Trial evidence best informs real-world medicine when it is relevant to the clinical problem
Controlled clinical trials provide the most reliable evidence of whether treatments are effective, particularly when the effects of treatment are moderate. Without such trials, ineffective treatments or, even worse, harmful interventions may be accepted in medical practice. Yet medical practice is often not based on clinical trial evidence, because the evidence is considered not relevant or does not exist. Real-world medicine must not only consider the effectiveness of specific treatments, but must do so in the context of patients who have multiple problems and who are often already receiving many different treatments in a setting different from that tested in the trial.1
The full article is accessible to AMA members and paid subscribers. Login to read more or purchase a subscription now.
Please note: institutional and Research4Life access to the MJA is now provided through Wiley Online Library.
- 1. Dans AL, Dans LF, Guyatt GH, Richardson S. Users' guides to the medical literature: XIV. How to decide on the applicability of trial results to your patient. JAMA 1998; 279: 545-549.
- 2. Simes RJ. Controlled clinical trials. In: Kerr C, Taylor R, Heard G, editors. Handbook of public health methods. Sydney: McGraw Hill, 1997: 130-136.
- 3. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA 2002; 288: 321-333.
- 4. Hennekens CH, Buring JE, Manson JE, et al. Lack of effect of long-term supplementation with beta-carotene on the incidence of malignant neoplasms and cardiovascular disease. N Engl J Med 1996; 334: 1145-1149.
- 5. MRC/BHF Heart Protection Study of antioxidant vitamin supplementation in 20,536 high-risk individuals: a randomised placebo-controlled trial. Lancet 2002; 360: 23-33.
- 6. Moseley JB, O'Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med 2002; 347: 81-88.
- 7. MacMahon S, Collins R. Reliable assessment of the effects of treatment on mortality and major morbidity. II: observational studies. Lancet 2001; 357: 455-462.
- 8. Clinical reality of coronary prevention guidelines: a comparison of EUROASPIRE I and II in nine countries. EUROASPIRE I and II Group. European Action on Secondary Prevention by Intervention to Reduce Events. Lancet 2001; 357: 995-1001.
- 9. Kelly C, Ghazi F, Caldwell K. Psychological distress of cancer and clinical trial participation: a review of the literature. Eur J Cancer 2002; 11: 6-15.
- 10. Celemajer DS. Evidence-based medicine: how good is the evidence? Med J Aust 2001; 174: 293-295.
- 11. Australian Institute of Health and Welfare. Australia's health services expenditure to 1999–00. Health and Welfare Expenditure Series No. 6. Canberra: AIHW, 2001. (AIHW Cat. No. HWE-17.)
- 12. Detsky A. Using cost-effectiveness analysis to improve the efficiency of allocating funds to clinical trials. Stat Med 1990; 9: 173-184.
- 13. Glasziou PP. Support for trials of promising medications through the Pharmaceutical Benefits Scheme. Med J Aust 1995; 162: 33-36.
- 14. Simes RJ, Glasziou PP. Meta-analysis and quality of evidence in the economic evaluation of drug trials. PharmacoEconomics 1992; 1: 282-292.
- 15. Horton R. Time to register randomised trials. Lancet 1999; 354: 1138-1139.
I am grateful to Rhana Pike for editorial assistance and to Martin Stockler and Anthony Keech for helpful advice.