Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers

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• 作者：Jonathan A Cook (1) (2)
  Jenni Hislop (3)
  Douglas G Altman (1)
  Peter Fayers (4) (5)
  Andrew H Briggs (6)
  Craig R Ramsay (2)
  John D Norrie (7)
  Ian M Harvey (8)
  Brian Buckley (9)
  Dean Fergusson (10)
  Ian Ford (11)
  Luke D Vale (3)
  for the DELTA group
  
  1. Centre for Statistics in Medicine ; Nuffield Department of Orthopaedics ; Rheumatology and Musculoskeletal Sciences ; University of Oxford ; Botnar Research Centre ; Nuffield Orthopaedic Centre ; Windmill Road ; Oxford ; OX3 7LD ; UK
  2. Health Services Research Unit ; University of Aberdeen ; Health Sciences Building ; Foresthill ; Aberdeen ; AB25 2ZD ; UK
  3. Institute of Health and Society ; Newcastle University ; The Baddiley-Clark Building ; Richardson Road ; Newcastle upon Tyne ; NE2 4AX ; UK
  4. Population Health ; University of Aberdeen ; Polwarth Building ; Foresterhill ; Aberdeen ; AB25 2ZD ; UK
  5. Department of Cancer Research and Molecular ; Norwegian University of Science and Technology ; Mailbox 8905 ; Trondheim ; N-7491 ; Norway
  6. Health Economics and Health Technology Assessment ; University of Glasgow ; 1 Lilybank Gardens ; Glasgow ; G12 8RZ ; UK
  7. Centre for Healthcare Randomised Trials (CHaRT) ; University of Aberdeen ; Health Sciences Building ; Aberdeen ; AB25 2ZD ; UK
  8. Faculty of Medicine and Health Sciences ; University of East Anglia ; Elizabeth Fry Building ; Norwich Research Park ; Norwich ; NR4 7TJ ; UK
  9. National University of Ireland ; University Road ; Galway ; Ireland
  10. Clinical Epidemiology Program ; Ottawa Hospital Research Institute ; 725 Parkdale Avenue ; Ottawa ; ON ; K1Y 4E9 ; Canada
  11. Robertson Centre for Biostatistics ; University of Glasgow ; Boyd Orr Building ; University Avenue ; Glasgow ; G12 8QQ ; UK
  
• 关键词：Target difference ; clinically important difference ; sample size ; randomised controlled trial ; guidance
• 刊名：Trials
• 出版年：2015
• 出版时间：December 2015
• 年：2015
• 卷：16
• 期：1
• 全文大小：430 KB
• 参考文献：1. Charles P, Giraudeau B, Dechartres A, Baron G, Ravaud P. Reporting of sample size calculation in randomised controlled trials: review. BMJ. 2009;338:b1732. CrossRef
  2. Julious S. Sample Sizes for Clinical Trials. Boca Raton, FL: Chapman and Hall/CRC Press; 2010.
  3. McDonald A, Knight RC, Campbell MK, Entwistle VA, Grant AM, Cook JA, et al. What influences recruitment to randomised controlled trials? A review of trials funded by two UK funding agencies. Trials. 2006;7:7. CrossRef
  4. Cook JA, Hislop J, Adewuyi TE, Harrild K, Altman DG, Ramsay CR, et al. Assessing methods to specify the targeted difference for a randomised controlled trial 鈥?DELTA (Difference ELicitation in TriAls) review. Health Technol Assess. 2014;18:28. CrossRef
  5. Hislop J, Adewuyi T, Vale LD, Harrild K, Fraser C, Gurung T, et al. Methods for specifying the target difference in a randomised controlled trial: the Difference ELicitation in TriAls (DELTA) systematic review. PLoS Med. 2014;11:e1001645. CrossRef
  6. Hellum C, Johnsen LG, Storheim K, Nygaard OP, Brox JI, Rossvoll I, et al. Surgery with disc prosthesis versus rehabilitation in patients with low back pain and degenerative disc: two year follow-up of randomised study. BMJ. 2011;342:d2786. CrossRef
  7. Lois N, Burr J, Norrie J, Vale L, Cook J, McDonald A, et al. Internal limiting membrane peeling versus no peeling for idiopathic full-thickness macular hole: a pragmatic randomized controlled trial. Invest Ophthalmol Vis Sci. 2011;52:1586鈥?2. CrossRef
  8. Bacchetti P. Current sample size conventions: flaws, harms, and alternatives. BMC Med. 2010;8:17. CrossRef
  9. Clark T, Berger U, Mansmann U. Sample size determinations in original research protocols for randomised clinical trials submitted to UK research ethics committees: review. BMJ. 2013;346:f1135. CrossRef
  10. Friedman LM, Furberg CD, DeMets DL. Fundamentals of Clinical Trials. New York: Springer; 2010. CrossRef
  11. Matthews JN. Introduction to Randomized Controlled Clinical Trials. London: Taylor & Francis; 2006. CrossRef
  12. Peace KE, Chen DG. Clinical Trial Methodology. London: Chapman & Hall; 2010. CrossRef
  13. Pocock SJ. Clinical Trials: A Practical Approach. Chichester: Wiley & Co; 1983.
  14. Fayers PM, Cuschieri A, Fielding J, Craven J, Uscinska B, Freedman L. Sample size calculation for clinical trials: the impact of clinician beliefs. Br J Cancer. 2000;82:213鈥?. CrossRef
  15. Copay AG, Subach BR, Glassman SD, Polly J, Schuler TC. Understanding the minimum clinically important difference: a review of concepts and methods. Spine J. 2007;7:541鈥?. CrossRef
  16. Wells G, Beaton D, Shea B, Boers M, Simon L, Strand V, et al. Minimal clinically important differences: Review of methods. J Rheumatol. 2001;28:406鈥?2.
  17. Beaton DE, Boers M, Wells GA. Many faces of the minimal clinically important difference (MICD): A literature review and directions for future research. Curr Opin Rheumatol. 2002;14:109鈥?4. CrossRef
  18. Hays RD, Woolley JM. The concept of clinically meaningful difference in health-related quality-of-life research. How meaningful is it? Pharmacoeconomics. 2000;18:419鈥?3. CrossRef
  19. Barrett B, Brown D, Mundt M, Brown R. Sufficiently important difference: expanding the framework of clinical significance. Med Decis Making. 2005;25:250鈥?1. CrossRef
  20. Willan AR, Eckermann S. Optimal clinical trial design using value of information methods with imperfect implementation. Health Econ. 2010;19:549鈥?1.
  21. Kikuchi T, Pezeshk H, Gittins J. A Bayesian cost-benefit approach to the determination of sample size in clinical trials. Stat Med. 2008;27:68鈥?2. CrossRef
  22. Blanton H, Jaccard J. Arbitrary metrics in psychology. Am Psychol. 2006;61:27鈥?1. CrossRef
  23. Carragee EJ. The rise and fall of the 鈥渕inimum clinically important difference鈥? Spine J. 2010;10:283鈥?. CrossRef
  24. Van TM, Malmivaara A, Hayden J, Koes B. Statistical significance versus clinical importance: trials on exercise therapy for chronic low back pain as example. Spine. 2007;32:1785鈥?0. CrossRef
  25. Altman DG, Schulz KF, Moher D, Egger M, Davidoff F, Elbourne D, et al. The revised CONSORT statement for reporting randomized trials: explanation and elaboration. Ann Intern Med. 2001;134:663鈥?4. CrossRef
  26. Schulz KF, Altman DG, Moher D, CONSORT Group. CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials. BMJ. 2010;340:c332. CrossRef
  27. Chan AW, Tetzlaff JM, Altman DG, Laupacis A, Gotzsche PC, Krle啪a-Jeri膰 K, et al. SPIRIT 2013 statement: defining standard protocol items for clinical trials. Ann Intern Med. 2013;158:200鈥?. CrossRef
  28. Glazener C, Boachie C, Buckley B, Cochran C, Dorey G, Grant A, et al. Urinary incontinence in men after formal one-to-one pelvic-floor muscle training following radical prostatectomy or transurethral resection of the prostate (MAPS): two parallel randomised controlled trials. Lancet. 2011;378:328鈥?7. CrossRef
  29. Hunter KF, Moore KN, Glazener CM. Conservative management for postprostatectomy urinary incontinence. Cochrane Database Syst Rev. 2007;2:CD001843.
  30. Brooks Jr HL. Macular hole surgery with and without internal limiting membrane peeling. Ophthalmology. 2000;107:1939鈥?8. CrossRef
  31. Paques M, Chastang C, Mathis A, Sahel J, Massin P, Dosquet C, et al. Effect of autologous platelet concentrate in surgery for idiopathic macular hole: results of a multicenter, double-masked, randomized trial. Platelets in Macular Hole Surgery Group. Ophthalmology. 1999;106:932鈥?. CrossRef
  32. Taggart DP, Lees B, Gray A, Altman DG, Flather M, Channon K, et al. Protocol for the Arterial Revascularisation Trial (ART). A randomised trial to compare survival following bilateral versus single internal mammary grafting in coronary revascularisation. Trials. 2006;7:7. CrossRef
  33. Taggart DP, D鈥橝mico R, Altman DG. Effect of arterial revascularisation on survival: a systematic review of studies comparing bilateral and single internal mammary arteries. Lancet. 2001;358:870鈥?. CrossRef
  
• 刊物主题：Medicine/Public Health, general; Biomedicine general; Statistics for Life Sciences, Medicine, Health Sciences;
• 出版者：BioMed Central
• ISSN：1745-6215

文摘

Background Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of a particular magnitude exists. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of participants should be recruited. Despite the critical role of the target difference for the primary outcome in the design of randomised controlled trials, its determination has received surprisingly little attention. This article provides guidance on the specification of the target difference for the primary outcome in a sample size calculation for a two parallel group randomised controlled trial with a superiority question. Methods This work was part of the DELTA (Difference ELicitation in TriAls) project. Draft guidance was developed by the project steering and advisory groups utilising the results of the systematic review and surveys. Findings were circulated and presented to members of the combined group at a face-to-face meeting, along with a proposed outline of the guidance document structure, containing recommendations and reporting items for a trial protocol and report. The guidance and was subsequently drafted and circulated for further comment before finalisation. Results Guidance on specification of a target difference in the primary outcome for a two group parallel randomised controlled trial was produced. Additionally, a list of reporting items for protocols and trial reports was generated. Conclusions Specification of the target difference for the primary outcome is a key component of a randomized controlled trial sample size calculation. There is a need for better justification of the target difference and reporting of its specification.