BMJ  2007;335:914-916 (3 November), doi:10.1136/bmj.39343.408449.80

Analysis

Uncertainty in heterogeneity estimates in meta-analyses

Clinical Trials and Evidence-Based Medicine Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina 45110, Greece

John Ioannidis, Nikolaos Patsopoulos, and Evangelos Evangelou argue that, although meta-analyses often measure heterogeneity between studies, these estimates can have large uncertainty, which must be taken into account when interpreting evidence

The first 150 words of the full text of this article appear below.

The extent of between study heterogeneity should be measured when interpreting results of meta-analyses Meta-analyses rarely document uncertainty in estimates of heterogeneity Our evaluation of a large number of meta-analyses shows a wide range of uncertainty about the extent of heterogeneity in most Confidence intervals of I2 should be calculated and considered when interpreting meta-analyses

An important aim of systematic reviews and meta-analyses is to assess the extent to which different studies give similar or dissimilar results.¹ Clinical, methodological, and biological heterogeneity are often topic specific, but statistical heterogeneity can be examined with the same methods in all meta-analyses. Therefore, the perception of statistical heterogeneity or homogeneity often influences meta-analysts and clinicians in important decisions. These decisions include whether the data are similar enough to combine different studies; whether a treatment is applicable to all or should be "individualised" because of variable benefits or harms in different types of patients; . . . [Full text of this article]

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    StumbleUpon    Technorati    What's this?

Relevant Articles

The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration

Alessandro Liberati, Douglas G Altman, Jennifer Tetzlaff, Cynthia Mulrow, Peter C Gøtzsche, John P A Ioannidis, Mike Clarke, P J Devereaux, Jos Kleijnen, and David Moher
BMJ 2009 339: b2700. [Abstract] [Full Text]

Reasons or excuses for avoiding meta-analysis in forest plots

John P A Ioannidis, Nikolaos A Patsopoulos, and Hannah R Rothstein
BMJ 2008 336: 1413-1415. [Extract] [Full Text] [PDF]

Doctors’ versus patients’ global assessments of treatment effectiveness: empirical survey of diverse treatments in clinical trials

Evangelos Evangelou, Georgios Tsianos, and John P A Ioannidis
BMJ 2008 336: 1287-1290. [Abstract] [Full Text] [PDF]

Antithrombin III in critically ill patients

A Torossian, J Graf, and A Bauhofer
BMJ 2007 335: 1219-1220. [Extract] [Full Text] [PDF]

Sedative hypnotics in older people with insomnia: meta-analysis of risks and benefits

Jennifer Glass, Krista L Lanctôt, Nathan Herrmann, Beth A Sproule, and Usoa E Busto
BMJ 2005 331: 1169. [Abstract] [Full Text] [PDF]

Angiotensin receptor blockers and risk of myocardial infarction: systematic review

Michael A McDonald, Scot H Simpson, Justin A Ezekowitz, Gabor Gyenes, and Ross T Tsuyuki
BMJ 2005 331: 873. [Abstract] [Full Text] [PDF]

Tacrolimus versus ciclosporin as primary immunosuppression for kidney transplant recipients: meta-analysis and meta-regression of randomised trial data

Angela C Webster, Rebecca C Woodroffe, Rod S Taylor, Jeremy R Chapman, and Jonathan C Craig
BMJ 2005 331: 810. [Abstract] [Full Text] [PDF]

Effectiveness of innovations in nurse led chronic disease management for patients with chronic obstructive pulmonary disease: systematic review of evidence

Stephanie J C Taylor, Bridget Candy, Rosamund M Bryar, Jean Ramsay, Hubertus J M Vrijhoef, Glenda Esmond, Jadwiga A Wedzicha, and Chris J Griffiths
BMJ 2005 331: 485. [Abstract] [Full Text] [PDF]

How strong is the evidence for the use of perioperative blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials

P J Devereaux, W Scott Beattie, Peter T-L Choi, Neal H Badner, Gordon H Guyatt, Juan C Villar, Claudio S Cinà, Kate Leslie, Michael J Jacka, Victor M Montori, Mohit Bhandari, Alvaro Avezum, Alexandre B Cavalcanti, Julian W Giles, Thomas Schricker, Homer Yang, Carl-Johan Jakobsen, and Salim Yusuf
BMJ 2005 331: 313-321. [Abstract] [Full Text] [PDF]

Treatment of ocular hypertension and open angle glaucoma: meta-analysis of randomised controlled trials

Philip C Maier, Jens Funk, Guido Schwarzer, Gerd Antes, and Yngve T Falck-Ytter
BMJ 2005 331: 134. [Abstract] [Full Text] [PDF]

Psychosocial and psychological interventions for prevention of postnatal depression: systematic review

Cindy-Lee Dennis
BMJ 2005 331: 15. [Abstract] [Full Text] [PDF]

Measuring inconsistency in meta-analyses

Julian P T Higgins, Simon G Thompson, Jonathan J Deeks, and Douglas G Altman
BMJ 2003 327: 557-560. [Extract] [Full Text] [PDF]

Systematic Reviews: Obtaining data from randomised controlled trials: how much do we need for reliable and informative meta-analyses?

M J Clarke and L A Stewart
BMJ 1994 309: 1007-1010. [Extract] [Full Text]

This article has been cited by other articles:

• Taioli, E., Garza, M. A., Ahn, Y. O., Bishop, D. T., Bost, J., Budai, B., Chen, K., Gemignani, F., Keku, T., Lima, C. S. P., Le Marchand, L., Matsuo, K., Moreno, V., Plaschke, J., Pufulete, M., Thomas, S. B., Toffoli, G., Wolf, C. R., Moore, C. G., Little, J. (2009). Meta- and Pooled Analyses of the Methylenetetrahydrofolate Reductase (MTHFR) C677T Polymorphism and Colorectal Cancer: A HuGE-GSEC Review. Am J Epidemiol 170: 1207-1221 [Abstract] [Full text]  
• Richards, J. B., Kavvoura, F. K., Rivadeneira, F., Styrkarsdottir, U., Estrada, K., Halldorsson, B. V., Hsu, Y.-H., Zillikens, M. C., Wilson, S. G., Mullin, B. H., Amin, N., Aulchenko, Y. S., Cupples, L. A., Deloukas, P., Demissie, S., Hofman, A., Kong, A., Karasik, D., van Meurs, J. B., Oostra, B. A., Pols, H. A.P., Sigurdsson, G., Thorsteinsdottir, U., Soranzo, N., Williams, F. M.K., Zhou, Y., Ralston, S. H., Thorleifsson, G., van Duijn, C. M., Kiel, D. P., Stefansson, K., Uitterlinden, A. G., Ioannidis, J. P.A., Spector, T. D., for the GEFOS (Genetic Factors for Osteoporosis) C, (2009). Collaborative Meta-analysis: Associations of 150 Candidate Genes With Osteoporosis and Osteoporotic Fracture. ANN INTERN MED 151: 528-537 [Abstract] [Full text]  
• Srinivasan, M., Taioli, E., C.Ragin, C. (2009). Human papillomavirus type 16 and 18 in primary lung cancers--a meta-analysis. Carcinogenesis 30: 1722-1728 [Abstract] [Full text]  
• Katritsis, D. G., Siontis, G. C.M., Ioannidis, J. P.A. (2009). Double Versus Single Stenting for Coronary Bifurcation Lesions: A Meta-Analysis. Circ Cardiovasc Interv 2: 409-415 [Abstract] [Full text]  
• Liberati, A., Altman, D. G., Tetzlaff, J., Mulrow, C., Gotzsche, P. C., Ioannidis, J. P.A., Clarke, M., Devereaux, P. J., Kleijnen, J., Moher, D. (2009). The PRISMA Statement for Reporting Systematic Reviews and Meta-Analyses of Studies That Evaluate Health Care Interventions: Explanation and Elaboration. ANN INTERN MED 151: W-65-W-94 [Abstract] [Full text]  
• Khoury, M. J., Bertram, L., Boffetta, P., Butterworth, A. S., Chanock, S. J., Dolan, S. M., Fortier, I., Garcia-Closas, M., Gwinn, M., Higgins, J. P. T., Janssens, A. C. J. W., Ostell, J., Owen, R. P., Pagon, R. A., Rebbeck, T. R., Rothman, N., Bernstein, J. L., Burton, P. R., Campbell, H., Chockalingam, A., Furberg, H., Little, J., O'Brien, T. R., Seminara, D., Vineis, P., Winn, D. M., Yu, W., Ioannidis, J. P. A. (2009). Genome-Wide Association Studies, Field Synopses, and the Development of the Knowledge Base on Genetic Variation and Human Diseases. Am J Epidemiol 170: 269-279 [Abstract] [Full text]  
• Clark, A. M., Savard, L. A., Thompson, D. R. (2009). What is the strength of evidence for heart failure disease-management programs?. J Am Coll Cardiol 54: 397-401 [Abstract] [Full text]  
• Liberati, A., Altman, D. G, Tetzlaff, J., Mulrow, C., Gotzsche, P. C, Ioannidis, J. P A, Clarke, M., Devereaux, P J, Kleijnen, J., Moher, D. (2009). The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ 339: b2700-b2700 [Abstract] [Full text]  
• Mol, S. E., Bus, A. G., de Jong, M. T. (2009). Interactive Book Reading in Early Education: A Tool to Stimulate Print Knowledge as Well as Oral Language. REVIEW OF EDUCATIONAL RESEARCH 79: 979-1007 [Abstract] [Full text]  
• Barbui, C., Signoretti, A., Mule, S., Boso, M., Cipriani, A. (2009). Does the Addition of a Second Antipsychotic Drug Improve Clozapine Treatment?. Schizophr Bull 35: 458-468 [Abstract] [Full text]  
• Ioannidis, J. P.A. (2009). Prediction of Cardiovascular Disease Outcomes and Established Cardiovascular Risk Factors by Genome-Wide Association Markers. Circ Cardiovasc Genet 2: 7-15 [Abstract] [Full text]  
• Thorlund, K., Devereaux, P J, Wetterslev, J., Guyatt, G., Ioannidis, J. P A, Thabane, L., Gluud, L.-L., Als-Nielsen, B., Gluud, C. (2009). Can trial sequential monitoring boundaries reduce spurious inferences from meta-analyses?. Int J Epidemiol 38: 276-286 [Abstract] [Full text]  
• Brok, J., Thorlund, K., Wetterslev, J., Gluud, C. (2009). Apparently conclusive meta-analyses may be inconclusive--Trial sequential analysis adjustment of random error risk due to repetitive testing of accumulating data in apparently conclusive neonatal meta-analyses. Int J Epidemiol 38: 287-298 [Abstract] [Full text]  
• Vineis, P., Manuguerra, M., Kavvoura, F. K., Guarrera, S., Allione, A., Rosa, F., Di Gregorio, A., Polidoro, S., Saletta, F., Ioannidis, J. P. A., Matullo, G. (2009). A Field Synopsis on Low-Penetrance Variants in DNA Repair Genes and Cancer Susceptibility. JNCI J Natl Cancer Inst 101: 24-36 [Abstract] [Full text]  
• Loke, Y. K. MBBS MD, Singh, S. MD MPH, Furberg, C. D. MD PhD (2009). Long-term use of thiazolidinediones and fractures in type 2 diabetes: a meta-analysis. CMAJ 180: 32-39 [Abstract] [Full text]  
• Mills, E. J., Rachlis, B., Wu, P., Devereaux, P. J., Arora, P., Perri, D. (2008). Primary Prevention of Cardiovascular Mortality and Events With Statin Treatments A Network Meta-Analysis Involving More Than 65,000 Patients.. J Am Coll Cardiol 52: 1769-1781 [Abstract] [Full text]  
• Patsopoulos, N. A, Evangelou, E., Ioannidis, J. P. (2008). Heterogeneous views on heterogeneity. Int J Epidemiol 0: dyn235v1-dyn235 [Full text]  
• de Bakker, P. I.W., Ferreira, M. A.R., Jia, X., Neale, B. M., Raychaudhuri, S., Voight, B. F. (2008). Practical aspects of imputation-driven meta-analysis of genome-wide association studies. Hum Mol Genet 17: R122-R128 [Abstract] [Full text]  
• Patsopoulos, N. A, Evangelou, E., Ioannidis, J. P. (2008). Sensitivity of between-study heterogeneity in meta-analysis: proposed metrics and empirical evaluation. Int J Epidemiol 37: 1148-1157 [Abstract] [Full text]  
• Higgins, J. P T (2008). Commentary: Heterogeneity in meta-analysis should be expected and appropriately quantified. Int J Epidemiol 37: 1158-1160 [Full text]  
• Ioannidis, J. P A, Patsopoulos, N. A, Rothstein, H. R (2008). Reasons or excuses for avoiding meta-analysis in forest plots. BMJ 336: 1413-1415 [Full text]  
• Evangelou, E., Tsianos, G., Ioannidis, J. P A (2008). Doctors' versus patients' global assessments of treatment effectiveness: empirical survey of diverse treatments in clinical trials. BMJ 336: 1287-1290 [Abstract] [Full text]  
• Clark, W. F., Sontrop, J. M. (2008). What Have We Learned about Optimal Induction Therapy for Lupus Nephritis (III through V) from Randomized, Controlled Trials?. CJASN 3: 895-898 [Full text]  
• Torossian, A, Graf, J, Bauhofer, A (2007). Antithrombin III in critically ill patients. BMJ 335: 1219-1220 [Full text]  

Online poll

Find out more on doc2doc >>