RANDOMIZED, PLACEBO-CONTROLLED TRIAL OF WITHDRAWAL OF SLOW-ACTING ANTIRHEUMATIC DRUGS AND OF OBSERVER BIAS IN RHEUMATOID-ARTHRITIS

Patients with rheumatoid arthritis, in stable treatment with methotrex ate, penicillamine, or sulfasalazine, were randomized in a double-blin d fashion either to continuation of their usual treatment or to placeb o. 112 patients were included; 52 patients who refused participation h ad 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 occu rred 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 patie nts guessed their treatment correctly more often than expected (p=0.02 ) because of the perceived effect. None of the two observers guessed b etter than chance: and there were no differences between the observers ' evaluations of the joints. The effect of slow-acting antirheumatic d rugs was unequivocal and no observer bias occurred.