Two configurations of static magnetic fields for treating rheumatoid arthritis of the knee: A double-blind clinical trial

Objective: To assess the efficacy of a nonpharmacologic, noninvasive static magnetic device as adjunctive therapy for knee pain in patients with rheum atoid arthritis (RA). Design: Randomized, double-blind, controlled, multisite clinical trial. Setting: An American and a Japanese academic medical center as well as 4 co mmunity rheumatology and orthopedics practices. Patients: Cohort of 64 patients over age 18 years with rheumatoid arthritis and persistent knee pain, rated greater than 40/100mm, despite appropriate use of medications. Intervention: Four blinded MagnaBloc(TM) (with 4 steep field gradients) or control devices (with 1 steep field gradient) were taped to a knee of each subject for 1 week. Main Outcome Measures: The American College of Rheumatology recommended cor e set of disease activity measures for RA clinical trials and subjects' ass essment of treatment outcome. Results: Subjects randomly assigned to the MagnaBloc (n = 38) and control t reatment groups (n = 26) reported baseline pain levels of 63/100mm. and 61/ 100mm, respectively. A greater reduction in reported pain in the MagnaBloc group was sustained through the 1-week follow-up (40.4% vs 25.9%) and corro borated by twice daily pain diary results (p < .0001 for each vs baseline). However, comparison between the 2 groups demonstrated a statistically insi gnificant difference (p < .23). Subjects in the MagnaBloc group reported an average decrease in their global assessment of disease activity of 33% ove r 1 week, as compared with a 2% decline in the control group (p < .01). Aft er 1 week, 68% of the MagnaBloc treatment group reported feeling better or much better, compared with 27% of the control group, and 29% and 65%, respe ctively, reported feeling the same as before treatment (P < .01). Conclusions: Both devices demonstrated statistically significant pain reduc tion in comparison to baseline, with concordance across multiple indices. H owever, a significant difference was not observed between the 2 treatment g roups (p < .23). In future studies, the MagnaBloc treatment should be compa red with a nonmagnetic placebo treatment to characterize further its therap eutic potential for treating RA. This study did elucidate methods for condu cting clinical trials with magnetic devices.