Table 2 Description of Study Measures

 Behaviors (primary outcomes)

FC: Self-report of whether they shared their genetic test result with at least one family member for the first time or followed up with family (e.g., gave them relevant information, answered questions, etc.) [59]

CRM: Self-report risk management behaviors verified via medical records review to determine if they are congruent with current NCCN guidelines [34, 60, 61]

 Awareness and engagement in behavior

FC: Several items asking whether they have thought about sharing, chosen to share, and attempted to share and follow-up with family members (response options yes, no, unsure) [62]

CRM: Single question asking them to pick one of seven statements that best describes where they are in following medical guidelines [63]

 Capability (objective knowledge)

Both: Inherited cancer testing and treatment knowledge (scores range from 0 to 12 correct) [64, 65]

 Capability (understand how to take action, plan & remember)

FC: Likert scale questions (know actions to take, know family members at high risk, clear plan of how, find behavior easy, can remember to act) [62, 66,67,68,69,70,71,72]

CRM: Likert scale questions (know actions to take, clear plan of how, find behavior easy, remember to act) [62, 66, 68, 72]

 Opportunity (social influences and environmental constraints/facilitators)

FC: Items asking if they think each relative would want to know the result (yes, no, unsure); Likert scale questions-normative influences of healthcare providers and family members; available resources (material resources, contact information, nothing preventing them from communicating) [62, 66,67,68,69,70,71,72,73,74,75]

CRM: Likert scale questions-normative influences of healthcare providers, family/friends; available resources (insurance/money to cover cost, hospital or medical center, nothing preventing) [62, 68, 69, 72, 76,77,78,79]

 Motivation (feelings and beliefs about the behavior)

FC: Likert scale questions (feelings about FC, important/useful, sense of duty to share information, anticipated outcomes of FC) [62, 66,67,68,69,70,71,72,73, 80, 81]

CRM: Likert scale questions (feelings about guidelines, important/useful, anticipated outcomes of following guidelines) [62, 66, 69, 71,72,73, 80, 82]

 Acceptability

Intervention is satisfactory and agreeable - Acceptability of Intervention Measure (AIM) – 4-item Likert scale [83]

 Appropriateness

Perceived fit, relevance, usefulness - Intervention Appropriateness Measure - 4-item Likert scale [83, 84]. Additional questions assessing perceived usefulness of various resources included in the respective interventions.

 Exposure

Electronic data will capture what resources are viewed or downloaded and time spent on the website. Surveys will ask which resources they used and shared with family and healthcare providers.

 Reach

RE-AIM steps for reporting on Reach [85] will be used – including extent to which participants and those who access resources as part of the interventions are representative based on key sociodemographic and clinical variables.

 Implementation processes and cost

A systematic, theory-based approach described by Bunger et al. [86] will be used for tracking implementation processes (e.g., answering questions about the interventions, sending out email updates/reminders, etc.) and time involved maintaining the interventions. Costs can then be calculated, including time and website maintenance.

 Sociodemographic and clinical factors

1) Age, education, household income, marital/partner status, rural-urban community area code, living biological family members, health insurance status and type; 2) Personal/family history of cancer, stage of diagnosis; 3) Health Literacy [87]; 4) Gene with the pathogenic/likely pathogenic variant (verified by genetic test report); 5) Recommendations of their healthcare provider regarding behaviors

 Family communication

Likert questions from Communication subscale of the McMaster Family Assessment Device [88]

 MICRA

Uncertainty, distress, and positive aspects of genetic test results measured by the Multi-Dimensional Assessment of Cancer Risk Assessment (MICRA), Multiple Likert type items [89]