Table 1.

Design parameters used in developing the REDCap intervention.

Category and required design parameter			REDCap featuresa
Participant access to intervention
	Intervention accessible through links sent by email. Reminder emails sent with the deadlines for finishing the module.	REDCap generated unique URLs for each participant when sent by Automatic Survey Invitation using Smart Variables. Dates were piped into the email text.
	Participants have unique logins to access their information. Participants can save, leave, and return to the website.	Enabled Save & Return in the Survey Settings
	Data must be kept in a secure, HIPAAb compliant database.	REDCap provided a secure web interface and included multiple features to support HIPAA compliance. Both the website and database were housed on secure servers maintained by the researcher’s institution.
Intervention design
	Educational material able to be delivered by text and videos.	Used descriptive text fields, including in-line video
	Self-led exercises present participants’ prior responses for reflection and goal-setting.	Previous responses were piped into descriptive text for participant review.
	The length of intervention can be shortened if the participant's therapy start date is less than 3 weeks away. Module start and completion dates are otherwise used to enable future modules and trigger emails to send.	Therapy date was entered in the participant set up instrument. Start and completion dates were captured as validated date text variables using the @HIDDEN-SURVEY Action Tag. Conditional logic in Automatic Survey Invitations using datediff calculations and indicator variables sent emails. The Survey Queue was used when there was not a lag in time between instruments.
	Intervention modules are disabled after a period of time to ensure that they are completed in order.	Time Limit for Survey Completion option was used in the Survey Settings.
	Hyperlinks to voice and psychological health tips are embedded in the intervention check-ins. Menu and navigation have hyperlinks to resources including the study FAQ, program references, and supplemental mental health resources.	Hardcoded hyperlink embedded in a survey field connected to another REDCap project using the project’s public link. Because a left-hand menu bar was not possible in REDCap and layout was limited to one center panel of text, the menu links were listed in a descriptive text variable at the bottom of each survey page.
Study execution
	The intervention can adapt to changing participant inputs throughout participant, such as: Updates in contact information. Changing dates of scheduled medical treatment, which affect study participation duration.	A project instrument was used for participant setup to enter dates used for Automatic Survey Invitations and manage participant information piped into the intervention. An email variable was set as the survey-specific email invitation field in the Survey Settings instead of using the Survey Distribution Tools to allow for updates over time and ease in participant set up. Automatic Survey Invitations were triggered to send the day before the enabling date to allow for date changes during the study, but the researcher could update and retrigger emails if needed using the Survey Invitation Log.
	The intervention moves through modules in sequence.	Default use of the Survey Queue allowed linear progression through surveys.
	Participants cannot go backwards and change answers, which is important for data integrity.	Instrument Survey Settings were set to prevent return to and modification of completed responses.
	Website collects date and time stamps for all responses.	REDCap captured and could report timestamps for survey start, completion, and all responses.

^aREDCap-specific terms are in italics.

^bHIPAA: Health Insurance Portability and Accountability Act.