title: Rheumatoid arthritis antirheumatic drug trials. II. Tables for calculating sample size for clinical trials of antirheumatic drugs.
abstract: The calculation of sample size requires knowledge of the standard deviation (SD) of index variables. Unfortunately, there are no published lists of SD and it is exceedingly difficult to locate variance estimates based on relevant populations. We used standardized procedures to determine in 60 patients with rheumatoid arthritis (RA) the SD of key outcome measures recommended in current Food and Drug Administration and European League Against Rheumatism guidelines for RA clinical trials. We anticipate that these tables will be useful to clinical researchers in selecting outcome measures as well as for calculating sample size requirements for future clinical studies in RA.
authors.affiliation: Division of Rheumatology, University of Western Ontario, London, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Bellamy
authors.forename: T P
authors.initials: TP
authors.lastname: Anastassiades
authors.forename: W W
authors.initials: WW
authors.lastname: Buchanan
authors.forename: P
authors.initials: P
authors.lastname: Davis
authors.forename: P
authors.initials: P
authors.lastname: Lee
authors.forename: G A
authors.initials: GA
authors.lastname: McCain
authors.forename: G A
authors.initials: GA
authors.lastname: Wells
authors.forename: J
authors.initials: J
authors.lastname: Campbell
mesh_terms: D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000503:physiopathology; D002986:Clinical Trials as Topic; D006801:Humans; D017063:Outcome Assessment, Health Care; D010361:Patients; D012107:Research Design
chemical_list: D000893:Anti-Inflammatory Agents