Cost-effectiveness of acupuncture for irritable bowel syndrome: findings from an economic evaluation conducted alongside a pragmatic randomised controlled trial in primary care

Background: There is insufficient evidence to determine whether acupuncture is a cost-effective treatment for irritable bowel syndrome. The objective of this study is to assess the cost-effectiveness of acupuncture as an adjunct to usual care versus usual care alone for the treatment of Irritable Bowel Syndrome (IBS). Methods: Cost-utility analysis conducted alongside a pragmatic, multicentre, randomised controlled trial. 233 patients with irritable bowel syndrome were randomly allocated to either acupuncture plus usual care, or usual care alone. Cost-effectiveness outcomes are expressed in terms of incremental cost per quality adjusted life year (QALY) at one year after randomisation. Costs were estimated from the UK National Health Service perspective for a time horizon of one year. Cost-utility ratios were estimated based on complete case analysis for the base case analysis, where only patients with available EQ-5D and cost data were included. Sensitivity analyses comprised a multiple imputation approach for missing data and a subgroup analysis for the more severe cases of IBS. Results: The base case analysis showed acupuncture to be marginally more effective than usual care (gain of 0.0035 QALYs, 95% CI: -0.00395 to 0.0465) and more expensive (incremental cost of 218 pound per patient (95% CI: 55.87 to 492.87) resulting in an incremental cost-effectiveness ratio of approximately 62,500 pound. Sensitivity analysis using multiple imputation for missing data resulted in acupuncture appearing less effective and more costly than usual care, so usual care is dominant. Subgroup analysis selecting the most severe cases of IBS (Symptom Severity Score of over 300) suggested that acupuncture may be a cost-effective treatment option for this group, with a cost-per-QALY of 6,500 pound. Conclusions: Acupuncture as an adjunct to usual care is not a cost-effective option for the whole IBS population; however it may be cost-effective for those with more severe irritable bowel syndrome.