Randomised controlled trial of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee

doi:10.1136/bmj.329.7480.1450

BMJ 2004;329:1450-1454 (18 December), doi:10.1136/bmj.329.7480.1450

The limits of medicine

Randomised controlled trial of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee

Tim Harlow, general practitioner¹, Colin Greaves, research fellow², Adrian White, senior research fellow³, Liz Brown, research assistant⁴, Anna Hart, statistician⁵, Edzard Ernst, professor of complementary medicine⁴

¹ College Surgery, Cullompton, Devon EX15 1TG, ² Peninsula Medical School (Primary Care), Exeter EX2 5DW, ³ Peninsula Medical School, Tamar Science Park, Plymouth PL6 8BX, ⁴ Peninsula Medical School (Complementary Medicine), Exeter EX2 4NT, ⁵ Lancashire School of Health and Postgraduate Medicine, University of Central Lancashire, Preston PR1 2HE

Correspondence to: T Harlow, Hospiscare, Dryden Road, Exeter EX2 5JJ timharlow{at}eclipse.co.uk

Abstract

Objective To determine the effectiveness of commercially availablemagnetic bracelets for pain control in osteoarthritis of thehip and knee.

Design Randomised, placebo controlled trial with three parallelgroups.

Setting Five rural general practices.

Participants 194 men and women aged 45-80 years with osteoarthritisof the hip or knee.

Intervention Wearing a standard strength static bipolar magneticbracelet, a weak magnetic bracelet, or a non-magnetic (dummy)bracelet for 12 weeks.

Main outcome measures Change in the Western Ontario and McMasterUniversities osteoarthritis lower limb pain scale (WOMAC A)after 12 weeks, with the primary comparison between the standardand dummy groups. Secondary outcomes included changes in WOMACB and C scales and a visual analogue scale for pain.

Results Mean pain scores were reduced more in the standard magnetgroup than in the dummy group (mean difference 1.3 points, 95%confidence interval 0.05 to 2.55). Self reported blinding statusdid not affect the results. The scores for secondary outcomemeasures were consistent with the WOMAC A scores.

Conclusion Pain from osteoarthritis of the hip and knee decreaseswhen wearing magnetic bracelets. It is uncertain whether thisresponse is due to specific or non-specific (placebo) effects.

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Rapid Responses:

Read all Rapid Responses

Was the study really good enough?: Edoardo Cervoni
bmj.com, 17 Dec 2004 [Full text]
Why not test the ultimate magnet?: Christopher I Pelton
bmj.com, 17 Dec 2004 [Full text]
Randomised controlled trial of magnetic bracelets for relieving pain in osteoarthritis of the hip and knee: Helene C Faure
bmj.com, 17 Dec 2004 [Full text]
WHY NOT TRY MAGNETS ON ANIMALS: Victor. C. Green
bmj.com, 17 Dec 2004 [Full text]
Re: Was the study really good enough?: Curtis Bennett
bmj.com, 17 Dec 2004 [Full text]
Better studies on magnets for relieving pain in osteoarthritis of the knee must include objective laboratory tests of synovial inflammatory markers: David Gurwitz
bmj.com, 17 Dec 2004 [Full text]
Which bracelet?: Bernard Badley
bmj.com, 18 Dec 2004 [Full text]
Re: Was the study really good enough? Clearly not!: David Jameson
bmj.com, 19 Dec 2004 [Full text]
Conclusions of this study are overoptimistic: Miquel A Belmonte
bmj.com, 19 Dec 2004 [Full text]
Re: Better studies on magnets for relieving pain in osteoarthritis of the knee must include objective laboratory tests of synovial inflammatory markers: Christine Harrison
bmj.com, 20 Dec 2004 [Full text]
Re: Which bracelet?: Victor C. Green
bmj.com, 21 Dec 2004 [Full text]
Blinding optimism attracts magnet researchers to wrong conclusion: Peter H Canter
bmj.com, 20 Dec 2004 [Full text]
Re: Which bracelet?: Christine Harrison
bmj.com, 20 Dec 2004 [Full text]
Re: WHY NOT TRY MAGNETS ON ANIMALS: C Gill
bmj.com, 21 Dec 2004 [Full text]
Re: Why not test the ultimate magnet?: C. R. Gill
bmj.com, 21 Dec 2004 [Full text]
Re: WHY NOT TRY MAGNETS ON ANIMALS: Sarah M D Fishwick
bmj.com, 21 Dec 2004 [Full text]
Re: Which bracelet?: Ray Padfield -Krala
bmj.com, 21 Dec 2004 [Full text]
(Carpal) Tunnel Vision!: Valerie M Daykin
bmj.com, 22 Dec 2004 [Full text]
Tiny bracelets: Hugh de Glanville
bmj.com, 22 Dec 2004 [Full text]
Magnets and severity of OA--Is there a corelation?: ABHIJIT M. BHOSALE
bmj.com, 22 Dec 2004 [Full text]
The study draws the right conclusions- authors reply: Tim N Harlow, et al.
bmj.com, 22 Dec 2004 [Full text]
Forget scepticism - give it a try!!: Kathleen B. Robinson
bmj.com, 22 Dec 2004 [Full text]
Re: Re: Which bracelet?: Kay A Gill
bmj.com, 22 Dec 2004 [Full text]
Misleading article: N A Shah, et al.
bmj.com, 27 Dec 2004 [Full text]
Magnets: Significant results, or placebo power?: Ano L. Lobb
bmj.com, 29 Dec 2004 [Full text]
Re: Re: Was the study really good enough? Clearly not!: Daniel E Moerman
bmj.com, 29 Dec 2004 [Full text]
Re: Misleading article: Tim N Harlow
bmj.com, 29 Dec 2004 [Full text]
Which bracelet? The one with CRP (Central-Reverse-Polarity) a money refund guarantee and a first class after sales service.: David W Haslam
bmj.com, 30 Dec 2004 [Full text]
Re: Magnets: Significant results, or placebo power?: Tony Floyd
bmj.com, 30 Dec 2004 [Full text]
Re: Misleading article: Curtis Bennett
bmj.com, 30 Dec 2004 [Full text]
Unethical to ignore: Jim York
bmj.com, 30 Dec 2004 [Full text]
Re: Re: Which bracelet?: Ray Padfield-Krala
bmj.com, 31 Dec 2004 [Full text]
Re: WHY NOT TRY MAGNETS ON ANIMALS: William N. Elwood
bmj.com, 2 Jan 2005 [Full text]
More Open Minded Attitude Required: Bill Lawson
bmj.com, 3 Jan 2005 [Full text]
Many forms of bias: Everett L Williams
bmj.com, 4 Jan 2005 [Full text]
Re: Re: Was the study really good enough? Clearly not!: c gill
bmj.com, 6 Jan 2005 [Full text]
Re: Many forms of bias: Chris Gill
bmj.com, 8 Jan 2005 [Full text]
Re: Misleading article: Christine Harrison
bmj.com, 8 Jan 2005 [Full text]
Absence of radiological report: Christopher J F Potter
bmj.com, 10 Jan 2005 [Full text]
Placebo? It could be a two-edged sword.: Chris B Thayer
bmj.com, 11 Jan 2005 [Full text]
Re: Misleading article: Richard L Peacocke
bmj.com, 12 Jan 2005 [Full text]
Very interesting study: Matthew L Grove
bmj.com, 12 Jan 2005 [Full text]
Clinical Trial????: Loretta Mutton
bmj.com, 19 Jan 2005 [Full text]
Magna Mallarca: Dr. Herbert H. Nehrlich
bmj.com, 20 Jan 2005 [Full text]
Re: Magna Mallarca: chris gill
bmj.com, 21 Jan 2005 [Full text]
Re: Re: Magna Mallarca: Dr. Herbert H. Nehrlich
bmj.com, 23 Jan 2005 [Full text]
A typical cross section of views!: Chris Sergeant
bmj.com, 28 Jan 2005 [Full text]
The effects of magnetic bracelets for relieving osteoarthritic pain and its relevance: Sita M Bierma-Zeinstra
bmj.com, 3 Feb 2005 [Full text]
Not a placebo!: Kevin Mathis
bmj.com, 12 Jun 2005 [Full text]
Mechanisms of Magnetic Bracelets: Kenneth J. Dillon
bmj.com, 4 Jul 2005 [Full text]
Re: Which bracelet?: Eric D Knapp
bmj.com, 22 Oct 2007 [Full text]
Stimulating conversation is priceless: Kim I. DiJulio
bmj.com, 12 Jan 2009 [Full text]
Other responses of interest: Michael Dowling
bmj.com, 27 Aug 2009 [Full text]