Acupuncture for irritable bowel syndrome – an exploratory randomised controlled trial
- Julie A Reynolds, postgraduate researcher1,
- J Martin Bland, professor of health statistics1,
- Hugh MacPherson, senior research fellow2
- 1Department of Health Sciences University of York, UK
- 2Department of Health Sciences, University of York, UK & Foundation for Traditional Chinese Medicine York, UK
Background The evidence on the effectiveness of acupuncture for irritable bowel syndrome (IBS) is inconclusive. However, many patients with IBS are self referring for acupuncture, therefore it is of interest to know whether acupuncture is effective or not. The aim of this study was to establish variability in the primary outcome measure to enable a sample size to be calculated for a full scale trial, and to explore feasibility and design criteria.
Methods A pragmatic randomised controlled trial compared 10 sessions of acupuncture plus usual GP care with usual GP care alone. Thirty patients were recruited from four GP databases in Birmingham, UK, and randomised one-to-two to acupuncture or usual care alone. The primary outcome was the IBS Symptom Severity Score (SSS) at three months (maximum score 500). Analysis was by intention-to-treat, and multiple imputation was used for missing data.
Results From the databases, 189 patients with IBS were identified, of whom 30 were eligible and consented to randomisation. At three months, a statistically and clinically significant difference between groups of 138 points (SD 90) in favour of acupuncture was observed on the IBS SSS (95% CI: 66 to 210; P=0.001) using multiple imputation. For a full scale trial, we estimate that a sample size of 108 patients per arm is required, based on a minimum clinically significant change of 50 points, drawn from a primary care population of 140 000.
Conclusions We established the feasibility of a full scale trial, successfully recruiting patients and calculating the sample size required. The results of our pilot analysis suggest that more definitive research into acupuncture for IBS is merited. A pragmatic trial design will not be able to distinguish between acupuncture specific effects and placebo effects; however, it is the design of choice to determine cost effectiveness.