Original scale items
1. It is easy for me to take my medicine on time.
2. It is easy for me to ask my doctor questions about my medicine.
3. It is easy for me to ask my pharmacist questions about my medicine.
4. It is easy for me to understand my doctor’s instructions for my medicine.
5. It is easy for me to understand my pharmacist’s instructions for my medicine.
6. It is easy for me to understand instructions on medicine bottles.
7. It is easy for me to get all the information I need about my medicine.
8. My medicines are easy to take.
9. It is easy to remember to take all my medicines.
10. It is easy for me to set a schedule to take my medicines each day.
11. It is easy for me to learn how to take my medicines.
12. It is easy for me to take my medicines every day.
13. If I miss a dose of my medicine, it is easy for me to know what to do.
14. I am confident that I am able to deal with any unexpected health problems.
15. If I don’t understand something, it is easy for me to ask for help.
16. I know that I will be able to actively participate in decisions about my health.
17. It is easy for me to take my medicines the way I am supposed to.
18. Taking my medicines is part of my daily routine.

Items in plain text were eliminated in the first principal components factor analysis due to low factor loadings. The single item in italics was eliminated upon a second principal components factor analysis due to low factor loadings on both factors (<0.30 on both factors). Bolded items are retained in final MUSE Scale