Improving Shared Decision Making in Vascular Surgery: A Stepped Wedge Cluster Randomised Trial

Different treatment options are available and feasible for various vascular surgical disorders. Hence, vascular surgery seems an area par excellence for shared decision making (SDM), in which clinicians incorporate the patient's preferences into the final treatment decision. However, current SDM levels in vascular surgical outpatient clinics are below expectations. To improve this, different decision support tools (DSTs) have been developed: online patient decision aids, consultation cards, and decision cards.This stepped wedge cluster randomised trial was conducted in 13 Dutch hospitals. Besides the developed DSTs, training on how to apply SDM during the clinician patient encounter was used in this study. Data were obtained via questionnaires and audio recordings. The primary outcome was the OPTION-5 score, an objective tool to assess the level of SDM, expressed as a percentage of exemplary performance. Main secondary outcomes were patients' disease specific knowledge, consultation duration, and treatment choice. Factors influencing OPTION-5 scores were studied using linear regression analysis.Included in the study were 342 patients with an abdominal aortic aneurysm (AAA; n = 87), intermittent claudication (IC; n = 143), or varicose veins (VV; n = 112). Audiotapes of 395 consultations were analysed. Overall the mean OPTION-5 score significantly improved from 28.7% to 37.8% (mean difference 9.1%, 95% CI 6.5% - 11.8%) after implementation of the DSTs. Also, patient knowledge increased significantly (median increase: 13%, effect size: 0.13, p = .025). The number of patients choosing non-surgical treatment choices increased, with 21.4% to 28.8% for patients with AAA and doubled (16.0% to 32.0%) among patients with IC. For surgeons, the SDM training and for patients the decision aid significantly and independently increased OPTION-5 scores (p < .001 and p = .047, respectively).Introducing DSTs improves the level of shared decision making in vascular surgery, improves patient knowledge, and shifts their preference towards more non-surgical treatments. The SDM training for clinicians and the decision aid for patients appeared the most effective means of improving SDM.NTR6487.