Complementary Therapies in Medicine (2008) 16, 139—146
available at www.sciencedirect.com
journal homepage: www.elsevierhealth.com/journals/ctim
Acupuncture for acute non-specific low back
pain: A pilot randomised non-penetrating
sham controlled trial
S. Kennedya, G.D. Baxterb, D.P. Kerra, I. Bradburya,
J. Parkc, S.M. McDonougha,∗
aHealth and Rehabilitation Sciences Research Institute, School of Health Sciences, University of Ulster,
Northern Ireland, United Kingdom
bCentre for Physiotherapy Research, School of Physiotherapy, University of Otago, New Zealand
cDivision for Research and Education in Complementary and Integrative Medical Therapies, Harvard Medical School,
Osher Institute, USA
Available online 27 April 2007
Low back pain;
Objective: A pilot study to assess the feasibility of a trial to investigate the efficacy of acupunc-
ture compared to placebo needling for the treatment of acute low back pain (LBP). As part of
this, the study was designed to establish the credibility of the placebo control, and to provide
data to inform a power analysis to determine numbers for a future trial.
Study design: A pilot patient and assessor blinded randomized controlled trial.
Setting: Primary care health centre facility, South and East Belfast Trust, Northern Ireland.
Patients: Patients from the physiotherapy waiting list (n=48) with LBP of less than 12 weeks
Outcome measures: Roland and Morris Disability Questionnaire (RMDQ), Visual Analogue Scale
(VAS), medication use and an exit questionnaire were completed at baseline, end of treatment,
and at 3 months follow up.
Results: Ninety-four percent (45/48) of patients completed assigned treatment, 83% (40/48)
completed 3 months follow-up. The sham needle used here proved to be credible: 91.7% in
the placebo group believed they had received acupuncture, compared to 95.8% in the verum
acupuncture group. Differences in baseline characteristics were accounted for using ANCOVA.
There was no significant difference between groups on the RMDQ over time. For pain, the only
statistically significant difference was at the 3 months follow up (worst VAS, point estimate,
18.7, 95% CI 1.5—36.0, p=0.034). The majority of patients were taking some form of analgesic
medication for LBP at the start of treatment (n=44; 92%), and at the end of treatment the
verum acupuncture group were taking significantly fewer tablets of pain control medication
(mean (S.D.): 1.0±0.3) than the placebo group (mean (S.D.): 4.2±0.6, p<0.05). Based upon
∗Corresponding author. Tel.: +44 2890366459; fax: +44 2890368068.
E-mail address: email@example.com (S.M. McDonough).
0965-2299/$ — see front matter © 2007 Elsevier Ltd. All rights reserved.
140S. Kennedy et al.
these data, power analysis (power=90%, alpha=0.05, minimal clinically important difference
(MCID) for RMDQ=2.5 points) indicated that 120 participants (60 per group) would be needed to
complete an adequately powered randomized controlled trial.
Conclusions: This study has demonstrated the feasibility of a randomized controlled trial of
penetrating needle acupuncture compared to a non-penetrating sham for the treatment of acute
LBP in primary care; 120 participants would be required in a fully powered trial. The placebo
needle used in this study proved to be a credible form of control.
© 2007 Elsevier Ltd. All rights reserved.
An unresolved question concerning acupuncture is whether
there is a specific effect attributable to the needling proce-
dure itself1; to address this issue requires trials using valid
sham (placebo) controls.1,2
Several non-penetrating needles have been developed
(i.e. The Streitberger needle and The Park Sham Device),
which have both been shown to be credible and valid con-
trols for acupuncture trials.3—7To date, no studies have
assessed their potential utility in trials for low back pain
Two recent systematic reviews have highlighted the lack
of research to support the use of acupuncture in acute LBP,
and the need for more well-controlled trials in such an
Therefore, the aim of this study was to test the feasibil-
ity of a randomized controlled trial to compare the efficacy
of verum acupuncture to a non-penetrating sham needling
control in acute LBP. Specific objectives were first to provide
necessary data upon which to base a power analysis and
secondly to assess the credibility of the proposed placebo
This was a pilot (feasibility) study10,11for a patient and
assessor blind randomised controlled trial. Subjects were
randomly allocated into groups using a computer generated
randomization table (http://www.randomization.com). To
ensure concealment of allocation, an administrative assis-
tant not otherwise involved in the study held the
Ethical approval was gained from the Queens Univer-
sity Belfast Research Ethics Committee, Northern Ireland.
Approval was also gained from South and East Belfast Trust
where the trial was completed.
Patients currently on the waiting list for physiotherapy
through referral by their general practitioner (GP) were con-
tacted by telephone and screened for inclusion in the study.
Adults able to give informed consent, males and females
aged 18—70 years. Current episode of non-specific LBP, with
or without referred pain, of up to 12 weeks duration. LBP
was defined as pain localised below the lowest ribs, and
above the inferior gluteal folds, with or without radiation
to the lower extremities.12
Pain lasting more than 12 weeks. Presentation of red flags
as defined by the Clinical Standards Advisory Guidelines13;
contra-indications to acupuncture or previous acupuncture
treatment; conflicting or ongoing treatment.
A full conventional clinical assessment was carried out
at first attendance by the treating therapist to ensure
the patient fulfilled the inclusion criteria. Patients were
requested to continue normal activities, and to avoid other
forms of treatment for the duration of the study, apart
from routine physician management and analgesics. Patients
were informed that they may or may not receive acupunc-
acupuncture. Therapists were not permitted to use any
treatments other than those in the designated protocol; all
treatment records were available in order to verify adher-
ence to the protocol.
Both verum and sham controlled treatments were per-
formed by the same senior experienced physiotherapists
(n=3); each had a minimum of 10 years clinical experience,
and were members of the Acupuncture Association of Char-
tered Physiotherapists (AACP).14Patients were allocated to
the therapists in sequence so that equal numbers of patients
were allocated to each therapist.
Acupuncture style was based on a
western medical approach: unilateral or bilateral points
were chosen to effect analgesia according to the patient’s
pattern of pain.15Each therapist chose points from a
set range commonly used in LBP (based on review of
textbooks,16—21RCTs22,23; confirmed by local expert opinion);
see Table 1.
Patients were treated in prone lying and received a min-
imum of three and a maximum of 12 treatments over a
4—6 weeks period. Frequency of treatment was once or
twice a week depending on symptom severity, and availabil-
ity of appointments, and was determined by the treating
therapist. Within each treatment the therapist inserted
8—13 needles which were stimulated manually every 5min
until subjective acupuncture specific sensation or de qi
Acupuncture for acute low back pain141
Location Method of insertion
Below spinous process 4th lumbar vertebra
Below spinous process 2nd lumbar vertebra
1.5 cun lateral to lower border of spinous process 2nd
1.5 cun lateral to lower border of spinous process 4th
lumbar vertebra, level with iliac crest
Midway between ASIS and greater trochanter
Junction of middle and lateral third of the distance
between great trochanter and sacral hiatus
Midline lat aspect thigh (tip of middle finger)
In the depression anterior and inferior to fibula head
Middle of transverse gluteal fold
6 cun below BL36
Middle of transverse crease popliteal fossa
Centre of belly of gastrocnemius
Depression between lateral malleolus and TA
BL25 Perpendicular 1—1.5in.
was achieved, or for 30s using an even technique. Nee-
dle retention time was 30min per treatment. The Park
Sham Device (AcuPrime, UK) with verum acupuncture nee-
dles were used (Spring and Scarborough, Wujiang jia chen
Acupuncture Devices Co. Ltd.; sterile single use needles
with guide tube, size 0.25mm×40mm) to maintain patient
(AcuPrime, UK) was also used in the control group, so
that patients were blinded to treatment5,7; however in
this group non-penetrating sham needles were used which
touched but did not penetrate the skin (sterile single use
needles with guide tube, size 0.3mm×40mm, AcuPrime,
Dong Bang Acupuncture Inc, Korea). The same acupuncture
points and clinical protocol was followed for the control
as for the verum acupuncture group to ensure the same
Clinical guidelines recommend advice to
remain active and medication as routine care for acute
LBP.13,24Advice was standardised at the first treatment by
giving all participants the Back Book, an evidence-based
booklet, developed for use by patients with LBP.25Medica-
tion intake was not controlled and may have been prescribed
by the referring physician or obtained over the counter by
ment and patients were asked to complete a daily diary
to record the type of medication, the dose in mg and the
number taken per day.
Given the nature of the treatments, it was pos-
sible to blind subjects but not therapists with respect to
the content of the interventions. The success of patient
blinding was assessed at the end of treatment. The primary
researcher, who was unaware of patient allocation until the
completion of the data analysis, carried out data collection
at all time points.
Compliance and drop-outs.
as receipt of less than three treatments, but such patients
were included in subsequent follow-ups for the purposes of
intention-to treat analysis.
same Park Sham Device
Non-compliance was defined
Outcome measures and follow-up procedures
A range of outcome measures were used as recom-
mended by Bombardier26: these included questionnaires
with proven psychometric properties for LBP-specific
functional disability26—28(Roland and Morris Disability Ques-
tionnaire, RMDQ) and pain29(Visual Analogue Scale, VAS),
and a multidimensional patient-centred questionnaire (work
absenteeism, analgesic medication consumption, additional
healthcare). These were completed at baseline, discharge,
and 3 months (by post). An exit questionnaire which assessed
patient satisfaction, success of blinding, and evaluated the
credibility of the placebo was also completed by each
patient at the end of treatment.
All variables were analysed using the Statistical Package
for the Social Sciences (SPSS) version 11. Intention-to-treat
analysis was carried out by an investigator who was masked
to treatment allocation. Any missing data were replaced
by carrying forward the most recent non-missing value.
Analysis of covariance (ANCOVA), using pretreatment value
as the covariate, was used to determine any differences
between the groups at the post-treatment and follow-up
visits. Exploratory analysis was carried out using numbers
of treatments as an additional covariate, and the numbers
of treatments between the groups was compared using the
Mann—Whitney test. Analgesic intake between the groups
was compared using the Van Elteren test, which is a modifi-
cation of the Mann—Whitney test that accounts for baseline
differences.30Because of doubts about the appropriateness
of parametric ANCOVA for medication usage, the baseline
medication usage was grouped into four categories using
quartile cut-points (category 1: 0—25%=0—2 tablets, cat-
egory 2: 25—50%=3—4 tablets, category 3: 50—75%=5—8
tablets and category 4: 75—100%=9—15 tablets). The result-
ing categories were used as baseline scores in a Van Elteren
142 S. Kennedy et al.
test to compare post-treatment medication usage between
Data from the exit questionnaire were analysed using
Mann—Whitney tests to establish any differences between
groups. A power analysis was completed using a between
group minimal clinically important difference (MCID) of 2.5
points for the RMDQ,31at an alpha of 0.05 and power of 90%.
Forty-eight patients were recruited and randomized into
groups: see Fig. 1.32Outcome data were obtained from 94%
of participants at the end of treatment; at 3 months follow
up this had reduced to 83%. Reasons given for not complet-
ing treatment were: no benefit gained, no time available,
and work commitments.
Table 2 shows distribution of age, gender, pain distribution,
work status, days off work and medication intake, whilst
Table 3 shows baseline values for all outcome measures. No
significant differences between the two groups were iden-
tified; however the placebo group had higher scores on VAS
and RMDQ at baseline, thus supporting the use of ANCOVA
Pain distribution (%)
Simple back pain
Work status (%)
Health care usage (%)
The flow of the trial according to the CONSORT statement.32
Acupuncture for acute low back pain143
Outcome measure scores expressed as mean±S.E.M. values
Verum acupuncture (mean±S.E.M.)
Sham acupuncture (mean±S.E.M.)
Days off work
Medication intake (tablets per day)
12.7 ± 1.1
56.2 ± 5.7
76.4 ± 4.7
11.1 ± 4.5
4.2 ± 0.6
6.0 ± 1.0
27.3 ± 4.9
40.71 ± 6.1
13.9 ± 5.3
1.0 ± 0.3
5.0 ± 1.0
26.5 ± 5.2
33.3 ± 5.7
12.8 ± 1.1
62.6 ± 4.0
73.8 ± 4.1
7.5 ± 2.3
5.3 ± 0.8
7.0 ± 1.3
36.3 ± 6.1
52.5 ± 6.1
10.9 ± 4.1
4.2 ± 0.6
7.7 ± 1.5
40.7 ± 6.2
51.7 ± 5.8
The estimated marginal mean differences in all outcome
measures at the end of treatment and follow up (adjusted
for baseline values) are summarized in Table 4. There was
no significant difference between groups on the RMDQ over
Pain was measured as average pain and worst pain. There
was no significant difference between groups at the end of
treatment for average pain or worst pain (p>0.05); how-
ever, at follow up there was a trend towards a greater
analgesic effect for average pain in the verum acupuncture
group (average VAS: estimated marginal mean difference
from baseline, 10.6, 95% CI −0.41 to 25.3, p=0.152). In the
case of worst pain, such differences were found to be sta-
tistically significant at the 3 months follow up (worst VAS:
estimated marginal mean difference from baseline, 18.7,
95% CI 1.5—36.0, p=0.034).
Results for medication intake showed that the majority
of patients were taking some form of analgesic medica-
tion for LBP at the start of treatment (n=44; 92%). At
the end of treatment, subjects in the verum acupuncture
group were taking significantly fewer doses (tablets per day)
of medication (1.0±0.3; mean±S.E.M.) than the placebo
group (4.2±0.6). This difference remained significant after
allowance for pretreatment differences in medication usage
(p<0.05, Van Elteren test).
Patients received a mean of 5.7 treatments. There was
a significant difference between groups in the number of
treatments received (Mann—Whitney test, p=0.001). The
acupuncture group received more treatments (6.3±1.5;
mean±S.D.): 11 patients in this group received more than
six treatments, compared to none in the placebo group
(5.2±1.4). In exploring the effect of this on each outcome
measure there was only weak evidence (p=0.075) for a posi-
tive relationship between RMDQ at the follow-up period and
the number of treatments received; however allowance for
this by using the number of treatments as a covariate in the
analysis did not substantially affect the conclusions.
The current data were used to calculate numbers required
to detect significant differences for pain (average VAS) and
RMDQ between groups. For average pain, using an estimated
baseline score for each outcome measure, and the between-group difference values plus statistical analyses of these values
This table shows the estimated marginal mean values for verum and placebo acupuncture adjusted for the initial
VerumPlacebo Placebo-verumStatistical analysis of
differences (p value)
RMDQ end of treatment 6.1±1.0
95% CI, 5.0—8.9
95% CI, 2.7—7.4
95% CI, 4.1—8.0
95% CI, 5.3—10.0
95% CI, −1.8—3.7
2.6±1.6 follow up
95% CI, −0.7—5.9
95% CI, −8.7—20.9
95% CI, −4.1—25.3
95% CI, −4.8—29.7
95% CI, 1.5—36.0
3 months 0.119
VAS average end of treatment 28.8±5.2
95% CI, 18.3—39.2
95% CI, 17.9—38.6
95% CI, 24.4—45.3
95% CI, 28.5—49.2
VAS worst end of treatment40.4±6.1
95% CI, 28.2—52.5
95% CI, 20.8—45.3
95% CI, 40.7—65.0
95% CI, 39.6—64.0
Significant differences between groups are in bold for worst VAS, the acupuncture group demonstrated significant hypoalgesia at follow
144 S. Kennedy et al.
group (%) (n)
I would have it again
I would recommend it to others
Overall I was satisfied with my care
I didn’t recover as well as I hoped
Physiotherapy was a complete waste of time
I enjoyed coming for physiotherapy
I feel she listened to what I had to say
I was given good advice about my back
Table 5 (Continued)
group (%) (n)
I was given a chance to ask questions
aPatients were asked whether they had received acupuncture
yes/no; or whether they had received advice yes/no.
within group S.D. of 30 points, an MCID between groups of
20, alpha of 0.05 and power at 90%, a total of 56 subjects (28
in each arm) would need to be recruited. For RMDQ, using
the same power and alpha level, an estimated within group
S.D. of four points, and an MCID between groups of 2.5, a
total of 120 subjects (60 in each arm) would be needed.
Credibility of placebo acupuncture
Results of the exit questionnaire are summarised in Table 5.
All patients who offered an opinion (22 placebo group,
23 verum group) believed they had received acupuncture,
supporting the credibility of non-penetrating sham acupunc-
Results from this study indicate that a larger trial would
require 60 participants in each arm in order to have the
power to demonstrate statistically significant changes in
both pain and function in acute LBP. Return to function is
of primary importance in LBP and should be considered the
we used an RMDQ between group difference value of 2.5
points as recommended by Roland and Fairbanks31and an
S.D. of four points derived from our pilot data.
This study has also demonstrated the feasibility of a
methodologically rigorous, sham-controlled trial in a clin-
ically appropriate setting (a busy hospital outpatient clinic)
intervention was carried out as part of the normal workload
of treating physiotherapists, and patients accepted comple-
tion of a range of validated outcome measures with minimal
drop out at the 3 months follow up (placebo 12%; verum 4%).
In a main trial we would anticipate recruiting multiple phys-
iotherapy departments across Northern Ireland but would be
more prudent and estimate a drop out of 20%.
Finally this study is the first to use the Park Sham
Device in acute LBP patients, and thus adds to the valid-
ity already demonstrated in healthy adults and those with
stroke.5,7Furthermore verum acupuncture produced a clin-
ically important (for pain and function33,34) and statistically
significant (for worst pain) analgesic effect compared to
non-penetrating sham acupuncture, at 3 months follow up.
Coupled with this effect was a significant reduction in med-
ication intake for the verum group over the course of
Acupuncture for acute low back pain145
treatment. No significant effects were observed for func-
tion, although there was a trend for a greater (clinically
important) improvement in the verum group at follow up.
Previous studies have been unable to disentangle spe-
cific from non-specific placebo effects, as all such trials
used penetrating needles23,35,36which may produce physi-
ological effects.37,38It was interesting the specific effect
shown here increased over time to its greatest values at
the 3 months follow up, and although difficult to interpret,
similar ‘delayed’ analgesic effects have been observed in
other studies23,39at a 3 months and at 24 months follow up,
Treatment dose was not controlled in this trial, as we
were interested in any differences in uptake of treatments
between groups. Although patients in the verum group
received more treatment than those in the sham group,
results for pain or function. Whilst reasons for such differ-
ences are unclear, both therapists and patients could have
influenced this; factors explaining these differences should
be explored in future trials.
Apart from being underpowered, another limitation of
asked to record in a daily diary the type of medication,
the dose in mg, and the number taken per day. However,
compliance was poor and thus data were extracted from
the therapists’ charts which indicated only the number of
tablets per day. In a future trial it would be more useful to
record detailed medication intake prior to each treatment,
or provide patients with a prompt for a daily entry (e.g.
In conclusion, this pilot has demonstrated the feasibility
of a randomized controlled trial in this area, using RMDQ as a
primary outcome, and secondary outcomes of pain and med-
ication intake. Results of such a trial would address the lack
of high quality evidence for the specific effect of acupunc-
ture in acute LBP, as highlighted by two recent systematic
Dr Park developed the Park Sham Device and supplied the
samples for use in the study.
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