RESEARCH - The placebo effect an its determinants in OA - meta-analysis of randomised controlled trials

[Guest guest]

Ann Rheum Dis. Published Online First: 9 June 2008. doi:10.1136/ard.2008.092015

Copyright © 2008 BMJ Publishing Group Ltd & European League Against

Rheumatism

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Extended Report

The placebo effect and its determinants in osteoarthritis –

meta-analysis of randomised controlled trials

W Zhang 1*, J on 1, A C 2, P A Dieppe 3 and M Doherty 1

1 Nottingham University, United Kingdom

2 Nottingham University Hospitals, United Kingdom

3 Oxford University, United Kingdom

Abstract

Objective: To examine the placebo effect and its potential

determinants in the treatment of osteoarthritis (OA).

Data sources: Systematic literature search of Medline, EMBASE,

Scientific Citation Index, CINAHL and Cochrane Library.

Review methods: Randomised placebo controlled trials in OA were

included. The placebo effect was defined as the overall change from

baseline in the placebo group. It was estimated as the effect size

(ES) - the standard mean difference between baseline and endpoint –

and this was compared with the ES obtained from untreated control. ES

for pain was the primary outcome. Statistical pooling was undertaken

as appropriate and 95% confidence interval (CI) was used for

comparison. Quality of trials was assessed and potential determinants

of placebo effect were examined using multiple regression analysis.

Partial regression coefficient () was used to present the adjusted

size of the association.

Results: We identified 198 trials with 193 placebo groups (16,364

patients) and 14 untreated control groups (1,167 patients) that met

our inclusion criteria. These included a range of therapies

(non-pharmacological, pharmacological and surgical treatments).

Placebo was effective at relieving pain (ES=0.51, 95%CI 0.46, 0.55 for

the placebo group and 0.03, 95%CI -0.13, 0.18 for untreated control).

Placebo was also effective at improving function and stiffness. The

pain-relieving effect increased when the active treatment effect

(=0.38, p<0.001), baseline pain (0.006, p=0.014) and sample size

(0.001, p=0.004) increased, and when placebo was given through

injections/needles (0.144, p=0.020).

Conclusion: Placebo is effective in the treatment of OA, especially

for pain, stiffness and self-reported function. The size of this

effect is influenced by the strength of the active treatment, the

baseline disease severity, the route of delivery and the sample size

of the study.

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http://ard.bmj.com/cgi/content/abstract/ard.2008.092015v1?papetoc

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Not an MD

[Guest guest]

> Conclusion: Placebo is effective in the treatment of OA, especially

> for pain, stiffness and self-reported function. The size of this

> effect is influenced by the strength of the active treatment, the

> baseline disease severity, the route of delivery and the sample size

> of the study.

Wow - for those who truly suffer from OsteoArthritis (a type of

arthritis that is caused by the breakdown and eventual loss of the

cartilage of one or more joints), this study suggests their pain and

stiffness isn't real. Its a sad day in the medical field when a

study suggests someone could be faking their symptoms.

The definition of Placebo according to MedicineNet.com:

Placebo: A " sugar pill " or any dummy medication or treatment. For

example, in a controlled clinical trial, one group may be given a

real medication while another group is given a placebo that looks

just like it in order to learn if the differences observed are due to

the medication or to the power of suggestion. Placebos are widely

used in drug trials.

[Guest guest]

I understand that, but a placebo isn't a " real " treatment - there are

no medicinal properties as they consist of either " inert " ingredients

or are a " sugar pill " . I guess I'm not understanding how they figure

a placebo could be beneficial in treating OA with what my

understanding of what a placebo is.

Doreen

> >> Conclusion: Placebo is effective in the treatment of OA,

especially

> >> for pain, stiffness and self-reported function. The size of this

> >> effect is influenced by the strength of the active treatment, the

> >> baseline disease severity, the route of delivery and the sample

size

> >> of the study.

> >

> > Wow - for those who truly suffer from OsteoArthritis (a type of

> > arthritis that is caused by the breakdown and eventual loss of the

> > cartilage of one or more joints), this study suggests their pain

and

> > stiffness isn't real. Its a sad day in the medical field when a

> > study suggests someone could be faking their symptoms.

> >

> > The definition of Placebo according to MedicineNet.com:

> >

> > Placebo: A " sugar pill " or any dummy medication or treatment. For

> > example, in a controlled clinical trial, one group may be given a

> > real medication while another group is given a placebo that looks

> > just like it in order to learn if the differences observed are

due to

> > the medication or to the power of suggestion. Placebos are widely

> > used in drug trials.

>

[Guest guest]

Thank you (and ) for the additional information. I now

understand that the purpose of a placebo (in treatment) is to get the

body to release its own opiods/endorphins in managing pain. I'm very

familiar with the Lamaze method used during childbirth and have used

it in other situations as well. My hubby went through bio-feedback

and the expectations were the same. I understand that for some

people, those two methods are not enough to encourage the body to

release its own natural pain reliever and by administering the

placebo, it affects the brain in a similar manner.

I honestly thought at first that the study was ridiculous and unfair

to the person suffering from pain. Now that I have read those

additional articles, I can see how it WILL work. I also think it is

an excellent alternative to the addictive and dangerous properties

associated with pain medications.

> Did you read this article I posted yesterday?

>

> /message/114104

>

>

> Here are a couple of others:

>

> http://www.newscientist.com/article.ns?id=dn7892

>

> http://www.physorg.com/news105029324.html

>

>

http://www.cancer.org/docroot/ETO/content/ETO_5_3x_Placebo_Effect.asp

>

>

>

> Not an MD

>

>

>

> On Sat, Jun 14, 2008 at 6:42 PM, Mimi <mimi212@...> wrote:

> > I understand that, but a placebo isn't a " real " treatment - there

are

> > no medicinal properties as they consist of either " inert "

ingredients

> > or are a " sugar pill " . I guess I'm not understanding how they

figure

> > a placebo could be beneficial in treating OA with what my

> > understanding of what a placebo is.

> >

> > Doreen

> >

> >

> >> >> Conclusion: Placebo is effective in the treatment of OA,

> > especially

> >> >> for pain, stiffness and self-reported function. The size of

this

> >> >> effect is influenced by the strength of the active treatment,

the

> >> >> baseline disease severity, the route of delivery and the

sample

> > size

> >> >> of the study.

> >> >

> >> > Wow - for those who truly suffer from OsteoArthritis (a type of

> >> > arthritis that is caused by the breakdown and eventual loss of

the

> >> > cartilage of one or more joints), this study suggests their

pain

> > and

> >> > stiffness isn't real. Its a sad day in the medical field when a

> >> > study suggests someone could be faking their symptoms.

> >> >

> >> > The definition of Placebo according to MedicineNet.com:

> >> >

> >> > Placebo: A " sugar pill " or any dummy medication or treatment.

For

> >> > example, in a controlled clinical trial, one group may be

given a

> >> > real medication while another group is given a placebo that

looks

> >> > just like it in order to learn if the differences observed are

> > due to

> >> > the medication or to the power of suggestion. Placebos are

widely

> >> > used in drug trials.

> >>

>

[Guest guest]

Yes, and let's face it - a placebo effect is still an effect. I'd much

rather get the effect without the meds, if it's possible! That the mind

is able to heal or lessen symptoms does NOT mean that the mind caused

the issues originally - that is a common misunderstanding. The

causality doesn't need to work both ways.

>

> The mind-body connection is really amazing. I worked in nursing for

many years and have seen placebos work and also not work for different

types of pain. I think sometimes it was just the anticipation of pain

relief and maybe the relaxation that came from thinking it would work

allowed the body to help itself. I have also used Lamaze (a childbirth

technique using focus and relaxation) with post op surgery patients who

could not use traditional medications to help with pain control with

success. I have used modified versions with my kids for minor injuries

with success. I know with myself personally that relaxation and focus

can play a big part in how I deal with pain.