How the type of risk reduction influences required sample sizes in randomised clinical trials. Issue 11 (1st July 2004)

• Record Type: Journal Article
• Authors: Bruynesteyn, K; Wanders, A; Landewé, R; van der Heijde, D
• Is Part Of: Annals of the rheumatic diseases. Volume 63:Issue 11(2004)
• Page Start: 1368
• Page End: 1371
• Publication Date: 2004-07-01
• Subjects: ARR, absolute risk reduction -- CsA, ciclosporin A, DMARDs, disease modifying antirheumatic drugs -- MTX, methotrexate -- RA, rheumatoid arthritis -- RCT, randomised controlled trial -- RRR, relative risk reduction -- SSZ, sulfasalazine; rheumatoid arthritis -- radiography -- joint damage -- sample size -- risk reduction -- randomised clinical trials; Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/ard.2003.014035
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : To increase change between groups, randomised clinical trials (RCT) often include patients with high risk for a particular outcome, by inclusion criteria that select predictors for that outcome. This increases the statistical power, and fewer patients are required for that RCT. The way in which patient selection influences the power, and thus sample size required, depends on how an intervention reduces the individual risk: by an absolute or relative risk reduction model.