Cath Lab Digest

S cant information is available in the English language scientific literature to support the extraordinary growth of the use of complementary therapies for treatment of health problems. This article discusses the difficulties encountered in attempting to investigate one of the available complementary treatments - magnetic therapy - and its effect on wound healing. The magnets used for this study do not produce thermal or ionizing effects in tissue; therefore, they are not considered medical devices. The magnetic field generated by the magnets is fixed in terms of intensity at any measured point, in contrast to the changing fields associated with electrical power sources. Because these magnets are not regulated by the FDA or other such agency, they may be purchased without a physician's prescription and used without the supervision of a healthcare professional.

Literature Review

In 1993, one-third of Americans spent $13.7 billion on complementary medical treatments.¹ By 1997, these numbers had grown - one-half of all Americans used some form of complementary healthcare at a cost of $36 billion out-of-pocket per year.² As a result, in 1999, the federal government established the National Center for Complementary and Alternative Medicine with a $50 million budget within the National Institutes for Health (NIH). The Center's mission is to seek data on the efficacy of alternative/complementary healthcare and to establish an information clearinghouse.²

A 1992 report to the NIH on bioelectromagnetics identified wound healing as one of the new or unconventional uses for nonthermal, nonionizing electromagnetic (EM) fields.³ Using a static magnetic field (SMF) for therapeutic purposes is generally referred to as static magnetic field therapy and involves exposing the body or specific body part to a fixed magnetic field through the use of magnetized device.⁴ Although the effectiveness of pulsed electromagnetic stimulation in wound healing is fairly well documented,^5-8 only one case report⁹ and one study¹⁰ using SMF therapy were found; both had positive findings. The chronic wound population involved with SMF therapy in this study was comprised of individuals with diabetic foot ulcers. The hypothesis of the study was that people with diabetes who receive SMF therapy in addition to standard treatment (sharp debridement, twice-daily dressing changes, antibiotics when needed, offloading the ulcer) would have accelerated healing of their foot ulcers compared to people with diabetes who receive the standard treatment and placebo.

Methods

The authors anticipated recruiting 70 subjects from patients receiving treatment at a wound care center (WCC). In addition to having a diabetic foot ulcer, subjects had to be 18 years of age or older, able to read and understand English, and living in an environment where they had control over application and removal of the insole of the shoe (ie, home setting, subject or family member to assume responsibility for insole).

The sample size estimate was based upon one-way analysis of variance (ANOVA) and the additional effect magnets were expected to have over the standardized healing rate protocol established by the WCC. The authors estimated that by enrolling 70 subjects (35 per group), would provide 80% power with a p = 0.05.