Use of complementary therapies is associated with expectations of treatment effectiveness among persons with multiple sclerosis.

Background Complementary therapies (CTs) are widely used among persons with multiple sclerosis (MS). Patients' expectations of treatment effectiveness are linked to CT use in the general population. However, little is known about how such expectations vary among people with MS or whether they are associated with CT use.Objectives To identify expectation-based clusters among adults with MS, describe their characteristics and assess associations with current CT use.Methods We conducted a cross-sectional analysis of Swiss MS Registry follow-up survey data collected between October 2022 and October 2023, exploring expectations regarding manual, mind-body, natural product-based and dietary therapies. K-means clustering was applied to eight variables assessing participants' expectations of each therapy's effectiveness for physical and psychological symptoms. Clusters were described, and associations with current CT use were analysed using log-binomial regression.Results A total of 753 participants were classified into three expectation clusters: low (20.3%), moderate (47.6%) and high (32.1%). The low-expectation cluster included more individuals with progressive MS, severe gait disability and lowest CT use. Expectation clusters were significantly associated with current CT use. In unadjusted analyses, inclusion of the cluster variable significantly improved model fit (likelihood ratio test (LRT)=31.25, p<0.001), and participants in the moderate-expectation and high-expectation clusters were more likely to use CT compared with the low-expectation cluster (relative risk (RR) 1.60, 95% CI 1.26 to 2.04; RR: 1.80, 95% CI 1.42 to 2.30). After adjustment, the association remained significant (LRT=29.01, p<0.001), with higher likelihoods of CT use in the moderate-expectation and high-expectation clusters (adjusted RR: 1.58, 95% CI 1.24 to 2.00; RR: 1.80, 95% CI 1.41 to 2.30, respectively). Sensitivity analyses using an alternative CT outcome variable yielded consistent results.Conclusions Expectation profiles are independently associated with CT use in MS. Addressing misalignments between patient expectations and evidence may help promote informed, evidence-based decision-making about CTs.