Wolsko PM , Eisenberg DM , Simon LS , Davis RB , Walleczek J ,
Mayo-Smith M , Kaptchuk TJ , Phillips RS .
Division for Research and Education, Harvard Medical School, Boston, MA, USA.
CONTEXT: Outpatient clinical studies of magnet therapy, a complementary therapy commonly used to treat osteoarthritis (OA), have been limited by the absence of a credible placebo control.
OBJECTIVE: Our objective was to assess the feasibility and promise of studying static magnetic therapy for knee OA and determine the ability of a new placebo-magnet device to provide concealment of group assignment.
DESIGN: Randomized, double-blind, placebo-controlled clinical trial.
SETTING: Academic teaching hospital in Boston.
PARTICIPANTS: We enrolled 29 subjects with idiopathic or post-traumatic OA of the knee.
INTERVENTIONS: Subjects received either high-strength magnetic (active) or placebo-magnetic (placebo) knee sleeve treatment for 4 hours in a monitored setting and self-treatment 6 hours daily for 6 weeks.
MAIN OUTCOME MEASURES: Primary outcomes were change in knee pain as measured by the WOMAC Osteoarthritis Index Pain Subscale at 6 weeks and extent of group concealment at study end.
RESULTS: At 4 hours, VAS pain scores (+/- SE) on a 5-item scale (0-500, 500 worst) decreased 79 +/- 18 mm in the active group and 10 +/- 21 mm in the placebo group (P < 0.05). There were no significant differences in any primary or secondary measure of efficacy between the treatment groups at 6 weeks. Despite widespread testing for magnetic properties, at study end, 69% of the active group and 77% of the placebo group (P > 0.2) believed that they had been assigned to the active treatment group.
CONCLUSION: Despite our small sample size, magnets showed statistically significant efficacy compared to placebo after 4 hours under rigorously controlled conditions. The sustained efficacy of magnetic therapy for knee osteoarthritis could be assessed in an adequately powered trial utilizing an appropriate control such our new placebo-magnet device.
Altern Ther Health Med. 2004 Mar-Apr;10(2):36-43.