Because in this study questionnaires only revealed a small part of the barriers and facilitators, time

spared only using questionnaires was outweighed by the limited output. We estimate that overall, interviews seemed most efficient in terms of cost and benefits. Time spent to recruit this website participants was in favour of the interviews as we only needed 15 participants. Furthermore, the time needed to prepare and execute the focus groups and interviews was similar, although two researchers were needed to guide the focus groups. We estimate that the time to analyse the output was similar for both methods. Conclusions We conclude that focus groups, CB-5083 manufacturer interviews and questionnaires with intended users can all Crenigacestat reveal a substantial number of barriers and facilitators to use a new genetic test. In this study, interviews and focus groups both revealed a higher number of items that can influence the use of the genetic test than questionnaires. Interviews and focus groups may be combined to reveal all potential barriers and facilitators in a study population. For the application of a new genetic test in practice, our findings suggest that interviews constitute the most appropriate method as the total of revealed barriers plus facilitators divided by the number of participants was highest. This conclusion may be valid for other health-related research products as well. Acknowledgments We thank

Foundation Institute GAK (Hilversum, the Netherlands) for funding this study. We would further like to thank the participating nursing schools (ROC ASA, ROC Amsterdam and Hogeschool van Amsterdam) and students for their collaboration in this study. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium,

provided the original author(s) and the source are credited. Appendix 1 Table 4 Description of literature items and new items mentioned by student nurses during focus group sessions, interviews Terminal deoxynucleotidyl transferase and questionnaires Domain Explanation of items Expected use of genetic test (results) on HE  1. Preventive measuresa 1. Participant would use the test for taking measures to prevent the development or worsening of HE by minimising exposure or maximising skin care.  2. Test is redundant: not decisive/definite to acquire HEa 2. Participant would not use the test because he/she thinks it is redundant. A positive test will not mean you certainly acquire HE. A negative test does not guarantee you will not acquire HE.  3. Extrapolating to take preventive measures for family or childrenb 3. Participant would use the test because the test results indirectly provide information to family members or children, can be used to identify their susceptibility for HE and can possibly be a reason to take preventive measures.  4. Test result will only lead to more (un)careful preventive behaviourb 4.