Hostname: page-component-6d856f89d9-8l2sj Total loading time: 0 Render date: 2024-07-16T07:46:13.714Z Has data issue: false hasContentIssue false
  • English
  • Français

Bias in the Analysis and Reporting of Randomized Controlled Trials

Published online by Cambridge University Press:  10 March 2009

Lesley A. Stewart  and
Mahesh K. B. Parmar
Lesley A. Stewart
Affiliation:
MRC Cancer Trials Office
Mahesh K. B. Parmar
Affiliation:
MRC Cancer Trials Office
Get access Rights & Permissions [Opens in a new window]

Abstract

The most reliable information on any type of medical intervention is provided by the results of randomized clinical trials (RCTs). In response to increasing pressure to make effective use of limited resources, increasing numbers of health professionals rely on the medical literature, in particular reports of RCTs. However, RCTs may be influenced by a number of factors that introduce bias during the conduct, analysis, and reporting of the trial. Trials may be described as random, when in fact only quasi-random means of treatment allocation have been used; patients may be selectively removed from the analysis; and the report may restrict presentation to or give undue emphasis to only the analyses that yield positive results. The implications of such bias are discussed with particular reference to the effect that they may have on reviews and meta-analyses.

Type
Special Section: The Quality of the Medical Evidence: Is It Good Enough?
Information
International Journal of Technology Assessment in Health Care , Volume 12 , Issue 2 , Spring 1996 , pp. 264 - 275
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Aboulker, J. P., & Stuart, A. M.Preliminary analysis of the Concorde trial. Lancet, 1993, 341, 889–90.CrossRefGoogle ScholarPubMed
2.Advanced Ovarian Cancer Trialists Group. Chemotherapy in advanced ovarian cancer: An overview of randomised clinical trials. British Medical Journal, 1991, 303, 884–93.CrossRefGoogle Scholar
3.Altman, D. G., & Doré, C.Randomization and baseline comparisons in clinical trials. Lancet, 1990, 335, 149–53.CrossRefGoogle ScholarPubMed
4.Bajorin, D. F., Sarosdy, M. F., Bosl, G. J., et al. A randomised trial of etoposide and carboplatin vs etoposide and cisplatin patients with metastatic germ cell tumours. Proceedings of the American Society of Clinical Oncology, 1991, 10, A535.Google Scholar
5.Bajorin, D. F., Sarosdy, M. F., Pfister, D. G., et al. Randomised trial of etoposide and cisplatin versus etoposide and carboplatin in patients with good-risk germ cell tumours: A multi-institutional study. Journal of Clinical Oncology, 1993, 11, 598–606.CrossRefGoogle Scholar
6.Chalmers, I.The Cochrane collaboration: Preparing, maintaining and disseminating systemic reviews of the effects of health care. Annals of the New York Academy of Science, 1993, 703, 156–65.CrossRefGoogle Scholar
7.Chalmers, T. C., Smith, H. Jr., Blackburn, B., et al. A method for assessing the quality of a randomised controlled trial. Controlled Clinical Trials, 1981, 2, 31–49.CrossRefGoogle Scholar
8.Collins, R., Grey, R., Godwin, J., & Peto, R.Avoidance of large biases and large random errors in the assessment of moderation treatment effects: The need for systematic overview. Statistics in Medicine, 1987, 6, 245–50.CrossRefGoogle Scholar
9.Dickersin, K.Keeping posted. Why register clinical trials? Revisited. Controlled Clinical Trials, 1992, 13, 170–77.CrossRefGoogle Scholar
10.Dickersin, K., & Min, Y. I. NIH clinical trials and publication bias. Online Journal of Current Clinical Trials (serial online), 1993, Doc. No. 50.Google Scholar
11.Dickersin, K., Min, Y. I., & Meinert, C. L.Factors influencing publication of research results. Journal of the American Medical Association, 1992, 267, 374–78.CrossRefGoogle ScholarPubMed
12.Dickersin, K., Scherer, R., & Lefebvre, C.Identification of relevant studies for systematic review. British Medical Journal, 1994, 309, 1286–91.CrossRefGoogle Scholar
13.Dillman, R. O., Seagren, S. L., Propert, K. J., et al. A randomised trial of induction chemotherapy plus high dose radiation versus radiation alone in stage III non-small cell lung cancer. New England Journal of Medicine, 1990, 323, 940–45.CrossRefGoogle ScholarPubMed
14.Easterbrook, P. J., Berlin, J. A., Gopalan, R., & Matthews, D. R.Publication bias in clinical research. Lancet, 1991, 337, 867–72.CrossRefGoogle ScholarPubMed
15. Editorial. On stopping a trial before its time. Lancet, 1993, 342, 1311–12.CrossRefGoogle Scholar
16. Editorial. The placebo effect: Can we use it better? British Medical Journal, 1994, 309, 69–70.CrossRefGoogle Scholar
17.Geller, N. L., & Pocock, S. J.Interim analyses in randomised clinical trials: Ramifications and guidelines for practitioners. Biometrics, 1987, 45, 213–23.CrossRefGoogle Scholar
18.GICOG. Long-term results of a randomised trial comparing cisplatin with cisplatin and cyclophosphamide with cisplatin, cyclophosphamide and adriamycin in advanced ovarian cancer. Gynaecological Oncology, 1992, 45, 115–17.CrossRefGoogle Scholar
19.Green, S. J., Effects on overviews of early stopping rules for clinical trials. Statistics in Medicine, 1987, 6, 361–67.CrossRefGoogle ScholarPubMed
20.Gruppo Intergionale Cooperativo Oncologico Ginecologia. Randomised comparison of cisplatin with cyclophosphamide/cisplatin and with cyclophosphamide/duxorubicin/cisplatin in advanced ovarian cancer. Lancet, 1987, 2, 353–59.Google Scholar
21.Himmel, H. N., Liberati, A., Gelber, R. D., & Chalmers, T. C.Adjuvant chemotherapy for breast cancer: A pooled estimate based on published randomised control trials. Journal of the American Medical Association, 1986, 256, 1148–59.CrossRefGoogle Scholar
22.Hughes, M. D., & Pocock, S. J.Stopping rules and estimation problems in clinical trials. Statistics in Medicine, 1987, 7, 1231–42.CrossRefGoogle Scholar
23.Marsoni, S., Torri, V., Taiana, A., et al. Critical review of quality and development of randomised clinical trials and their influence on the treatment of advanced ovarian cancer. Annals of Oncology, 1990, 1, 343–50.CrossRefGoogle Scholar
24.Nicolucci, A., Grilli, R., Alexanian, A., et al. Quality evolution and clinical implications of randomised controlled clinical trials on the treatment of lung cancer: Lost opportunity for meta-analysis. Journal of the American Medical Association, 1989, 262, 2101–07.CrossRefGoogle ScholarPubMed
25.NSCLCCG. Chemotherapy in non-small cell lung cancer: A meta-analysis using updated individual patient data. Unpublished, 1996.Google Scholar
26.Parmar, M. K. B.Pitfalls and biases in the reporting and interpretation of the results of clinical trials. Lung Cancer, 1994, 10(suppl. 1), 5143–50.CrossRefGoogle ScholarPubMed
27.Peto, R., Mike, M. C., Armitage, P., et al. Design and analysis of randomised clinical trials requiring prolonged observation of each patient: Introduction and design. British Journal of Cancer, 1976, 34, 585–612.CrossRefGoogle ScholarPubMed
28.Pocock, S. J.Clinical trials: A practical approach. New York: John Wiley & Sons, 1990.Google Scholar
29.Shulz, J. F., Chalmers, I., Grimes, D. A., & Altman, D. G.Assessing the quality of randomization from reports of controlled trials published in obstetrics and gynaecology journals. Journal of the American Medical Association, 1994, 272, 125–28.CrossRefGoogle Scholar
30.Simes, S. J.Publication bias: The case for an international registry of clinical trials. Journal of Clinical Oncology, 1986, 41, 1529–41.CrossRefGoogle Scholar
31.Souhami, R. L.The clinical importance of early stopping of randomised trials in cancer treatments. Statistics in Medicine, 1994, 13, 1293–95.CrossRefGoogle ScholarPubMed
32.Stewart, L. A., & Parmar, M. K. B.Meta-analysis of the literature or of individual patient data: Is there a difference? Lancet, 1993, 341, 418–22.CrossRefGoogle ScholarPubMed
33.Volberding, P. A., Lagakos, S. A., Koch, M. A., et al. Zidovudine in asymptomatic human immunodeficiency virus infection. New England Journal of Medicine, 1990, 332, 941–49.CrossRefGoogle Scholar
34.Watney, S. The placebo debate reply. Gay Times, 03 1989.Google Scholar
35.Wright, I. S., Marple, C. D., & Beck, D. F.Report of committee for evaluation of anticoagulants in treatment of coronary thrombosis with myocardial infarction. American Heart Journal, 1948, 36, 801.CrossRefGoogle ScholarPubMed