Strengthening the Reporting of Genetic Risk Prediction Studies: The GRIPS Statement
Authors: A. Cecile J.W. Janssens
Journal: Annals of Internal Medicine (2011)

Research and Reporting Methods15 March 2011Strengthening the Reporting of Genetic Risk Prediction Studies: The GRIPS StatementFREEA. Cecile J.W. Janssens, PhD, John P.A. Ioannidis, MD, DSc, Cornelia M. van Duijn, PhD, Julian Little, PhD, and Muin J. Khoury, MD, PhD, for the GRIPS Group*A. Cecile J.W. Janssens, PhDFrom Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia., John P.A. Ioannidis, MD, DScFrom Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia., Cornelia M. van Duijn, PhDFrom Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia., Julian Little, PhDFrom Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia., and Muin J. Khoury, MD, PhDFrom Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia., for the GRIPS Group*Author, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-154-6-201103150-00008 SectionsAboutVisual AbstractPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail Key Summary PointsThe rapid and continuing progress in gene discovery for complex diseases is fueling interest in the potential application of genetic risk models for clinical and public health practice.The number of studies assessing the predictive ability is steadily increasing, but the quality and completeness of reporting varies.A multidisciplinary workshop sponsored by the Human Genome Epidemiology Network developed a checklist of 25 items recommended for strengthening the reporting of Genetic RIsk Prediction Studies (GRIPS), building on the principles established by prior reporting guidelines.These recommendations aim to enhance the transparency of study reporting, and thereby to improve the synthesis and application of information from multiple studies that might differ in design, conduct, or analysis.A detailed Explanation and Elaboration document is published at www.plosmedicine.org.Editor's Note: In order to encourage dissemination of the GRIPS Statement, this article is freely accessible onwww.annals.organd will also be published by PLoS Medicine, BMJ, Circulation: Cardiovascular Genetics, European Journal of Clinical Investigation, European Journal of Epidemiology, European Journal of Human Genetics, Genetics in Medicine, Genome Medicine, and Journal of Clinical Epidemiology.The recent successes of genome-wide association studies and the promises of whole genome sequencing fuel interest in the translation of this new wave of basic genetic knowledge to health care practice. Knowledge about genetic risk factors may be used to target diagnostic, preventive, and therapeutic interventions for complex disorders based on a person's genetic risk or to complement existing risk models based on classical nongenetic factors, such as the Framingham risk score for cardiovascular disease. Implementation of genetic risk prediction in health care requires a series of studies that encompass all phases of translational research (1, 2), starting with a comprehensive evaluation of genetic risk prediction.With increasing numbers of discovered genetic markers that can be used in future genetic risk prediction studies, it is crucial to enhance the quality of the reporting of these studies since valid interpretation could be compromised by the lack of reporting of key information. Information that is often missing includes details in the description of how the study was designed and conducted (for example, how genetic variants were selected and coded, how risk models or genetic risk scores were constructed, and how risk categories were chosen) or how the results should be interpreted. An appropriate assessment of the study's strengths and weaknesses is not possible without this information. There is ample evidence that prediction research often suffers from poor design and bias, and these may also have an impact on the results of the studies and on models of disease outcomes based on these studies (3–5). Although most prognostic studies published to date claim significant results (6, 7), very few translate to clinically useful applications. Just as for observational epidemiological studies (8), poor reporting complicates the use of the specific study for research, clinical, or public health purposes and hampers the synthesis of evidence across studies.Reporting guidelines have been published for various research designs (9), and these contain many items that are also relevant to genetic risk prediction studies. In particular, the guidelines for genetic association studies (STREGA) have relevant items on the assessment of genetic variants, and the guidelines for observational studies (STROBE) have relevant items about the reporting of study design. The guidelines for diagnostic studies (STARD) and those for tumor marker prognostic studies (REMARK) include relevant items about test evaluation; the REMARK guidelines also have relevant items about risk prediction (5, 10–12). However, none of these guidelines are fully suited to genetic risk prediction studies, an emerging field of investigation with specific methodological issues that need to be addressed, such as the handling of large numbers of genetic variants (from 10s to 10 000s) and flexibility in handling such large numbers in analyses. We organized a 2-day workshop with an international group of risk prediction researchers, epidemiologists, geneticists, methodologists, statisticians, and journal editors to develop recommendations for the reporting of Genetic RIsk Prediction Studies (GRIPS).Genetic Risk Prediction StudiesGenetic risk prediction studies typically develop or validate models that predict the risk of disease, but they are also being investigated for use in predicting prognostic outcome, treatment response, or treatment-related harms. Risk prediction models are statistical algorithms, which may be simple genetic risk scores (e.g., risk allele counts), regression analyses (e.g., weighted risk scores or predicted risks), or more complex analytic approaches, such as support vector machine learning or classification trees. The risk models may be based on genetic variants only or include both genetic and nongenetic risk factors (13).Aims and Use of the GRIPS StatementThe 25 items of the GRIPS statement are intended to maximize the transparency, quality, and completeness of reporting on research methodology and findings in a particular study. It is important to emphasize that these recommendations are guidelines only for how to report research and do not prescribe how to perform genetic risk prediction studies. The guidelines do not support or oppose the choice of any particular study design or method, e.g., the guidelines recommend that the study population should be described but do not specify which population is preferred in a particular study.The intended audience for the reporting guidelines is broad and includes epidemiologists, geneticists, statisticians, clinician scientists, and laboratory-based investigators who undertake genetic risk prediction studies, as well as journal editors and reviewers who have to appraise the design, conduct, and analysis of such studies. In addition, it includes "users" of such studies who wish to understand the basic premise, design, and limitations of genetic prediction studies in order to interpret the results for their potential application in health care. These guidelines are also intended to ensure that essential data from future genetic risk prediction studies are presented in standardized form, which will facilitate information synthesis as part of systematic reviews and meta-analyses.Items presented in the checklist are relevant for a wide array of risk prediction studies because GRIPS focuses on the main aspects of the design and analysis of risk prediction studies. GRIPS does not address randomized trials that may be performed to test risk models, nor does it specifically address decision analyses, cost-effectiveness analyses, assessment of health care needs, or assessment of barriers to health care implementation (14). Once the performance of a risk model has been established, these next steps toward implementation require further evaluation (10, 15). For the reporting of these studies, which go beyond the assessment of genetic risk models as such, additional requirements apply. However, proper documentation of genetic predictive research according to GRIPS might facilitate the translation of research findings into clinical and public health practice.Development of the GRIPS StatementThe GRIPS statement was developed by a multidisciplinary panel of 25 risk prediction researchers, epidemiologists, geneticists, methodologists, statisticians, and journal editors, 7 of whom were also part of the STREGA initiative (11). They attended a 2-day meeting in Atlanta, Georgia (United States) in December 2009 that was sponsored by the U.S. Centers for Disease Control and Prevention on behalf of the Human Genome Epidemiology Network (HuGENet) (16). Participants discussed a draft version of the guidelines that was prepared and distributed before the meeting. This draft version was developed on the basis of existing reporting guidelines, namely STREGA (11), REMARK (5), and STARD (12). These were selected out of all available guidelines (www.equator-network.org) because of their focus on observational study designs and genetic factors (STREGA), prediction models (REMARK), and test evaluation (REMARK and STARD). During the meeting, methodological issues pertinent to risk prediction studies were addressed in presentations. Workshop participants were asked to change, combine, or delete proposed items and add additional items if necessary. Participants had extensive electronic correspondence after the meeting. To harmonize our recommendations for genetic risk prediction studies with previous guidelines, we chose the same wording for the items wherever possible. Finally, we tried to create consistency with previous guidelines for the evaluation of risk prediction studies of cardiovascular diseases and cancer (2, 17). The final version of the checklist is presented in the Table.Table. Reporting Recommendations for Evaluations of Risk Prediction Models That Include Genetic VariantsThe GRIPS Explanation and Elaboration ArticleAccompanying this GRIPS statement, an Explanation and Elaboration document has been written (www.plosmedicine.org), modeled after those developed for other reporting guidelines (18–21). The Explanation and Elaboration document illustrates each item with at least 1 published example that we consider transparent in reporting, explains the rationale for its inclusion in the checklist, and presents details of the items that need to be addressed to ensure transparent reporting. The Explanation and Elaboration document was produced after the meeting. The document was prepared by a small subgroup and shared with all workshop participants for additional revisions and final approval.Concluding Remarks and Future DirectionsHigh-quality reporting reveals the strengths and weaknesses of empirical studies, facilitates the interpretation of the scientific and health care relevance of the results—especially within the framework of systematic reviews and meta-analyses—and helps build a solid evidence base for moving genomic discoveries into applications in health care practice. The GRIPS guidelines were developed to improve the transparency, quality, and completeness of the reporting of genetic risk prediction studies. As outlined in the introduction, GRIPS does not prescribe how studies should be designed, conducted, or analyzed, and therefore, the guidelines should not be used to assess the quality of empirical studies (22). The guidelines should be used only to check whether all essential items are adequately reported.Finally, the methodology for designing and assessing genetic risk prediction models is still developing. For example, newer measures of reclassification were first introduced in 2007 (23), and several alternative reclassification measures have been proposed (24). Which measures to apply and when to use measures of reclassification are still subject to ongoing evaluation and discussion (25). Furthermore, alternative strategies for constructing risk models other than simple regression analyses are being explored, and these may add increased complexity to the reporting. In formulating the items of the GRIPS statement, these methodological advances were anticipated. It is for this reason that the GRIPS statement recommends how a study should be reported and not how a study should be conducted or analyzed. Therefore, methodological and analytical developments will not immediately impact the validity and relevance of the items, but the GRIPS statement will be updated when this is warranted by essential new developments in the construction and evaluation of genetic risk models.References1. Khoury MJ, Gwinn M, Yoon PW, Dowling N, Moore CA, Bradley L. The continuum of translation research in genomic medicine: how can we accelerate the appropriate integration of human genome discoveries into health care and disease prevention? Genet Med. 2007;9:665-74. [PMID: 18073579] CrossrefMedlineGoogle Scholar2. Hlatky MA, Greenland P, Arnett DK, Ballantyne CM, Criqui MH, Elkind MS, et al; American Heart Association Expert Panel on Subclinical Atherosclerotic Diseases and Emerging Risk Factors and the Stroke Council. Criteria for evaluation of novel markers of cardiovascular risk: a scientific statement from the American Heart Association. Circulation. 2009;119:2408-16. [PMID: 19364974] CrossrefMedlineGoogle Scholar3. Kyzas PA, Denaxa-Kyza D, Ioannidis JP. Quality of reporting of cancer prognostic marker studies: association with reported prognostic effect. J Natl Cancer Inst. 2007;99:236-43. [PMID: 17284718] CrossrefMedlineGoogle Scholar4. Kyzas PA, Loizou KT, Ioannidis JP. Selective reporting biases in cancer prognostic factor studies. J Natl Cancer Inst. 2005;97:1043-55. [PMID: 16030302] CrossrefMedlineGoogle Scholar5. McShane LM, Altman DG, Sauerbrei W, Taube SE, Gion M, Clark GM; Statistics Subcommittee of the NCI-EORTC Working Group on Cancer Diagnostics. REporting recommendations for tumor MARKer prognostic studies (REMARK). Nat Clin Pract Urol. 2005;2:416-22. [PMID: 16482653] CrossrefMedlineGoogle Scholar6. Kyzas PA, Denaxa-Kyza D, Ioannidis JP. Almost all articles on cancer prognostic markers report statistically significant results. Eur J Cancer. 2007;43:2559-79. [PMID: 17981458] CrossrefMedlineGoogle Scholar7. Tzoulaki I, Liberopoulos G, Ioannidis JP. Assessment of claims of improved prediction beyond the Framingham risk score. JAMA. 2009;302:2345-52. [PMID: 19952321] CrossrefMedlineGoogle Scholar8. von Elm E, Egger M. The scandal of poor epidemiological research [Editorial]. BMJ. 2004;329:868-9. [PMID: 15485939] CrossrefMedlineGoogle Scholar9. Simera I, Moher D, Hoey J, Schulz KF, Altman DG. A catalogue of reporting guidelines for health research. Eur J Clin Invest. 2010;40:35-53. [PMID: 20055895] CrossrefMedlineGoogle Scholar10. von Elm E, Altman DG, Egger M, Pocock SJ, Gøtzsche PC, Vandenbroucke JP; STROBE Initiative. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies. PLoS Med. 2007;4:296. [PMID: 17941714] CrossrefMedlineGoogle Scholar11. Little J, Higgins JP, Ioannidis JP, Moher D, Gagnon F, von Elm E, et al; STrengthening the REporting of Genetic Association Studies. STrengthening the REporting of Genetic Association Studies (STREGA): an extension of the STROBE statement. PLoS Med. 2009;6:22. [PMID: 19192942] CrossrefMedlineGoogle Scholar12. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, et al; Standards for Reporting of Diagnostic Accuracy. Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative. BMJ. 2003;326:41-4. [PMID: 12511463] CrossrefMedlineGoogle Scholar13. Janssens AC, van Duijn CM. Genome-based prediction of common diseases: methodological considerations for future research. Genome Med. 2009;1:20. [PMID: 19341491] CrossrefMedlineGoogle Scholar14. Khoury MJ, Gwinn M, Ioannidis JP. The emergence of translational epidemiology: from scientific discovery to population health impact. Am J Epidemiol. 2010;172:517-24. [PMID: 20688899] CrossrefMedlineGoogle Scholar15. Moons KG, Altman DG, Vergouwe Y, Royston P. Prognosis and prognostic research: application and impact of prognostic models in clinical practice. BMJ. 2009;338:b606. [PMID: 19502216] CrossrefMedlineGoogle Scholar16. Khoury MJ, Dorman JS. The Human Genome Epidemiology Network [Editorial]. Am J Epidemiol. 1998;148:1-3. [PMID: 9663396] CrossrefMedlineGoogle Scholar17. Freedman AN, Seminara D, Gail MH, Hartge P, Colditz GA, Ballard-Barbash R, et al. Cancer risk prediction models: a workshop on development, evaluation, and application. J Natl Cancer Inst. 2005;97:715-23. [PMID: 15900041] CrossrefMedlineGoogle Scholar18. Altman DG, Schulz KF, Moher D, Egger M, Davidoff F, Elbourne D, et al; CONSORT GROUP (Consolidated Standards of Reporting Trials). The revised CONSORT statement for reporting randomized trials: explanation and elaboration. Ann Intern Med. 2001;134:663-94. [PMID: 11304107] LinkGoogle Scholar19. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, et al; Standards for Reporting of Diagnostic Accuracy. The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration. Ann Intern Med. 2003;138:W1-12. [PMID: 12513067] LinkGoogle Scholar20. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. PLoS Med. 2009;6:1000100. [PMID: 19621070] CrossrefMedlineGoogle Scholar21. Vandenbroucke JP, von Elm E, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, et al; STROBE Initiative. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration. PLoS Med. 2007;4:297. [PMID: 17941715] CrossrefMedlineGoogle Scholar22. Vandenbroucke JP. STREGA, STROBE, STARD, SQUIRE, MOOSE, PRISMA, GNOSIS, TREND, ORION, COREQ, QUOROM, REMARK … and CONSORT: for whom does the guideline toll? J Clin Epidemiol. 2009;62:594-6. [PMID: 19181482] CrossrefMedlineGoogle Scholar23. Cook NR. Use and misuse of the receiver operating characteristic curve in risk prediction. Circulation. 2007;115:928-35. [PMID: 17309939] CrossrefMedlineGoogle Scholar24. Pencina MJ, D'Agostino RB, D'Agostino RB, Vasan RS. Evaluating the added predictive ability of a new marker: from area under the ROC curve to reclassification and beyond. Stat Med. 2008;27:157-72. [PMID: 17569110] CrossrefMedlineGoogle Scholar25. Janssens AC, Khoury MJ. Assessment of improved prediction beyond traditional risk factors: when does a difference make a difference? [Editorial]. Circ Cardiovasc Genet. 2010;3:3-5. [PMID: 20160189] CrossrefMedlineGoogle ScholarAppendix: Members of the GRIPS GroupA. Cecile J.W. Janssens, John P.A. Ioannidis, Sara Bedrosian, Paolo Boffetta, Siobhan M. Dolan, Nicole Dowling, Isabel Fortier, Andrew N. Freedman, Jeremy M. Grimshaw, Jeffrey Gulcher, Marta Gwinn, Mark A. Hlatky, Holly Janes, Peter Kraft, Stephanie Melillo, Christopher J. O'Donnell, Michael J. Pencina, David Ransohoff, Sheri D. Schully, Daniela Seminara, Deborah M. Winn, Caroline F. Wright, Cornelia M. van Duijn, Julian Little, and Muin J. Khoury. Comments0 CommentsSign In to Submit A Comment Author, Article, and Disclosure InformationAffiliations: From Erasmus University Medical Center, Rotterdam, the Netherlands; University of Ioannina School of Medicine and Biomedical Research Institute, Ioannina, Greece; Tufts University School of Medicine, Boston, Massachusetts; Stanford University School of Medicine, Stanford, California; University of Ottawa, Ottawa, Ontario, Canada; and Centers for Disease Control and Prevention, Atlanta, Georgia.Disclaimer: The opinions, findings, and conclusions expressed here are those of the authors and do not reflect the views of the Department of Health and Human Services or represent the official position or policies of the Tufts Clinical and Translational Science Institute.Grant Support: The Centers for Disease Control and Prevention sponsored the workshop on behalf of the Human Genome Epidemiology Network. Dr. Janssens is supported by grants from Erasmus University Medical Center, the Center for Medical Systems Biology in the framework of the Netherlands Genomics Initiative, and the VIDI grant of the Netherlands Organisation for Scientific Research. Dr. Ioannidis is supported by Tufts Clinical and Translational Science Institute, which is supported by the National Institutes of Health, National Center for Research Resources (UL1 RR025752). Dr. Little holds a Canada Research Chair in Human Genome Epidemiology. The funding sources had no role in the study design, data collection, analysis, preparation of the manuscript, or decision to submit the manuscript for publication.Disclosures: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M10-2517.Corresponding Author: A. Cecile J.W. Janssens, PhD, Department of Epidemiology, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands; e-mail, a.[email protected]nl.Current Author Addresses: Drs. Janssens and van Duijn: Department of Epidemiology, Erasmus University Medical Center, PO Box 2040, 3000 CA Rotterdam, the Netherlands.Dr. Ioannidis: Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece.Dr. Little: Department of Epidemiology and Community Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario K1H 8M5, Canada.Dr. Khoury: Office of Public Health Genomics, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30333.Author Contributions: Conception and design: A.C.J.W. Janssens, J.P.A. Ioannidis, C.M. van Duijn, J. Little, M.J. Khoury.Analysis and interpretation of the data: A.C.J.W. Janssens, J.P.A. Ioannidis, C.M. van Duijn, J. Little, M.J. Khoury.Drafting of the article: A.C.J.W. Janssens, J.P.A. Ioannidis, C.M. van Duijn, M.J. Khoury.Critical revision of the article for important intellectual content: A.C.J.W. Janssens, J.P.A. Ioannidis, C.M. van Duijn, J. Little, M.J. Khoury.Final approval of the article: A.C.J.W. Janssens, J.P.A. Ioannidis, J. Little, M.J. Khoury.Statistical expertise: J.P.A. Ioannidis.Obtaining of funding: M.J. Khoury.Administrative, technical, or logistic support: M.J. Khoury.* For members of the GRIPS (Genetic RIsk Prediction Studies) Group, see the Appendix. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited ByNew Framework Developed for Polygenic Risk Score ReportingDevelopment and Validation of a Clinical-Genetic Risk Score to Predict Hepatic Encephalopathy in Patients With Liver CirrhosisCerebrospinal Fluid Cortisol Mediates Brain-Derived Neurotrophic Factor Relationships to Mortality after Severe TBI: A Prospective Cohort StudyPrediction of Melanoma Risk in a Southern European Population Based on a Weighted Genetic Risk ScoreAre Genetic Tests for Atherosclerosis Ready for Routine Clinical Use?Non-HLA genomics: does it have a role in predicting haematopoietic stem cell transplantation outcome?Net Reclassification Improvement: Computation, Interpretation, and Controversies A Literature Review and Clinician's GuideMaarten J.G. Leening, MD, MSc, Moniek M. Vedder, MSc, Jacqueline C.M. Witteman, PhD, Michael J. Pencina, PhD, and Ewout W. Steyerberg, PhDPredicting Risk of Type 2 Diabetes Mellitus with Genetic Risk Models on the Basis of Established Genome-wide Association Markers: A Systematic ReviewAdded value of novel circulating and genetic biomarkers in type 2 diabetes prediction: A systematic reviewRisk in complex genetics: "All models are wrong but some are useful"A predictive model of treatment outcome in patients with chronic HCV infection using IL28B and PD-1 genotypingIs Genetic testing useful to predict type 2 diabetes?Genetic determinants of von Willebrand factor plasma levels and the risk of stroke: the Rotterdam StudyGenetic epidemiology with a Capital E, ten years after 15 March 2011Volume 154, Issue 6Page: 421-425KeywordsClinical geneticsEpidemiological statisticsEpidemiologyGenetic diseasesGeneticsHand strengthHealth careMolecular epidemiologyPrevention, policy, and public healthResearch reporting guidelines ePublished: 15 March 2011 Issue Published: 15 March 2011 PDF DownloadLoading ...