Another useful waste of time? Hitching a ride on the back of placebo.
This excellent study and spark to debate (1) showed that both
interventions were better than waiting for care – and clearly both
interventions were useful (responders were ‘46% in the acupuncture group,
35% in the minimal acupuncture group, and 4% in the waiting list group. ‘
May be this is another ‘double positive paradox’ where the attempt at
a ‘sham’ therapy turns out to be so active in its own right, that it
raises the bar for any other competing treatment (2). Sometimes those
‘non-specific effect’ of intention, touch, care, expectation, and other
context impacts, will take someone’s healing so far that any other
effective treatment will have difficulty achieving an additional effect -
all the more perhaps when with acupuncture people are claiming effects
from non-specific needling. The active intervention is a rider hitching a
lift on the back of the already galloping horse of placebo.
So we may be seeing the successful addition of a supplementary effect
from ‘real’ acupuncture struggling to show through. However this is all
the more complex because you cannot double-blind acupuncture. The
additional effect may in turn be wholly, (or even more complexly, partly)
due to the ‘transmitted clinicians expectation of outcome’ becoming more
enlivened when they are administering what they consider a better-than-the
-sham intervention. Work at the University of Glasgow showed patients with
asthma reacting in very different (even opposite) ways to 2 identical
placebos given by the same care team - when the context changed from
single blinding to double blinding, in turn altering the researchers and
clinicians expectations (3). This echoed Gracely et als finding of
different analgesic effects with altered clinician expectations (4).
How about a fresh post-hoc power calculation from the team: In a
future study, how many patients would be needed to distinguish the effects
of the two ‘active’ interventions here?
David Reilly, Director, ADHOM Academic Departments, The Centre for
Integrative Care, Glasgow Homoeopathic Hospital, 1053 Great Western Road,
Glasgow G12 OXQ davidreilly1@compuserve.com
1. Melchart D, Streng A, Hoppe A, et al. Acupuncture in patients with
tension-type headache: randomised controlled trial. BMJ 2005;331:376-382
(13 August), doi:10.1136/bmj.38512.405440.8F (published 29 July 2005
2. Reilly D. When is useful improvement a waste of time? Double
positive paradox of negative trials. BMJ 2002;325:41 ( 6 July )
3. Reilly DT, Taylor MA. Individual Patients and Their Responses.
Published in - Developing Integrated Medicine. RCCM Research Fellowship
in Complementary Medicine. .Complementary Therapies in Medicine 1993;1
Suppl 1: 26-28.
Rapid Response:
Another useful waste of time? Hitching a ride on the back of placebo.
This excellent study and spark to debate (1) showed that both
interventions were better than waiting for care – and clearly both
interventions were useful (responders were ‘46% in the acupuncture group,
35% in the minimal acupuncture group, and 4% in the waiting list group. ‘
May be this is another ‘double positive paradox’ where the attempt at
a ‘sham’ therapy turns out to be so active in its own right, that it
raises the bar for any other competing treatment (2). Sometimes those
‘non-specific effect’ of intention, touch, care, expectation, and other
context impacts, will take someone’s healing so far that any other
effective treatment will have difficulty achieving an additional effect -
all the more perhaps when with acupuncture people are claiming effects
from non-specific needling. The active intervention is a rider hitching a
lift on the back of the already galloping horse of placebo.
So we may be seeing the successful addition of a supplementary effect
from ‘real’ acupuncture struggling to show through. However this is all
the more complex because you cannot double-blind acupuncture. The
additional effect may in turn be wholly, (or even more complexly, partly)
due to the ‘transmitted clinicians expectation of outcome’ becoming more
enlivened when they are administering what they consider a better-than-the
-sham intervention. Work at the University of Glasgow showed patients with
asthma reacting in very different (even opposite) ways to 2 identical
placebos given by the same care team - when the context changed from
single blinding to double blinding, in turn altering the researchers and
clinicians expectations (3). This echoed Gracely et als finding of
different analgesic effects with altered clinician expectations (4).
How about a fresh post-hoc power calculation from the team: In a
future study, how many patients would be needed to distinguish the effects
of the two ‘active’ interventions here?
David Reilly, Director, ADHOM Academic Departments, The Centre for
Integrative Care, Glasgow Homoeopathic Hospital, 1053 Great Western Road,
Glasgow G12 OXQ
davidreilly1@compuserve.com
1. Melchart D, Streng A, Hoppe A, et al. Acupuncture in patients with
tension-type headache: randomised controlled trial. BMJ 2005;331:376-382
(13 August), doi:10.1136/bmj.38512.405440.8F (published 29 July 2005
2. Reilly D. When is useful improvement a waste of time? Double
positive paradox of negative trials. BMJ 2002;325:41 ( 6 July )
3. Reilly DT, Taylor MA. Individual Patients and Their Responses.
Published in - Developing Integrated Medicine. RCCM Research Fellowship
in Complementary Medicine. .Complementary Therapies in Medicine 1993;1
Suppl 1: 26-28.
4. Gracely RH, Dubner R, Deeter WR, Wolksee PJ. Clinicians'
expectations influence placebo analgesia. Lancet 1985;i:43
Competing interests:
None declared
Competing interests: No competing interests