BMJ  2003;327:557-560 (6 September), doi:10.1136/bmj.327.7414.557

Education and debate

Measuring inconsistency in meta-analyses

¹ MRC Biostatistics Unit, Institute of Public Health, Cambridge CB2 2SR, ² Cancer Research UK/NHS Centre for Statistics in Medicine, Institute of Health Sciences, Oxford OX3 7LF

Cochrane Reviews have recently started including the quantity I² to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice?

Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.¹ Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I², which we believe gives a better measure of the consistency between trials in a meta-analysis.

Assessment of the consistency of effects across studies is an essential part of . . . [Full text of this article]

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

This article has been cited by other articles:

• Soon, Y. Y., Stockler, M. R., Askie, L. M., Boyer, M. J. (2009). Duration of Chemotherapy for Advanced Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Trials. JCO 27: 3277-3283 [Abstract] [Full text]  
• Wills, A. -M., Cronin, S., Slowik, A., Kasperaviciute, D., Van Es, M. A., Morahan, J. M., Valdmanis, P. N., Meininger, V., Melki, J., Shaw, C. E., Rouleau, G. A., Fisher, E.M.C., Shaw, P. J., Morrison, K. E., Pamphlett, R., Van den Berg, L. H., Figlewicz, D. A., Andersen, P. M., Al-Chalabi, A., Hardiman, O., Purcell, S., Landers, J. E., Brown, R. H. Jr (2009). A large-scale international meta-analysis of paraoxonase gene polymorphisms in sporadic ALS. Neurology 73: 16-24 [Abstract] [Full text]  
• Vouloumanou, E. K., Karageorgopoulos, D. E., Kazantzi, M. S., Kapaskelis, A. M., Falagas, M. E. (2009). Antibiotics versus placebo or watchful waiting for acute otitis media: a meta-analysis of randomized controlled trials. J Antimicrob Chemother 64: 16-24 [Abstract] [Full text]  
• van Dalen, E. C., Kremer, L. C. M. (2009). Employment Status Among Cancer Survivors. JAMA 302: 33-34 [Full text]  
• Gandhi, R., Tsvetkov, D., Davey, J. R., Mahomed, N. N. (2009). Survival and clinical function of cemented and uncemented prostheses in total knee replacement: A META-ANALYSIS. J Bone Joint Surg Br 91-B: 889-895 [Abstract] [Full text]  
• Gardener, H., Spiegelman, D., Buka, S. L. (2009). Prenatal risk factors for autism: comprehensive meta-analysis. Br. J. Psychiatry 195: 7-14 [Abstract] [Full text]  
• Hooper, L., Ryder, J.J., Kurzer, M.S., Lampe, J.W., Messina, M.J., Phipps, W.R., Cassidy, A. (2009). Effects of soy protein and isoflavones on circulating hormone concentrations in pre- and post-menopausal women: a systematic review and meta-analysis. Hum Reprod Update 15: 423-440 [Abstract] [Full text]  
• Knaup, C., Koesters, M., Schoefer, D., Becker, T., Puschner, B. (2009). Effect of feedback of treatment outcome in specialist mental healthcare: meta-analysis. Br. J. Psychiatry 195: 15-22 [Abstract] [Full text]  
• Ziakas, P. D., Karsaliakos, P., Mylonakis, E. (2009). Effect of prophylactic lamivudine for chemotherapy-associated hepatitis B reactivation in lymphoma: a meta-analysis of published clinical trials and a decision tree addressing prolonged prophylaxis and maintenance. haematol 94: 998-1005 [Abstract] [Full text]  
• Puskarich, M. A., Runyon, M. S., Trzeciak, S., Kline, J. A., Jones, A. E. (2009). Effect of Glucose-Insulin-Potassium Infusion on Mortality in Critical Care Settings: A Systematic Review and Meta-Analysis. J Clin Pharmacol 49: 758-767 [Abstract] [Full text]  
• Wevers, L., van de Port, I., Vermue, M., Mead, G., Kwakkel, G. (2009). Effects of Task-Oriented Circuit Class Training on Walking Competency After Stroke: A Systematic Review. Stroke 40: 2450-2459 [Abstract] [Full text]  
• Brugts, J J, Yetgin, T, Hoeks, S E, Gotto, A M, Shepherd, J, Westendorp, R G J, de Craen, A J M, Knopp, R H, Nakamura, H, Ridker, P, van Domburg, R, Deckers, J W (2009). The benefits of statins in people without established cardiovascular disease but with cardiovascular risk factors: meta-analysis of randomised controlled trials. BMJ 338: b2376-b2376 [Abstract] [Full text]  
• Kirtane, A. J., Gupta, A., Iyengar, S., Moses, J. W., Leon, M. B., Applegate, R., Brodie, B., Hannan, E., Harjai, K., Jensen, L. O., Park, S.-J., Perry, R., Racz, M., Saia, F., Tu, J. V., Waksman, R., Lansky, A. J., Mehran, R., Stone, G. W. (2009). Safety and Efficacy of Drug-Eluting and Bare Metal Stents: Comprehensive Meta-Analysis of Randomized Trials and Observational Studies. Circulation 119: 3198-3206 [Abstract] [Full text]  
• Segal, J. B., Brotman, D. J., Necochea, A. J., Emadi, A., Samal, L., Wilson, L. M., Crim, M. T., Bass, E. B. (2009). Predictive Value of Factor V Leiden and Prothrombin G20210A in Adults With Venous Thromboembolism and in Family Members of Those With a Mutation: A Systematic Review. JAMA 301: 2472-2485 [Abstract] [Full text]  
• Harder, T., Roepke, K., Diller, N., Stechling, Y., Dudenhausen, J. W., Plagemann, A. (2009). Birth Weight, Early Weight Gain, and Subsequent Risk of Type 1 Diabetes: Systematic Review and Meta-Analysis. Am J Epidemiol 169: 1428-1436 [Abstract] [Full text]  
• McAlister, F. A., Wiebe, N., Ezekowitz, J. A., Leung, A. A., Armstrong, P. W. (2009). Meta-analysis: {beta}-Blocker Dose, Heart Rate Reduction, and Death in Patients With Heart Failure. ANN INTERN MED 150: 784-794 [Abstract] [Full text]  
• Al-Jewair, T. S., Azarpazhooh, A., Suri, S., Shah, P. S. (2009). Computer-Assisted Learning in Orthodontic Education: A Systematic Review and Meta-Analysis. J Dent Educ 73: 730-739 [Abstract] [Full text]  
• Kelley, G. A., Kelley, K. S., Hootman, J. M., Jones, D. L. (2009). Exercise and Health-Related Quality of Life in Older Community-Dwelling Adults: A Meta-Analysis of Randomized Controlled Trials. Journal of Applied Gerontology 28: 369-394 [Abstract]  
• Lowndes, S., Khanna, A., Emery, D., Sim, J., Maffulli, N. (2009). Management of unstable slipped upper femoral epiphysis: a meta-analysis. Br Med Bull 90: 133-146 [Abstract] [Full text]  
• Charytan, D. M., Wallentin, L., Lagerqvist, B., Spacek, R., De Winter, R. J., Stern, N. M., Braunwald, E., Cannon, C. P., Choudhry, N. K. (2009). Early Angiography in Patients with Chronic Kidney Disease: A Collaborative Systematic Review. CJASN 4: 1032-1043 [Abstract] [Full text]  
• Freathy, R. M., Bennett, A. J., Ring, S. M., Shields, B., Groves, C. J., Timpson, N. J., Weedon, M. N., Zeggini, E., Lindgren, C. M., Lango, H., Perry, J. R.B., Pouta, A., Ruokonen, A., Hypponen, E., Power, C., Elliott, P., Strachan, D. P., Jarvelin, M.-R., Smith, G. D., McCarthy, M. I., Frayling, T. M., Hattersley, A. T. (2009). Type 2 Diabetes Risk Alleles Are Associated With Reduced Size at Birth. Diabetes 58: 1428-1433 [Abstract] [Full text]  
• Paternoster, L., Chen, W., Sudlow, C. L.M. (2009). Genetic Determinants of White Matter Hyperintensities on Brain Scans: A Systematic Assessment of 19 Candidate Gene Polymorphisms in 46 Studies in 19 000 Subjects * Supplemental References. Stroke 40: 2020-2026 [Abstract] [Full text]  
• Dieguez-Gonzalez, R, Calaza, M, Shi, D, Meulenbelt, I, Loughlin, J, Tsezou, A, Dai, J, Malizos, K N, Slagboom, E P, Kloppenburg, M, Chapman, K, Jiang, Q, Kremer, D, Gomez-Reino, J J, Nakajima, N, Ikegawa, S, Gonzalez, A (2009). Testing the druggable endothelial differentiation gene 2 knee osteoarthritis genetic factor for replication in a wide range of sample collections. Ann Rheum Dis 68: 1017-1021 [Abstract] [Full text]  
• Sakzewski, L., Ziviani, J., Boyd, R. (2009). Systematic Review and Meta-analysis of Therapeutic Management of Upper-Limb Dysfunction in Children With Congenital Hemiplegia. Pediatrics 123: e1111-e1122 [Abstract] [Full text]  
• Dentali, F., Squizzato, A., Brivio, L., Appio, L., Campiotti, L., Crowther, M., Grandi, A. M., Ageno, W. (2009). JAK2V617F mutation for the early diagnosis of Ph- myeloproliferative neoplasms in patients with venous thromboembolism: a meta-analysis. Blood 113: 5617-5623 [Abstract] [Full text]  
• Tonelli, M., Hemmelgarn, B., Reiman, T., Manns, B., Reaume, M. N., Lloyd, A., Wiebe, N., Klarenbach, S. (2009). Benefits and harms of erythropoiesis-stimulating agents for anemia related to cancer: a meta-analysis. CMAJ 180: E62-E71 [Abstract] [Full text]  
• Burns, K. E A, Adhikari, N. K J, Keenan, S. P, Meade, M. (2009). Use of non-invasive ventilation to wean critically ill adults off invasive ventilation: meta-analysis and systematic review. BMJ 338: b1574-b1574 [Abstract] [Full text]  
• Kodama, S., Saito, K., Tanaka, S., Maki, M., Yachi, Y., Asumi, M., Sugawara, A., Totsuka, K., Shimano, H., Ohashi, Y., Yamada, N., Sone, H. (2009). Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women: A Meta-analysis. JAMA 301: 2024-2035 [Abstract] [Full text]  
• Scott, L. J., Muglia, P., Kong, X. Q., Guan, W., Flickinger, M., Upmanyu, R., Tozzi, F., Li, J. Z., Burmeister, M., Absher, D., Thompson, R. C., Francks, C., Meng, F., Antoniades, A., Southwick, A. M., Schatzberg, A. F., Bunney, W. E., Barchas, J. D., Jones, E. G., Day, R., Matthews, K., McGuffin, P., Strauss, J. S., Kennedy, J. L., Middleton, L., Roses, A. D., Watson, S. J., Vincent, J. B., Myers, R. M., Farmer, A. E., Akil, H., Burns, D. K., Boehnke, M. (2009). Genome-wide association and meta-analysis of bipolar disorder in individuals of European ancestry. Proc. Natl. Acad. Sci. USA 106: 7501-7506 [Abstract] [Full text]  
• Mazziotti, G., Floriani, I., Bonadonna, S., Torri, V., Chanson, P., Giustina, A. (2009). Effects of Somatostatin Analogs on Glucose Homeostasis: A Metaanalysis of Acromegaly Studies. J. Clin. Endocrinol. Metab. 94: 1500-1508 [Abstract] [Full text]  
• Hammerli, K., Znoj, H., Barth, J. (2009). The efficacy of psychological interventions for infertile patients: a meta-analysis examining mental health and pregnancy rate. Hum Reprod Update 15: 279-295 [Abstract] [Full text]  
• Toulis, K.A., Goulis, D.G., Farmakiotis, D., Georgopoulos, N.A., Katsikis, I., Tarlatzis, B.C., Papadimas, I., Panidis, D. (2009). Adiponectin levels in women with polycystic ovary syndrome: a systematic review and a meta-analysis. Hum Reprod Update 15: 297-307 [Abstract] [Full text]  
• Vinnicombe, S., Pinto Pereira, S. M., McCormack, V. A., Shiel, S., Perry, N., dos Santos Silva, I. M. (2009). Full-Field Digital versus Screen-Film Mammography: Comparison within the UK Breast Screening Program and Systematic Review of Published Data. Radiology 251: 347-358 [Abstract] [Full text]  
• Assiri, A. M., Alasmari, F. A., Zimmerman, V. A., Baddour, L. M., Erwin, P. J., Tleyjeh, I. M. (2009). Corticosteroid Administration and Outcome of Adolescents and Adults With Acute Bacterial Meningitis: A Meta-analysis. Mayo Clin Proc. 84: 403-409 [Abstract] [Full text]  
• Simunovic, N., Sprague, S., Bhandari, M. (2009). Methodological Issues in Systematic Reviews and Meta-Analyses of Observational Studies in Orthopaedic Research. JBJS 91: 87-94 [Abstract] [Full text]  
• Agarwal, R., Sinha, A. D. (2009). Cardiovascular Protection With Antihypertensive Drugs in Dialysis Patients: Systematic Review and Meta-Analysis. Hypertension 53: 860-866 [Abstract] [Full text]  
• O'Meara, S., Tierney, J., Cullum, N., Bland, J M., Franks, P. J, Mole, T., Scriven, M. (2009). Four layer bandage compared with short stretch bandage for venous leg ulcers: systematic review and meta-analysis of randomised controlled trials with data from individual patients. BMJ 338: b1344-b1344 [Abstract] [Full text]  
• Griesdale, D. E.G., de Souza, R. J., van Dam, R. M., Heyland, D. K., Cook, D. J., Malhotra, A., Dhaliwal, R., Henderson, W. R., Chittock, D. R., Finfer, S., Talmor, D. (2009). Intensive insulin therapy and mortality among critically ill patients: a meta-analysis including NICE-SUGAR study data. CMAJ 180: 821-827 [Abstract] [Full text]  
• Ho, K. M., Tan, J. A. (2009). Benefits and Risks of Corticosteroid Prophylaxis in Adult Cardiac Surgery: A Dose-Response Meta-Analysis. Circulation 119: 1853-1866 [Abstract] [Full text]  
• Coory, M. D (2009). Comment on: heterogeneity in meta-analysis should be expected and appropriately quantified. Int J Epidemiol 0: dyp157v1-dyp157 [Full text]  
• Griffin, S. O., Gray, S. K., Malvitz, D. M., Gooch, B. F. (2009). Caries Risk in Formerly Sealed Teeth. Journal of the American Dental Association 140: 415-423 [Abstract] [Full text]  
• Ranucci, M., Balduini, A., Ditta, A., Boncilli, A., Brozzi, S. (2009). A Systematic Review of Biocompatible Cardiopulmonary Bypass Circuits and Clinical Outcome. Ann. Thorac. Surg. 87: 1311-1319 [Abstract] [Full text]  
• Roposch, A., Stohr, K. K., Dobson, M. (2009). The Effect of the Femoral Head Ossific Nucleus in the Treatment of Developmental Dysplasia of the Hip. A Meta-Analysis. JBJS 91: 911-918 [Abstract] [Full text]  
• Rothberg, B. E. G., Bracken, M. B., Rimm, D. L. (2009). Tissue Biomarkers for Prognosis in Cutaneous Melanoma: A Systematic Review and Meta-analysis. JNCI J Natl Cancer Inst 101: 452-474 [Abstract] [Full text]  
• O'Connor, N. R., Tanabe, K. O., Siadaty, M. S., Hauck, F. R. (2009). Pacifiers and Breastfeeding: A Systematic Review. Arch Pediatr Adolesc Med 163: 378-382 [Abstract] [Full text]  
• Fraser, A., Harris, R., Sattar, N., Ebrahim, S., Davey Smith, G., Lawlor, D. A. (2009). Alanine Aminotransferase, {gamma}-Glutamyltransferase, and Incident Diabetes: The British Women's Heart and Health Study and meta-analysis. Diabetes Care 32: 741-750 [Abstract] [Full text]  
• Cote, M. L., Chen, W., Smith, D. W., Benhamou, S., Bouchardy, C., Butkiewicz, D., Fong, K. M., Gene, M., Hirvonen, A., Kiyohara, C., Larsen, J. E., Lin, P., Raaschou-Nielsen, O., Povey, A. C., Reszka, E., Risch, A., Schneider, J., Schwartz, A. G., Sorensen, M., To-Figueras, J., Tokudome, S., Pu, Y., Yang, P., Wenzlaff, A. S., Wikman, H., Taioli, E. (2009). Meta- and Pooled Analysis of GSTP1 Polymorphism and Lung Cancer: A HuGE-GSEC Review. Am J Epidemiol 169: 802-814 [Abstract] [Full text]  
• van Rosse, F., Maat, B., Rademaker, C. M. A., van Vught, A. J., Egberts, A. C. G., Bollen, C. W. (2009). The Effect of Computerized Physician Order Entry on Medication Prescription Errors and Clinical Outcome in Pediatric and Intensive Care: A Systematic Review. Pediatrics 123: 1184-1190 [Abstract] [Full text]  
• Charrois, T. L, Tsuyuki, R. T (2009). Comment: Sensitivity of Patient Outcomes to Pharmacist Interventions. Part III: Systematic Review and Meta-Analysis in Hyperlipidemia Management. The Annals of Pharmacotherapy 43: 793-794 [Full text]  
• Harris, K. C., Kuramoto, L. K., Schulzer, M., Retallack, J. E. (2009). Effect of school-based physical activity interventions on body mass index in children: a meta-analysis. CMAJ 180: 719-726 [Abstract] [Full text]  
• Jacobs, E. T., Ahnen, D. J., Ashbeck, E. L., Baron, J. A., Greenberg, E. R., Lance, P., Lieberman, D. A., McKeown-Eyssen, G., Schatzkin, A., Thompson, P. A., Martinez, M. E. (2009). Association Between Body Mass Index and Colorectal Neoplasia at Follow-Up Colonoscopy: A Pooling Study. Am J Epidemiol 169: 657-666 [Abstract] [Full text]  
• Adabag, A. S., Ishani, A., Bloomfield, H. E., Ngo, A. K., Wilt, T. J. (2009). Efficacy of N-acetylcysteine in preventing renal injury after heart surgery: a systematic review of randomized trials. Eur Heart J 0: ehp053v1-8 [Abstract] [Full text]  
• Feng, Z.-Z., Shi, J., Zhao, X.-W., Xu, Z.-F. (2009). Meta-analysis of on-pump and off-pump coronary arterial revascularization.. Ann. Thorac. Surg. 87: 757-765 [Abstract] [Full text]  
• Agarwal, R., Brunelli, S. M., Williams, K., Mitchell, M. D., Feldman, H. I., Umscheid, C. A. (2009). Gadolinium-based contrast agents and nephrogenic systemic fibrosis: a systematic review and meta-analysis. Nephrol Dial Transplant 24: 856-863 [Abstract] [Full text]  
• Stevens, J. R., Taylor, A. M. (2009). Hierarchical Dependence in Meta-Analysis. JOURNAL OF EDUCATIONAL AND BEHAVIORAL STATISTICS 34: 46-73 [Abstract] [Full text]  
• Hua Liu, , Ming Liu, , Wei Li, , Bo Wu, , Zhang, S.-h., Yuan Fang, , Yi Wang, (2009). Association of ACE I/D Gene Polymorphism With Vascular Dementia: A Meta-Analysis. J Geriatr Psychiatry Neurol 22: 10-22 [Abstract]  
• Fatourechi, M. M., Kudva, Y. C., Murad, M. H., Elamin, M. B., Tabini, C. C., Montori, V. M. (2009). Hypoglycemia with Intensive Insulin Therapy: A Systematic Review and Meta-Analyses of Randomized Trials of Continuous Subcutaneous Insulin Infusion Versus Multiple Daily Injections. J. Clin. Endocrinol. Metab. 94: 729-740 [Abstract] [Full text]  
• Yarlagadda, S. G., Coca, S. G., Formica, R. N. Jr, Poggio, E. D., Parikh, C. R. (2009). Association between delayed graft function and allograft and patient survival: a systematic review and meta-analysis. Nephrol Dial Transplant 24: 1039-1047 [Abstract] [Full text]  
• Prince, A. C, Brooks, S. J, Stahl, D., Treasure, J. (2009). Systematic review and meta-analysis of the baseline concentrations and physiologic responses of gut hormones to food in eating disorders. Am. J. Clin. Nutr. 89: 755-765 [Abstract] [Full text]  
• Correll, C. U., Rummel-Kluge, C., Corves, C., Kane, J. M., Leucht, S. (2009). Antipsychotic Combinations vs Monotherapy in Schizophrenia: A Meta-analysis of Randomized Controlled Trials. Schizophr Bull 35: 443-457 [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]  
• Ford, A C, Talley, N J, Schoenfeld, P S, Quigley, E M M, Moayyedi, P (2009). Efficacy of antidepressants and psychological therapies in irritable bowel syndrome: systematic review and meta-analysis. Gut 58: 367-378 [Abstract] [Full text]  
• Abrahams, M. S., Aziz, M. F., Fu, R. F., Horn, J.-L. (2009). Ultrasound guidance compared with electrical neurostimulation for peripheral nerve block: a systematic review and meta-analysis of randomized controlled trials. Br J Anaesth 102: 408-417 [Abstract] [Full text]  
• Navaneethan, S. D., Nigwekar, S. U., Sehgal, A. R., Strippoli, G. F.M. (2009). Aldosterone Antagonists for Preventing the Progression of Chronic Kidney Disease: A Systematic Review and Meta-analysis. CJASN 4: 542-551 [Abstract] [Full text]  
• Bangash, F., Agarwal, R. (2009). Masked Hypertension and White-Coat Hypertension in Chronic Kidney Disease: A Meta-analysis. CJASN 4: 656-664 [Abstract] [Full text]  
• Zintzaras, E., Rodopoulou, P., Sakellaridis, N. (2009). Variants of the Arachidonate 5-Lipoxygenase-Activating Protein (ALOX5AP) Gene and Risk of Stroke: A HuGE Gene-Disease Association Review and Meta-Analysis. Am J Epidemiol 169: 523-532 [Abstract] [Full text]  
• Castro-Rodriguez, J. A., Rodrigo, G. J. (2009). Efficacy of Inhaled Corticosteroids in Infants and Preschoolers With Recurrent Wheezing and Asthma: A Systematic Review With Meta-analysis. Pediatrics 123: e519-e525 [Abstract] [Full text]  
• Honrubia, F, Garcia-Sanchez, J, Polo, V, de la Casa, J M M., Soto, J (2009). Conjunctival hyperaemia with the use of latanoprost versus other prostaglandin analogues in patients with ocular hypertension or glaucoma: a meta-analysis of randomised clinical trials. Br. J. Ophthalmol. 93: 316-321 [Abstract] [Full text]  
• Busse, J. W, Kaur, J., Mollon, B., Bhandari, M., Tornetta, P. third, Schunemann, H. J, Guyatt, G. H (2009). Low intensity pulsed ultrasonography for fractures: systematic review of randomised controlled trials. BMJ 338: b351-b351 [Abstract] [Full text]  
• de Boer, A. G. E. M., Taskila, T., Ojajarvi, A., van Dijk, F. J. H., Verbeek, J. H. A. M. (2009). Cancer Survivors and Unemployment: A Meta-analysis and Meta-regression. JAMA 301: 753-762 [Abstract] [Full text]  
• Vidal, L., Gafter-Gvili, A., Leibovici, L., Dreyling, M., Ghielmini, M., Hsu Schmitz, S.-F., Cohen, A., Shpilberg, O. (2009). Rituximab Maintenance for the Treatment of Patients With Follicular Lymphoma: Systematic Review and Meta-analysis of Randomized Trials. JNCI J Natl Cancer Inst 101: 248-255 [Abstract] [Full text]  
• Cole, B. F., Logan, R. F., Halabi, S., Benamouzig, R., Sandler, R. S., Grainge, M. J., Chaussade, S., Baron, J. A. (2009). Aspirin for the Chemoprevention of Colorectal Adenomas: Meta-analysis of the Randomized Trials. JNCI J Natl Cancer Inst 101: 256-266 [Abstract] [Full text]  
• Singh, S. R. BScPhm MSc, Ahmad, F. MSc, Lal, A. MD PhD, Yu, C. MD MSc, Bai, Z. MD MSc, Bennett, H. BPharm PhD (2009). Efficacy and safety of insulin analogues for the management of diabetes mellitus: a meta-analysis. CMAJ 180: 385-397 [Abstract] [Full text]  
• Stothard, K. J., Tennant, P. W. G., Bell, R., Rankin, J. (2009). Maternal Overweight and Obesity and the Risk of Congenital Anomalies: A Systematic Review and Meta-analysis. JAMA 301: 636-650 [Abstract] [Full text]  
• Singh, S., Amin, A. V., Loke, Y. K. (2009). Long-term Use of Inhaled Corticosteroids and the Risk of Pneumonia in Chronic Obstructive Pulmonary Disease: A Meta-analysis. Arch Intern Med 169: 219-229 [Abstract] [Full text]  
• Stasi, R., Sarpatwari, A., Segal, J. B., Osborn, J., Evangelista, M. L., Cooper, N., Provan, D., Newland, A., Amadori, S., Bussel, J. B. (2009). Effects of eradication of Helicobacter pylori infection in patients with immune thrombocytopenic purpura: a systematic review. Blood 113: 1231-1240 [Abstract] [Full text]  
• Barbui, C. MD, Esposito, E. MD, Cipriani, A. MD (2009). Selective serotonin reuptake inhibitors and risk of suicide: a systematic review of observational studies. CMAJ 180: 291-297 [Abstract] [Full text]  
• van der Hilst, C. S., IJtsma, A. J. C., Slooff, M. J. H., TenVergert, E. M. (2009). Cost of Liver Transplantation: A Systematic Review and Meta-Analysis Comparing the United States With Other OECD Countries. Med Care Res Rev 66: 3-22 [Abstract]  
• Mulholland, H. G, Murray, L. J, Cardwell, C. R, Cantwell, M. M (2009). Glycemic index, glycemic load, and risk of digestive tract neoplasms: a systematic review and meta-analysis. Am. J. Clin. Nutr. 89: 568-576 [Abstract] [Full text]  
• Anand, S. S., Xie, C., Pare, G., Montpetit, A., Rangarajan, S., McQueen, M. J., Cordell, H. J., Keavney, B., Yusuf, S., Hudson, T. J., Engert, J. C., on Behalf of the INTERHEART Investigators, (2009). Genetic Variants Associated With Myocardial Infarction Risk Factors in Over 8000 Individuals From Five Ethnic Groups: The INTERHEART Genetics Study. Circ Cardiovasc Genet 2: 16-25 [Abstract] [Full text]  
• Nigwekar, S. U., Navaneethan, S. D., Parikh, C. R., Hix, J. K. (2009). Atrial Natriuretic Peptide for Management of Acute Kidney Injury: A Systematic Review and Meta-analysis. CJASN 4: 261-272 [Abstract] [Full text]  
• Falk, G., Fahey, T. (2009). C-reactive protein and community-acquired pneumonia in ambulatory care: systematic review of diagnostic accuracy studies. Fam Pract 26: 10-21 [Abstract] [Full text]  
• Nevis, I. F., Mathew, A., Novick, R. J., Parikh, C. R., Devereaux, P. J., Natarajan, M. K., Iansavichus, A. V., Cuerden, M. S., Garg, A. X. (2009). Optimal Method of Coronary Revascularization in Patients Receiving Dialysis: Systematic Review. CJASN 4: 369-378 [Abstract] [Full text]  
• Chartapisak, W, Opastiraku, S L, Willis, N S, Craig, J C, Hodson, E M (2009). Prevention and treatment of renal disease in Henoch-Schonlein purpura: a systematic review. Arch. Dis. Child. 94: 132-137 [Abstract] [Full text]  
• Met, R., Bipat, S., Legemate, D. A., Reekers, J. A., Koelemay, M. J. W. (2009). Diagnostic Performance of Computed Tomography Angiography in Peripheral Arterial Disease: A Systematic Review and Meta-analysis. JAMA 301: 415-424 [Abstract] [Full text]  
• Munafo, M. R., Timpson, N. J., David, S. P., Ebrahim, S., Lawlor, D. A. (2009). Association of the DRD2 gene Taq1A polymorphism and smoking behavior: a meta-analysis and new data. Nicotine Tob Res 0: ntn012v1-ntn012 [Abstract] [Full text]  

Rapid Responses:

Read all Rapid Responses

I2 Is Subject to the Same Statistical Power Problems as Cochran's Q

Tania Huedo-Medina, et al.
bmj.com, 4 Jan 2007 [Full text]

A better method of dealing with inconsistency in meta-analyses

Suhail Doi
bmj.com, 4 Jan 2008 [Full text]