Irritable bowel syndrome (IBS) is a common, costly, and difficult to
treat disorder that impairs health-related quality of life and work
productivity. Evidence-based treatment guidelines have been unable to
provide guidance on the effects of acupuncture for IBS because the only
previous systematic review included only small, heterogeneous and
methodologically unsound trials.
The primary objectives were to assess the efficacy and safety of
acupuncture for treating IBS.
MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE,
the Cumulative Index to Nursing and Allied Health, and the Chinese databases
Sino-Med, CNKI, and VIP were searched through November 2011.
Randomized controlled trials (RCTs) that compared acupuncture with
sham acupuncture, other active treatments, or no (specific) treatment, and
RCTs that evaluated acupuncture as an adjuvant to another treatment, in
adults with IBS were included.
Data collection and analysis
Two authors independently assessed the risk of bias and extracted
data. We extracted data for the outcomes overall IBS symptom severity and
health-related quality of life. For dichotomous data (e.g. the IBS Adequate
Relief Question), we calculated a pooled relative risk (RR) and 95%
confidence interval (CI) for substantial improvement in symptom severity
after treatment. For continuous data (e.g. the IBS Severity Scoring System),
we calculated the standardized mean difference (SMD) and 95% CI in
post-treatment scores between groups.
Seventeen RCTs (1806 participants) were included. Five RCTs compared
acupuncture versus sham acupuncture. The risk of bias in these studies was
low.We found no evidence of an improvement with acupuncture relative to sham
(placebo) acupuncture for symptom severity (SMD-0.11, 95%CI
−0.35 to 0.13; 4 RCTs; 281 patients) or quality of life (SMD =
−0.03, 95%CI −0.27 to 0.22; 3 RCTs; 253 patients).
Sensitivity analyses based on study quality did not change the results. A
GRADE analysis indicated that the overall quality of the evidence for the
primary outcomes in the sham controlled trials was moderate due to sparse
data. The risk of bias in the four Chinese language comparative
effectiveness trials that compared acupuncture with drug treatment was high
due to lack of blinding. The risk of bias in the other studies that did not
use a sham control was high due to lack of blinding or inadequate methods
used for randomization and allocation concealment or both. Acupuncture was
significantly more effective than pharmacological therapy and no specific
treatment. Eighty-four per cent of patients in the acupuncture group had
improvement in symptom severity compared to 63% of patients in the
pharmacological treatment group (RR 1.28, 95% CI 1.12 to 1.45; 5
studies, 449 patients). A GRADE analysis indicated that the overall quality
of the evidence for this outcome was low due to a high risk of bias (no
blinding) and sparse data. Sixty-three per cent of patients in the
acupuncture group had improvement in symptom severity compared to
34% of patients in the no specific therapy group (RR 2.11,
95% CI 1.18 to 3.79; 2 studies, 181 patients). There was no
statistically significant difference between acupuncture and Bifidobacterium
(RR 1.07, 95% CI 0.90 to 1.27; 2 studies; 181 patients) or between
acupuncture and psychotherapy (RR 1.05, 95% CI 0.87 to 1.26; 1
study; 100 patients). Acupuncture as an adjuvant to another Chinese medicine
treatment was significantly better than the other treatment alone.
Ninety-three per cent of patients in the adjuvant acupuncture group improved
compared to 79% of patients who received Chinese medicine alone (RR
1.17, 95% CI 1.02 to 1.33; 4 studies; 466 patients). There was one
adverse event (i.e. acupuncture syncope) associated with acupuncture in the
9 trials that reported this outcome, although relatively small sample sizes
limit the usefulness of these safety data.
Sham-controlled RCTs have found no benefits of acupuncture relative
to a credible sham acupuncture control for IBS symptom severity or
IBS-related quality of life. In comparative effectiveness Chinese trials,
patients reported greater benefits from acupuncture than from two
antispasmodic drugs (pinaverium bromide and trimebutine maleate), both of
which have been shown to provide a modest benefit for IBS. Future trials may
help clarify whether or not these reportedly greater benefits of acupuncture
relative to pharmacological therapies are due entirely to patients’
preferences for acupuncture or greater expectations of improvement on
acupuncture relative to drug therapy.