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Semin Reprod Med 2003; 21(1): 055-064
DOI: 10.1055/s-2003-39995
Copyright © 2003 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel.: +1(212) 584-4662

Randomized Clinical Trials: The Meeting Place of Medical Practice and Clinical Research

Edward G. Hughes
  • Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada
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Publication History

Publication Date:
12 June 2003 (online)

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ABSTRACT

Randomized clinical trials (RCTs) have been used to assess interventions affecting health since biblical times. They provide the most valid means of measuring the true effects of intervention compared with no treatment or placebo. Although they can also be used to assess the value of diagnostic tests, this article focuses on randomized trials in the context of treatment. Key elements of an RCT include: the explicit definition of a clinically relevant question; the identification of an appropriate sample of patients; a clearly defined and reproducible intervention; an appropriate intervention and comparator; clinically relevant, measurable outcomes; and appropriate tools for measurement and analysis. It is also essential to establish that the question posed is ethical, the methods of study are valid, and that follow-up is complete, with an “intent to treat” analysis. Results are best presented using both proportions and absolute numbers. By providing clinical decision-makers with numbers needed to treat or harm, decisions may be better informed and easier to understand, than if proportions alone are used.

KEYWORDS

Randomized controlled trial - random allocation - clinical epidemiology - treatment effectiveness

REFERENCES

  • 1 Chalmers T C. The clinical trial.  Milbank Memorial Fund Quarterly/Health and Society . 1981;  59 324-339
    PubMedGoogle Scholar
  • 2 The Canadian Institute for Advanced Research. The determinants of health. CIAR Publication No. 5, 1991: 1-49
  • 3 Chalmers I. Getting to grips with Archie Cochrane's agenda.  BMJ . 1992;  305 786-787
    PubMedGoogle Scholar
  • 4 Hughes E G, Fedorkow D M, Collins J A. A quantitative overview of controlled trials in endometriosis-associated infertility.  Fertil Steril . 1993;  59 963-970
    PubMedGoogle Scholar
  • 5 Taylor K M, Margolese M D, Soskolne C L. Physician's reasons for not entering eligible patients in a randomized clinical trial of surgery for breast cancer.  N Engl J Med . 1984;  310 1363-1367
    CrossrefPubMedGoogle Scholar
  • 6 Daniel: The young Hebrews at the court of Nebuchadnezzar. Chapter 1, Verse 10. In: Jones A, ed. The Jerusalem Bible. Garden City, NY: Doubleday & Company 1996: 1423
    Google Scholar
  • 7 Thomas D P. Experiment versus authority: James Lind and Benjamin Rush.  N Engl J Med . 1969;  281 932-934
    PubMedGoogle Scholar
  • 8 Medical Research Council. Streptomycin treatment of pulmonary tuberculosis.  Br Med J . 1948;  2 769-782
    CrossrefPubMedGoogle Scholar
  • 9 The Cochrane Database of Systematic Reviews (CDSR). 1st ed. (1.0) Windows.  Oxford: Update Software 1995
    Google Scholar
  • 10 Hughes E G, Beecroft M L, Wilkie V. et al .A multi-centre randomized trial of expectant management versus in-vitro fertilization (EMVI), in women with fallopian tube patency. Canadian Fertility and Andrology Society Annual Meeting; Charlevoix, Quebec, September 25-28, 2002. Abstract TP32
    Google Scholar
  • 11 Hughes E G, Giacomini M. Funding in vitro fertilization treatment for persistent subfertility: the pain and the politics.  Fertil Steril . 2001;  76 431-442
    CrossrefPubMedGoogle Scholar
  • 12 Marcoux S, Maheux R, Berube S, and the Canadian Collaborative Group on Endometriosis. Laparoscopic surgery in infertile women with minimal or mild endometriosis.  N Engl J Med . 1997;  337 217-222
    PubMedGoogle Scholar
  • 13 Hughes E G, Lamont D A, Beecroft M L, Wilson D MC, Brennan B G, Rice S C. Randomized trial of a “stage-of-change” oriented smoking cessation intervention in infertile and pregnant women.  Fertil Steril . 2000;  74 498-503
    CrossrefPubMedGoogle Scholar
  • 14 Hughes E G, Beecroft M L, Lamont D. et al . A randomized controlled trial of a “stage-of-change” smoking cessation intervention for subfertile and pregnant patients [abstract].  Fertil Steril . 1999;  72 (suppl 1) S61-S62
    PubMedGoogle Scholar
  • 15 Daya S. Is there a place for the crossover design in infertility trials?.  Fertil Steril . 1993;  59 6-7
    PubMedGoogle Scholar
  • 16 Roethlisberger F G, Dickson W J, Hawthorne Works C. Management and the Worker: An Account of a Research Program Conducted by the Western Electric Company. Cambridge: Harvard University Press 1946
    Google Scholar
  • 17 Dimond E G, Kittle C F, Crocket J E. Evaluation of internal mammary artery ligation and sham procedure in angina pectoris [abstract].  Circulation . 1958;  18 712
    PubMedGoogle Scholar
  • 18 Chalmers T C, Celano P, Sacks H S, Smith Jr H. Bias in treatment assignment in controlled clinical trials.  N Engl J Med . 1983;  309 1358-1361
    PubMedGoogle Scholar
  • 19 Schulz K F, Chalmers I, Grimes D A, Altman D G. Assessing the quality of randomization from reports of controlled trials published in obstetrics and gynecology journals.  JAMA . 1994;  272 125-128
    CrossrefPubMedGoogle Scholar
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