Table 1.

Attributes and levels used in conjoint analysis

Attribute	Level
Accessibility	1. Portal can be accessed via a computer (laptop and/or desktop)
	2. Portal can be accessed via a tablet (for example iPad)
	3. Portal can be accessed via a smartphone (for example iPhone)
Login	1. Username and password (least secure)
	2. DigiD with SMS verification (secure)
	3. Username, password and SMS verification (secure)
Interoperability	1. No export of data
	2. Export of data to non-interoperable format (e.g. PDF)
	3. Export of data to interoperable format (e.g. Continuous Care Document)
Availability of information	1. Direct publication of information
	2. Information delayed until discussed with provider
	3. Available after 2 weeks independent if information has been discussed with provider
Content	1. Reports and basic information (e.g. medication overviews and allergies)
	2. Reports and basic information and professional summary
	3. Complete uncensored medical file
Number of providers	1. Contains information from one provider (e.g. hospital or general practitioner)
	2. Contains information from multiple providers (e.g. hospitals and general practitioner)
Patient-provider communication	1. No possibility to ask online questions
	2. Possibility to ask questions about medical data or previous visits in the portal
	3. Online in-patient consult