Static magnetic fields for treatment of fibromyalgia: a randomized controlled trial

Abstract

Objective: To test effectiveness of static magnetic fields of two different configurations, produced by magnetic sleep pads, as adjunctive therapies in decreasing patient pain perception and improving functional status in individuals with fibromyalgia.

Design: Randomized, placebo-controlled, 6-month trial conducted from November 1997 through December 1998.

Setting and subjects: Adults who met the 1990 American College of Rheumatology criteria for fibromyalgia were recruited through clinical referral and media announcements and evaluated at a university-based clinic.

Interventions: Subjects in Functional Pad A group used a pad for 6 months that provided whole-body exposure to a low, uniform static magnetic field of negative polarity. Subjects in the Functional Pad B group used a pad for 6 months that exposed them to a low static magnetic field that varied spatially and in polarity. Subjects in two Sham groups used pads that were identical in appearance and texture to the functional pads but contained inactive magnets; these groups were combined for analysis. Subjects in the Usual Care group continued with their established treatment regimens.

Outcome measures: Primary outcomes were the change scores at 6 months in the following measures: functional status (Fibromyalgia Impact Questionnaire), pain intensity ratings, tender point count, and a tender point pain intensity score.

Results: There was a significant difference among groups in pain intensity ratings (p = 0.03), with Functional Pad A group showing the greatest reduction from baseline at 6 months. All four groups showed a decline in number of tender points, but differences among the groups were not significant (p = 0.72). The functional pad groups showed the largest decline in total tender point pain intensity, but overall differences were not significant (p = 0.25). Improvement in functional status was greatest in the functional pad groups, but differences among groups were not significant (p = 0.23).

Conclusions: Although the functional pad groups showed improvements in functional status, pain intensity level, tender point count, and tender point intensity after 6 months of treatment, with the exception of pain intensity level these improvements did not differ significantly from changes in the Sham group or in the Usual Care group.