15250-m-cuypers

69 Decision aid development and usability testing 4 active phrasing) 22 23 . Readability and comprehensibility was later assessed by an expert in medical communication from the initiating hospital, who was not involved to the further development of the DA. Stage 4: Development of explicit values clarification exercises For use in patient decision aids, IPDAS defines that values clarification exercises (VCEs) should ‘help patients to clarify and communicate the personal value of options’, in order to ultimately increase congruence between personal preferences and the selected treatment option 24 . However, without clear design guidelines for VCEs a variety of exercises have been developed with little knowledge about which features actually work best 25-27 28 . A recent review suggests that VCEs should at least include trade-offs between option attributes in order to encourage value congruent decision-making 29 . Therefore, from all topics covered in the DA, those topics that differentiate between treatments were selected to create explicit VCEs. To present these topics as a trade-off, statements were presented in such way that an answer to each statement was related to a (type of ) treatment. VCEs were developed within the development team and reviewed from the perspective of the disciplines present in the development team (urology, psychology, engineering design). After consensus by the development team, VCEs were added to the DA. The content and phrasing of the VCEs was further evaluated during usability testing. Stage 5: Usability testing After completion of the first version of the adjusted DA a usability test was conducted among patients and care providers (N=11). Setting and participants Participants for usability testing were recruited in the initiating hospital in the southern region of The Netherlands, by the clinicians from the development team. Four urologists (not involved to the DA development), two oncology nurses, one radiation oncologist and four Pca patients with recent experience in Pca treatment decision making agreed to participate in usability testing. All patients were between 55 and 65 years of age and within six months of Pca diagnosis. Patients with experience in the decision situation were selected because they were expected to be better able to imagine the situation of just having received a Pca diagnosis 30 . IPDAS therefore also requires that DA testing is performed by experienced patients 6 . Care providers were included in this usability test to ensure the DA content and usability would match their usual routines and their experiences with patients facing Pca treatment decisions. Also, care providers’ review during development is required by IPDAS 6 . All care providers included in usability