Zsa Zsa Weerts

Cost-effectiveness of peppermint oil in IBS 201 8 small-intestinal release peppermint oil may be considered cost-effective compared to placebo during an eight-week treatment, from a societal perspective at a conservative WTP-threshold of €10.000 per QALY. However, there is uncertainty surrounding the incremental cost-effectiveness ratios (ICERs). At a lower and highly conservative WTP- threshold of €1.000 per QALY, peppermint oil and placebo have an equal chance of being cost-effective. Sensitivity analyses showed similar results indicating uncertainty surrounding the cost-effectiveness of peppermint oil with the exception of the analyses using abdominal pain responder according to FDA-definition, and costs from a healthcare perspective. In these cases, peppermint oil has a much higher probability of being cost-effective compared to placebo. IBS is highly prevalent and one of the most expensive conditions in gastroenterology. 27 We recently demonstrated that peppermint oil is a moderately effective treatment in patients with IBS, decreasing abdominal pain, discomfort, and IBS-symptom severity. 9 Although non-significant, small-intestinal release peppermint showed an abdominal pain response rate (FDA-defined) of 12.4%, which is numerically comparable to studies reporting statistically significant differences between linaclotide, 28 plecanatide 29 and tenapanor 30 versus placebo. These findings further warrant a trial-based economic evaluation such as the current study. Peppermint oil is available as an OTC drug without reimbursement from healthcare insurance in many countries. Peppermint oil capsules are relatively inexpensive and this study indicates that they are likely cost-effective, showing that its use can be justified by the (albeit modest) gains in health-related QoL and cost-savings. Moreover, in light of its favorable adverse event profile, and the fact that no pharmacological treatment thus far has been able to cure IBS or improve stringent outcomes in more than half of the patients investigated, small-intestinal release peppermint oil can be a worthwhile treatment option. Peppermint oil seems particularly suited for primary care or as an initial step in therapy since more than half of patients were recruited in this setting. Our findings are further supported by preliminary model-based study suggesting cost- effectiveness of peppermint oil. 31 Other treatments with a high probability of being cost- effective as a treatment for IBS are anti-depressants, the low FODMAP diet, and cognitive behavioral therapy. 27 No direct comparisons can be made at this point due to different study designs and patient populations. The ICER of eight weeks of peppermint oil treatment was dominant, indicating cost savings with a small health related QoL gain with the bootstrap analysis showing uncertainty surrounding the ratio. This short-term evaluation might underestimate cost-