
  26. ncbi request reprint Extreme between-study homogeneity in meta-analyses could offer useful insights
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Clin Epidemiol 59:1023-32. 2006
    ..Meta-analyses are routinely evaluated for the presence of large between-study heterogeneity. We examined whether it is also important to probe whether there is extreme between-study homogeneity...
  27. ncbi request reprint Indirect comparisons: the mesh and mess of clinical trials
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Lancet 368:1470-2. 2006
  28. ncbi request reprint Limitations are not properly acknowledged in the scientific literature
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Clin Epidemiol 60:324-9. 2007
    ..To facilitate this, journals should give better guidance and promote the discussion of limitations. Otherwise, we are facing an important loss of context for the scientific literature...
  29. pmc Uncertainty in heterogeneity estimates in meta-analyses
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    BMJ 335:914-6. 2007
  30. ncbi request reprint Nested randomized trials in large cohorts and biobanks: studying the health effects of lifestyle factors
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    Epidemiology 19:75-82. 2008
    ..The aim should be to combine carefully the strengths of both observational epidemiology and randomized research without compounding their limitations...
  31. ncbi request reprint Expectations, validity, and reality in omics
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece
    J Clin Epidemiol 63:945-9. 2010
    ..Given the exponential growth of collected data, understanding is often drowning in the sea of measurements...
  32. pmc A compendium of genome-wide associations for cancer: critical synopsis and reappraisal
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Natl Cancer Inst 102:846-58. 2010
    ..At present, the utility of GWA-identified risk loci in risk stratification for cancer is limited...
  33. doi request reprint Researching genetic versus nongenetic determinants of disease: a comparison and proposed unification
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Sci Transl Med 1:7ps8. 2009
    ..Current research designs that dissociate genetic and nongenetic measurements are reaching their limits. Studies are needed that massively measure genotypes, nongenetic exposures, and outcomes concurrently...
  34. doi request reprint Prediction of cardiovascular disease outcomes and established cardiovascular risk factors by genome-wide association markers
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Circ Cardiovasc Genet 2:7-15. 2009
    ..Genome-wide association (GWA) platforms have yielded a rapidly increasing number of new genetic markers. The ability of these markers to improve prediction of clinically important outcomes is debated...
  35. doi request reprint Perfect study, poor evidence: interpretation of biases preceding study design
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    Semin Hematol 45:160-6. 2008
    ..The concerted presence of such biases may have a multiplicative, detrimental impact on the scientific literature. These issues should be considered carefully when interpreting research results...
  36. doi request reprint Susceptibility variants for rheumatoid arthritis in the TRAF1-C5 and 6q23 loci: a meta-analysis
    Nikolaos A Patsopoulos
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Ann Rheum Dis 69:561-6. 2010
    ..Furthermore, additional independent studies have investigated the same or highly linked polymorphisms in the same regions...
  37. doi request reprint Validating, augmenting and refining genome-wide association signals
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina 45110, Greece
    Nat Rev Genet 10:318-29. 2009
    ..Even in cases for which replication proves that an effect exists, confident localization of the causal variant often remains elusive...
  38. ncbi request reprint Repeatability of published microarray gene expression analyses
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Nat Genet 41:149-55. 2009
    ..Repeatability of published microarray studies is apparently limited. More strict publication rules enforcing public data availability and explicit description of data processing and analysis should be considered...
  39. doi request reprint Interpretation of tests of heterogeneity and bias in meta-analysis
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    J Eval Clin Pract 14:951-7. 2008
    ..Suggestions are made on how to avoid these flaws, use these tests properly and learn from them...
  40. ncbi request reprint Why most discovered true associations are inflated
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Epidemiology 19:640-8. 2008
    ....
  41. ncbi request reprint Effect of formal statistical significance on the credibility of observational associations
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Am J Epidemiol 168:374-83; discussion 384-90. 2008
    ..Bayes factors may be used routinely to interpret "significant" associations...
  42. pmc Reasons or excuses for avoiding meta-analysis in forest plots
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina 45110, Greece
    BMJ 336:1413-5. 2008
  43. ncbi request reprint Some main problems eroding the credibility and relevance of randomized trials
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece 45110
    Bull NYU Hosp Jt Dis 66:135-9. 2008
    ....
  44. pmc Effectiveness of antidepressants: an evidence myth constructed from a thousand randomized trials?
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and the Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    Philos Ethics Humanit Med 3:14. 2008
    ....
  45. ncbi request reprint Calibration of credibility of agnostic genome-wide associations
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Am J Med Genet B Neuropsychiatr Genet 147:964-72. 2008
    ..Credibility calibration may be used in conjunction with qualitative criteria for the appraisal of the cumulative evidence that take into consideration the amount, consistency, and protection from bias in the data...
  46. doi request reprint Is there a glass ceiling for highly cited scientists at the top of research universities?
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, 45110, Greece
    FASEB J 24:4635-8. 2010
    ..0. The participation of highly cited scientists in the top leadership of universities is limited. This could have consequences for the research and overall mission of universities...
  47. ncbi request reprint Perinatal transmission of human immunodeficiency virus type 1 by pregnant women with RNA virus loads <1000 copies/ml
    J P Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Infect Dis 183:539-45. 2001
    ..Perinatal HIV-1 transmission occurs in only 1% of treated women with RNA virus loads <1000 copies/mL and may be almost eliminated with antiretroviral prophylaxis accompanied by suppression of maternal viremia...
  48. ncbi request reprint Differential genetic effects of ESR1 gene polymorphisms on osteoporosis outcomes
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    JAMA 292:2105-14. 2004
    ..Estrogen receptor alpha (ESR1) is a candidate gene for osteoporosis, but previous studies of ESR1 polymorphisms in this field were hampered by small sample size, lack of standardization, and inconclusive results...
  49. pmc Large scale evidence and replication: insights from rheumatology and beyond
    J P A Ioannidis
    Ioannina School of Medicine, Ioannina, Greece
    Ann Rheum Dis 64:345-6. 2005
  50. ncbi request reprint The value of meta-analysis in rheumatology research
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, 45110, Greece
    Autoimmun Rev 3:S57-9. 2004
  51. ncbi request reprint Mortality risk conferred by small elevations of creatine kinase-MB isoenzyme after percutaneous coronary intervention
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and the Biomedical Research Institute, Foundation for Research and Technology, Hellas Ioannina, Greece
    J Am Coll Cardiol 42:1406-11. 2003
    ..The aim of this study was to assess whether small creatine kinase-MB isoenzyme (CK-MB) elevations after percutaneous coronary intervention (PCI) affect the subsequent mortality risk...
  52. ncbi request reprint Maternal viral load and rate of disease progression among vertically HIV-1-infected children: an international meta-analysis
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    AIDS 18:99-108. 2004
    ....
  53. ncbi request reprint HIV lipodystrophy case definition using artificial neural network modelling
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Antivir Ther 8:435-41. 2003
    ..We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy...
  54. ncbi request reprint Effects of CCR5-delta32 and CCR2-64I alleles on disease progression of perinatally HIV-1-infected children: an international meta-analysis
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    AIDS 17:1631-8. 2003
    ..Among perinatally infected children, the effects of certain alleles of the CCR5 and CCR2 genes on the rate of disease progression remain unclear. We addressed the effects of CCR5-delta32 and CCR2-64I in an international meta-analysis...
  55. ncbi request reprint Genetic associations: false or true?
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine and Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    Trends Mol Med 9:135-8. 2003
    ..However, a sizeable proportion of identified genetic associations are probably true. Meta-analysis, a rigorous, comprehensive, quantitative synthesis of all the available data, might help us to separate the true from the false...
  56. ncbi request reprint Genetic associations in large versus small studies: an empirical assessment
    John P A Ioannidis
    Department of Hygiene, University of Ioannina School of Medicine, Ioannina, Greece
    Lancet 361:567-71. 2003
    ..Our aim was to assess how often large studies arrive at different conclusions than smaller studies, and whether this situation arises more frequently when findings of first published studies disagree with those of subsequent research...
  57. ncbi request reprint Evaluation of the association of autoantibodies with mortality in the very elderly: a cohort study
    J P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece
    Rheumatology (Oxford) 42:357-61. 2003
    ..To evaluate whether autoantibodies in the absence of rheumatic diseases increase the risk of mortality among very elderly subjects who are otherwise in good functional condition...
  58. ncbi request reprint Global estimates of high-level brain drain and deficit
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    FASEB J 18:936-9. 2004
    ..Scientific deficit is only likely to help perpetuate these adverse conditions...
  59. ncbi request reprint Predictors of sustained amenorrhea from pulsed intravenous cyclophosphamide in premenopausal women with systemic lupus erythematosus
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    J Rheumatol 29:2129-35. 2002
    ..To identify predictors of intravenous cyclophosphamide (IC) induced sustained amenorrhea, especially in young premenopausal women with systemic lupus erythematosus (SLE)...
  60. ncbi request reprint Long-term risk of mortality and lymphoproliferative disease and predictive classification of primary Sjögren's syndrome
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Arthritis Rheum 46:741-7. 2002
    ..We sought to determine the incidence and predictors of adverse long-term outcomes to achieve a rational predictive classification of the syndrome...
  61. ncbi request reprint Replication validity of genetic association studies
    J P Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Nat Genet 29:306-9. 2001
    ..We conclude that a systematic meta-analytic approach may assist in estimating population-wide effects of genetic risk factors in human disease...
  62. ncbi request reprint Bias in uncontrolled therapeutic trials in rheumatology due to selection of populations with extreme characteristics
    J P Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece
    J Rheumatol 28:1881-7. 2001
    ..To assess the prevalence of biases from selection of patients with extreme characteristics in recent uncontrolled therapeutic studies in rheumatology...
  63. ncbi request reprint 'Racial' differences in genetic effects for complex diseases
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Nat Genet 36:1312-8. 2004
    ..Genetic markers for proposed gene-disease associations vary in frequency across populations, but their biological impact on the risk for common diseases may usually be consistent across traditional 'racial' boundaries...
  64. ncbi request reprint Mortality in systemic sclerosis: an international meta-analysis of individual patient data
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Am J Med 118:2-10. 2005
    ..Studies on mortality associated with systemic sclerosis have been limited by small sample sizes. We aimed to obtain large-scale evidence on survival outcomes and predictors for this disease...
  65. pmc Why most published research findings are false
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    PLoS Med 2:e124. 2005
    ..In this essay, I discuss the implications of these problems for the conduct and interpretation of research...
  66. ncbi request reprint A network of investigator networks in human genome epidemiology
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Am J Epidemiol 162:302-4. 2005
    ....
  67. ncbi request reprint Comparison of large versus smaller randomized trials for mental health-related interventions
    Despina G Contopoulos-Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Am J Psychiatry 162:578-84. 2005
    ..The extent of disagreement between large and smaller randomized, controlled trials on mental health issues is unknown. The authors aimed to compare the results of large versus smaller trials on mental health-related interventions...
  68. ncbi request reprint Contradicted and initially stronger effects in highly cited clinical research
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    JAMA 294:218-28. 2005
    ..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...
  69. ncbi request reprint An exploratory test for an excess of significant findings
    John P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit and Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Clin Trials 4:245-53. 2007
    ..The published clinical research literature may be distorted by the pursuit of statistically significant results...
  70. ncbi request reprint Molecular bias
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Eur J Epidemiol 20:739-45. 2005
    ..Issues of plausibility (in particular biological plausibility), replication, and credibility that form the theoretical basis of epidemiology and etiological inference can now be approached with large-scale empirical data...
  71. ncbi request reprint Microarrays and molecular research: noise discovery?
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Lancet 365:454-5. 2005
  72. ncbi request reprint Early extreme contradictory estimates may appear in published research: the Proteus phenomenon in molecular genetics research and randomized trials
    John P A Ioannidis
    Institute for Clinical Research and Health Policy Studies, Department of Medicine, Tufts New England Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA
    J Clin Epidemiol 58:543-9. 2005
    ..We hypothesized that controversial data are attractive to investigators and editors, and thus the most extreme, opposite results would appear very early rather than late, as data accumulate, provided data can be generated rapidly...
  73. ncbi request reprint Safety reporting in randomized trials of mental health interventions
    Panagiotis N Papanikolaou
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Am J Psychiatry 161:1692-7. 2004
    ..The authors aimed to evaluate the adequacy of the reporting of safety information in publications of randomized trials of mental-health-related interventions...
  74. ncbi request reprint Association of polymorphisms of the estrogen receptor alpha gene with bone mineral density and fracture risk in women: a meta-analysis
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece
    J Bone Miner Res 17:2048-60. 2002
    ..In summary, we have found that XX homozygotes may have higher BMD and also a decreased risk of fractures when compared with carriers of the x allele, whereas the PvuII polymorphism is not associated with either BMD or fracture risk...
  75. ncbi request reprint Association of polymorphisms of the oestrogen receptor alpha gene with the age of menarche
    I Stavrou
    Division of Endocrinology, Department of Internal Medicine, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Hum Reprod 17:1101-5. 2002
    ..We evaluated whether the XbaI and PvuII polymorphisms of the estrogen receptor alpha gene are associated with the age of menarche...
  76. ncbi request reprint Ala45Thr polymorphism of the NEUROD1 gene and diabetes susceptibility: a meta-analysis
    Fotini K Kavvoura
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, 45110, Greece
    Hum Genet 116:192-9. 2005
    ..083). The Ala45Thr polymorphism of the NEUROD1 gene has no effect on susceptibility to T2D. It may however be a risk factor for susceptibility to T1D, in particular for subjects of Asian descent, although bias cannot be totally excluded...
  77. ncbi request reprint Concordance of functional in vitro data and epidemiological associations in complex disease genetics
    John P A Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Genet Med 8:583-93. 2006
    ..We aimed to assess whether epidemiological evidence on genetic associations for complex diseases concord with in vitro functional data...
  78. ncbi request reprint Association of the CYP17 gene polymorphism with the risk of prostate cancer: a meta-analysis
    Christos Ntais
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Greece
    Cancer Epidemiol Biomarkers Prev 12:120-6. 2003
    ..Previously reported associations may reflect publication bias, although it is also possible that the polymorphism may be important in subjects of African descent...
  79. ncbi request reprint CYP2D6 polymorphisms and the risk of tardive dyskinesia in schizophrenia: a meta-analysis
    Nikolaos A Patsopoulos
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Pharmacogenet Genomics 15:151-8. 2005
    ..003). CYP2D6 loss of function alleles may predispose to tardive dyskinesia in patients with schizophrenia under treatment, but bias cannot be excluded...
  80. ncbi request reprint Effect of CCR5-delta32 heterozygosity on the risk of perinatal HIV-1 infection: a meta-analysis
    Despina G Contopoulos-Ioannidis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Grece
    J Acquir Immune Defic Syndr 32:70-6. 2003
    ..Results were similar when adjusted for the available data on the CCR2-641 polymorphism (n = 1542). The meta-analysis clarifies that perinatal infection is not significantly altered by heterozygosity for CCR5-Delta32 in the child...
  81. ncbi request reprint Selective reporting biases in cancer prognostic factor studies
    Panayiotis A Kyzas
    Department of Hygiene and Epidemiology, School of Medicine, University of Ioannina, Ioannina, Greece
    J Natl Cancer Inst 97:1043-55. 2005
    ..We probed these biases in a meta-analysis of a prognostic factor for head and neck squamous cell cancer (HNSCC) mortality that has drawn wide attention--the status of the tumor suppressor protein TP53...
  82. ncbi request reprint Randomised trials comparing chemotherapy regimens for advanced non-small cell lung cancer: biases and evolution over time
    J P A Ioannidis
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, 45110, Ioannina, Greece
    Eur J Cancer 39:2278-87. 2003
    ..The proportion of enrolled patients with a performance status of 2 or worse decreased significantly over time (12.9% per decade, P<0.001). Randomised evidence in this field is fragmented and subject to considerable selection biases...
  83. doi request reprint Associations of polymorphisms of eight muscle- or metabolism-related genes with performance in Mount Olympus marathon runners
    Georgios I Tsianos
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45 110, Greece
    J Appl Physiol (1985) 108:567-74. 2010
    ..BDKRB2 rs1799722 and ADRB2 rs1042713 have some support for being implicated in endurance performance among habitual runners and require further investigation...
  84. ncbi request reprint Vitamin D receptor gene polymorphisms and risk of prostate cancer: a meta-analysis
    Christos Ntais
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Cancer Epidemiol Biomarkers Prev 12:1395-402. 2003
    ..03 (95% CI, 0.86-1.23; no between-study heterogeneity) for the f versus F allele. The meta-analysis shows that these four polymorphisms are unlikely to be major determinants of susceptibility to prostate cancer on a wide population basis...
  85. pmc Replication of past candidate loci for common diseases and phenotypes in 100 genome-wide association studies
    Konstantinos C M Siontis
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Eur J Hum Genet 18:832-7. 2010
    ..15-0.43). Overall, few of the numerous genetic associations proposed in the candidate gene era have been replicated in GWASs, but those that have been conclusively replicated have large genetic effects that should not be discarded...
  86. ncbi request reprint Quality of reporting of cancer prognostic marker studies: association with reported prognostic effect
    Panayiotis A Kyzas
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Natl Cancer Inst 99:236-43. 2007
    ..Issues of reported study quality have not been addressed empirically with large-scale data in the cancer prognostic literature...
  87. ncbi request reprint Cytotoxic T-lymphocyte associated antigen 4 gene polymorphisms and autoimmune thyroid disease: a meta-analysis
    Fotini K Kavvoura
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Clin Endocrinol Metab 92:3162-70. 2007
    ....
  88. ncbi request reprint Association of GSTM1, GSTT1, and GSTP1 gene polymorphisms with the risk of prostate cancer: a meta-analysis
    Christos Ntais
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    Cancer Epidemiol Biomarkers Prev 14:176-81. 2005
    ..For GSTT1, larger studies gave different results than smaller ones. The meta-analysis shows that these three polymorphisms are unlikely to be major determinants of susceptibility to prostate cancer on a wide population basis...
  89. ncbi request reprint Limited benefit of antiretroviral resistance testing in treatment-experienced patients: a meta-analysis
    Ermioni T Panidou
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    AIDS 18:2153-61. 2004
    ....
  90. ncbi request reprint Impact of violations and deviations in Hardy-Weinberg equilibrium on postulated gene-disease associations
    Thomas A Trikalinos
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45100, Greece
    Am J Epidemiol 163:300-9. 2006
    ..Postulated genetic associations with modest-sized odds ratios and borderline statistical significance may not be robust in such sensitivity analyses...
  91. ncbi request reprint Commentary: meta-analysis of individual participants' data in genetic epidemiology
    John P A Ioannidis
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, and Ioannina Biomedical Research Institute, Foundation for Research and Technology Hellas, Ioannina, Greece
    Am J Epidemiol 156:204-10. 2002
    ..For questions that justify the required intensive effort, the MIPD method is a useful tool to help clarify the role of candidate genes in complex human diseases...
  92. ncbi request reprint Large-scale analysis of association between GDF5 and FRZB variants and osteoarthritis of the hip, knee, and hand
    Evangelos Evangelou
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Arthritis Rheum 60:1710-21. 2009
    ..To examine these associations, we performed a large-scale meta-analysis of individual-level data...
  93. ncbi request reprint The Gini coefficient as a measure for understanding accrual inequalities in multicenter clinical studies
    Anna Bettina Haidich
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    J Clin Epidemiol 57:341-8. 2004
    ..Clinical sites participating in multicenter trials may have unequal performance in recruiting subjects. We propose using the Gini coefficient as a quantitative measure of site accrual inequalities...
  94. ncbi request reprint CTLA-4 gene polymorphisms and susceptibility to type 1 diabetes mellitus: a HuGE Review and meta-analysis
    Fotini K Kavvoura
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Am J Epidemiol 162:3-16. 2005
    ..99, 95% CI: 0.64, 1.55) or the *T allele of the C(-318)T polymorphism (OR = 0.92, 95% CI: 0.45, 1.89). This meta-analysis demonstrates that the CTLA-4*G genotype is associated with type 1 diabetes...
  95. ncbi request reprint Establishment of genetic associations for complex diseases is independent of early study findings
    Thomas A Trikalinos
    Clinical and Molecular Epidemiology Unit and Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Eur J Hum Genet 12:762-9. 2004
    ..Conversely, many genuine epidemiological associations would be missed, if research were abandoned after early underpowered 'negative' studies...
  96. ncbi request reprint Multiple-treatments meta-analysis of chemotherapy and targeted therapies in advanced breast cancer
    Davide Mauri
    Clinical Trials and Evidence Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    J Natl Cancer Inst 100:1780-91. 2008
    ..Many systemic nonhormonal regimens have been evaluated across several hundreds of randomized trials in advanced breast cancer. We aimed to quantify the relative merits of these regimens in prolonging survival...
  97. ncbi request reprint Association between maternal and infant class I and II HLA alleles and of their concordance with the risk of perinatal HIV type 1 transmission
    Anastasia Polycarpou
    Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece
    AIDS Res Hum Retroviruses 18:741-6. 2002
    ..79; p = 0.030) were retained as independent predictors of transmission. HLA alleles, and in particular the class I concordance between maternal and neonatal HLA, may regulate the risk of perinatal HIV-1 transmission...
  98. doi request reprint Evaluating novel agent effects in multiple-treatments meta-regression
    Georgia Salanti
    Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
    Stat Med 29:2369-83. 2010
    ....