ISRCTN25267500: Informed Shared Decision Making In Multiple Sclerosis Immunotherapy (ISDIMS). A randomised controlled trial to investigate the effects of an evidence-based decision aid on decision-making about immunotherapy in multiple sclerosis

To evaluate the effects of an evidence-based patient decision aid (DA) on multiple sclerosis (MS) immunotherapy. Two hundred and ninety-seven MS patients who were considering or reconsidering immunotherapy participated in a randomized community-based controlled trial in Germany. An intervention group (IG) received the DA and a control group (CG) received standard information. Primary outcome measure was the match between the patient's preferred and actual roles during consultation with the physician. Secondary end-point was treatment choice. The course of the decision-making process and patients` evaluation of the decision were also evaluated. Data were collected at baseline, after receiving the information, after consultation with the physician and 6 months after baseline. The percentage of preference matches did not differ between groups (IG 49%, CG 51%, P = 0.71). There were no differences in immunotherapy choices between groups. IG patients temporarily became more critical of immunotherapy and rated the information as significantly more helpful. Although the intervention led to intensified processing of the information it affected neither the roles adopted in physician-patient encounters nor the immunotherapy choices made. Providing patients with balanced information may not be sufficient to alter the decision-making process.