Table 3.

System Usability Scale (SUS) scores related to a long-term interaction established through the electronic informed consent prototype.

Question number	Question	Iteration 1, mean (SD)a	Iteration 2, mean (SD)b	Iteration 3, mean (SD)c
1	I think that I would like to use this system frequently.	3.5 (0.85)	4.4 (0.70)	(0.82)
2	I found the system unnecessarily complex.	3.1 (0.88)	2.3 (1.3)	2.1 (0.88)
3	I thought the system was easy to use.	3.3 (1.1)	4.1 (0.88)	3.7 (0.82)
4	I think that I would need the support of a technical person to be able to use this system.	2.7 (1.4)	2.1 (1.3)	2.3 (1.1)
5	I found the various functions in this system were well integrated.	3.6 (1.1)	3.5 (0.85)	4.1 (0.57)
6	I thought there was too much inconsistency in this system.	2.3 (1.2)	2.1 (1.2)	1.7 (0.68)
7	I would imagine that most people would learn to use this system very quickly.	2.7 (1.1)	3.1 (1.2)	3.7 (0.95)
8	I found the system very cumbersome to use.	2.6 (1.1)	2.0 (0.82)	2.0 (0.67)
9	I felt very confident using the system.	3.5 (1.1)	3.6 (0.70)	3.7 (0.68)
10	I needed to learn a lot of things before I could get going with this system.	3.1 (1.2)	2.1 (1.5)	2.6 (1.3)

^aTotal score: mean 57.5 (SD 19.5).

^bTotal score: mean 70.3 (SD 17.3).

^cTotal score: mean 71.3 (SD 16.1).