The format in which the results of randomised controlled trials (RCTs) are presented can have a major impact on how they are interpreted, and the extent to which they will be adopted into clinical practice. A key element in the reporting of RCTs is the measurement scale on which outcomes are assessed. Scales which are presented as large whole numbers tend to attract the interest of clinicians and patients, independent of the reliability of the estimates.1,2 Enough information needs to be presented to allow clinicians to convert the size of the reported benefit into a format which allows easy comparison with other relevant trial results, including the range of certainty of the benefit (Box 1).3 As outcomes may be measured and collected in a variety of ways, it is essential that there is prior agreement on how any benefit or detriment of the intervention will be reported.
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. Hux JE, Naylor CD. Communicating the benefits of chronic preventive therapy: does the format of efficacy data determine patients’ acceptance of treatment? Med Decision Making 1995; 15: 152-157.
- 2. Naylor CD, Chen E, Strauss B. Measured enthusiasm: does the method of reporting trial results alter perceptions of therapeutic effectiveness? Ann Intern Med 1992; 117: 916-921.
- 3. Moher D, Schulz KF, Altman DG, et al, for the CONSORT group. The revised CONSORT statement for reporting randomized trials: explanation and elaboration. Ann Intern Med 2001; 134: 663-694.
- 4. Hollander M, Wolfe D. Nonparametric statistical methods. 2nd ed. New York: John Wiley, 1999.
- 5. Shakespeare TP, Gebski VJ, Veness MJ, Simes J. Improving interpretation of clinical studies by use of confidence levels, clinical significance curves, and risk-benefit contours. Lancet 2001; 357: 1349-1353.
- 6. Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S). Lancet 1994; 344: 1383-1389.
- 7. Cook RJ, Sackett DL. The number needed to treat: a clinically useful measure of treatment effect. BMJ 1995; 310: 452-454.
- 8. Heart Protection Study Collaborative Group. MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 5936 high-risk individuals with diabetes: randomised placebo-controlled trial. Lancet 2003; 361: 2005-2016.
- 9. Kirby A, Gebski VJ, Keech AC. Determining the sample size in a clinical trial. Med J Aust 2002; 177: 256-257. <eMJA full text>
None identified.