Table 2.

Sources and text for all items except demographic variables and treatment phase (translated from Dutch).

Construct	Source	Item(s)	Response options
Health status	[42]	Overall, my health status is...	Poor to very good
Expected utility of the platform	[29,41]	How useful do you think kanker.nl will be for you?	Not at all to very useful
Prior negative experience	[23]	My experiences with privacy infringement on personal health can be described as...	Not at all negative to very negative
Privacy concern	[23]	I believe that submitting health information on the Internet is...	Highly advisable/not advisable at all
		Health information on the Internet, once submitted...	Will not be abused at all/will be abused for sure
Intention to share information	Self-developed	We are currently designing the privacy settings for Kanker.nl, for each piece of information, please indicate which group you would like to share it with	Only with personal contacts/only with members of the website/with all website visitors