title: Randomized, placebo controlled trial of withdrawal of slow-acting antirheumatic drugs and of observer bias in rheumatoid arthritis.
abstract: Patients with rheumatoid arthritis, in stable treatment with methotrexate, penicillamine, or sulfasalazine, were randomized in a double-blind fashion either to continuation of their usual treatment or to placebo. 112 patients were included; 52 patients who refused participation had no more severe disease than the others. The patients felt worse on placebo than on active drug (p = 0.002). The mean differences in number of tender, painful and swollen joints after one month were 2.4 (p = 0.08), 3.0 (p = 0.12) and 2.2 (p = 0.03), respectively. Treatment failure occurred for 42 patients of whom 33 received placebo (p = 0.000,001). There was no difference in the severity of side effects (p = 0.91). The patients guessed their treatment correctly more often than expected (p = 0.02) because of the perceived effect. None of the two observers guessed better than chance, and there were no differences between the observers' evaluations of the joints. The effect of slow-acting antirheumatic drugs was unequivocal and no observer bias occurred.
authors.affiliation: Department of Rheumatology, Hvidovre Hospital, Copenhagen, Denmark.
authors.forename: P C
authors.initials: PC
authors.lastname: Gøtzsche
authors.forename: M
authors.initials: M
authors.lastname: Hansen
authors.forename: M
authors.initials: M
authors.lastname: Stoltenberg
authors.forename: A
authors.initials: A
authors.lastname: Svendsen
authors.forename: J
authors.initials: J
authors.lastname: Beier
authors.forename: K L
authors.initials: KL
authors.lastname: Faarvang
authors.forename: M
authors.initials: M
authors.lastname: Wangel
authors.forename: L
authors.initials: L
authors.lastname: Rydgren
authors.forename: P
authors.initials: P
authors.lastname: Halberg
authors.forename: P
authors.initials: P
authors.lastname: Juncker
authors.forename: V
authors.initials: V
authors.lastname: Andersen
authors.forename: T M
authors.initials: TM
authors.lastname: Hansen
authors.forename: L
authors.initials: L
authors.lastname: Endahl
mesh_terms: D000368:Aged; D018501:Antirheumatic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000453:epidemiology* / Q000523:psychology; D006801:Humans; D008875:Middle Aged; D015588:Observer Variation; D012647:Self-Assessment; D012720:Severity of Illness Index; D013375:Substance Withdrawal Syndrome / Q000453:epidemiology* / Q000523:psychology; D013997:Time Factors
chemical_list: D018501:Antirheumatic Agents