Editorials

Meta-analysis and the meta-epidemiology of clinical research

This week's BMJ contains a pot-pourri of materials that deal with the research methodology of meta-analysis. Meta-analysis in clinical research is based on simple principles: systematically searching out, and, when possible, quantitatively combining the results of all studies that have addressed a similar research question. Given the information explosion in clinical research, the logic of basing research reviews on systematic searching and careful quantitative compilation of study results is incontrovertible. However, one aspect of meta-analysis as applied to randomised trials has always been controversial^{1 2} —combining data from multiple studies into single estimates of treatment effect.

In theory, aggregation of data from multiple trials should enhance the precision and accuracy of any pooled result. But combining data requires a leap of faith: it presumes that the differences among studies are primarily due to chance. In fact, differences in the direction or size of treatment effects may be caused by other factors, . . . [Full text of this article]

Publication bias
What is a negative trial?
Data excess
A magic method?

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

Relevant Articles

Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study

Lesley Wood, Matthias Egger, Lise Lotte Gluud, Kenneth F Schulz, Peter Jüni, Douglas G Altman, Christian Gluud, Richard M Martin, Anthony J G Wood, and Jonathan A C Sterne
BMJ 2008 336: 601-605. [Abstract] [Full Text] [PDF]

Test meta-analyses for stability

C David Naylor and George Davey Smith
BMJ 1998 317: 206. [Extract] [Full Text]

Meta-analysis and the meta-epidemiology of clinical research

Desmond Julian, Jacques Le Lorier, and Geneviève Grégoire
BMJ 1998 316: 311. [Extract] [Full Text]

This article has been cited by other articles:

• (2009). Understanding statistical terms: 5 - systematic reviews and meta-analyses. DTB 47: 95-96 [Abstract] [Full text]  
• O'Donoghue, M., Boden, W. E., Braunwald, E., Cannon, C. P., Clayton, T. C., de Winter, R. J., Fox, K. A. A., Lagerqvist, B., McCullough, P. A., Murphy, S. A., Spacek, R., Swahn, E., Wallentin, L., Windhausen, F., Sabatine, M. S. (2008). Early Invasive vs Conservative Treatment Strategies in Women and Men With Unstable Angina and Non-ST-Segment Elevation Myocardial Infarction: A Meta-analysis. JAMA 300: 71-80 [Abstract] [Full text]  
• Wood, L., Egger, M., Gluud, L. L., Schulz, K. F, Juni, P., Altman, D. G, Gluud, C., Martin, R. M, Wood, A. J G, Sterne, J. A C (2008). Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ 336: 601-605 [Abstract] [Full text]  
• Cruciani, M., Lipsky, B. A., Mengoli, C., de Lalla, F. (2005). Are Granulocyte Colony-Stimulating Factors Beneficial in Treating Diabetic Foot Infections?: A meta-analysis. Diabetes Care 28: 454-460 [Abstract] [Full text]  
• Bhandari, M., Bajammal, S., Guyatt, G. H., Griffith, L., Busse, J. W., Schunemann, H., Einhorn, T. A. (2005). Effect of Bisphosphonates on Periprosthetic Bone Mineral Density After Total Joint Arthroplasty. A Meta-Analysis. JBJS 87: 293-301 [Abstract] [Full text]  
• Marks, R.G. (2004). The Future of Web-based Clinical Research in Dentistry. JDR 83: C25-C28 [Abstract] [Full text]  
• McPherson, K., Hemminki, E. (2004). Synthesising licensing data to assess drug safety. BMJ 328: 518-520 [Full text]  
• Clarfield, A. M. (2003). The Decreasing Prevalence of Reversible Dementias: An Updated Meta-analysis. Arch Intern Med 163: 2219-2229 [Abstract] [Full text]  
• Sackett, D. L. (2002). The arrogance of preventive medicine. CMAJ 167: 363-364 [Full text]  
• West, A F, West, R R (2002). Clinical decision-making: coping with uncertainty. Postgrad. Med. J. 78: 319-321 [Full text]  
• Egger, M., Ebrahim, S., Smith, G. D. (2002). Where now for meta-analysis?. Int J Epidemiol 31: 1-5 [Full text]  
• Lewis, S., Baird, P., Evans, R. G., Ghali, W. A., Wright, C. J., Gibson, E., Baylis, F. (2001). Dancing with the porcupine: rules for governing the university-industry relationship. CMAJ 165: 783-785 [Full text]  
• Arriagada, R., Pignon, J.-P. (2000). Is Meta-analysis a Metaphysical or a Scientific Method?. Chest 118: 832-834 [Full text]  
• WEST, R R (2000). Evidence based medicine overviews, bulletins, guidelines, and the new consensus. Postgrad. Med. J. 76: 383-389 [Full text]  
• Wright, I. C., Rabe-Hesketh, S., Woodruff, P. W.R., David, A. S., Murray, R. M., Bullmore, E. T. (2000). Meta-Analysis of Regional Brain Volumes in Schizophrenia. Am. J. Psychiatry 157: 16-25 [Abstract] [Full text]  
• Thissen, M. R. T. M., Neumann, M. H. A., Schouten, L. J. (1999). A Systematic Review of Treatment Modalities for Primary Basal Cell Carcinomas. Arch Dermatol 135: 1177-1183 [Abstract] [Full text]  
• Borger, M. A., Fremes, S. E., Weisel, R. D., Cohen, G., Rao, V., Lindsay, T. F., Naylor, C. D. (1999). Coronary bypass and carotid endarterectomy: does a combined approach increase risk? A metaanalysis. Ann. Thorac. Surg. 68: 14-20 [Abstract] [Full text]  
• Sleep, J., Clark, E. (1999). Weighing up the evidence: The contribution of critical literature reviews to the development of practice. Journal of Research in Nursing 4: 306-313 [Abstract]  
• Hull, R. D., Brant, R. F., Pineo, G. F., Stein, P. D., Raskob, G. E., Valentine, K. A. (1999). Preoperative vs Postoperative Initiation of Low-Molecular-Weight Heparin Prophylaxis Against Venous Thromboembolism in Patients Undergoing Elective Hip Replacement. Arch Intern Med 159: 137-141 [Abstract] [Full text]  
• Naylor, C D., Smith, G. D. (1998). Test meta-analyses for stability. BMJ 317: 206b-206 [Full text]  
• Ioannidis, J. P. A., Cappelleri, J. C., Lau, J. (1998). Issues in Comparisons Between Meta-analyses and Large Trials. JAMA 279: 1089-1093 [Abstract] [Full text]  
• Stuck, A. E, Rubenstein, L. Z, Wieland, D., Vandenbroucke, J. P, Irwig, L., Macaskill, P., Berry, G., Glasziou, P., Seagroatt, V., Stratton, I., Egger, M., Smith, G. D., Minder, C., Langhorne, P., Song, F., Gilbody, S. (1998). Bias in meta-analysis detected by a simple, graphical test. BMJ 316: 469-469 [Full text]  
• Julian, D., Le Lorier, J., Grégoire, G. (1998). Meta-analysis and the meta-epidemiology of clinical research. BMJ 316: 311b-311 [Full text]  
• Ioannidis, J. P. A., Lau, J. (2001). Evolution of treatment effects over time: Empirical insight from recursive cumulative metaanalyses. Proc. Natl. Acad. Sci. USA 98: 831-836 [Abstract] [Full text]