Table 2 Father Engagement Interview Themes and Illustrative Quotes Mapped to CFIR Domains and Impact on Intervention Design: Intervention Characteristics

Relative Advantage

Stakeholders’ perception of the advantage of implementing the intervention versus an alternative solution

Perceived advantages of the proposed intervention:

i. Unique father-specific content

ii. Easy and convenient delivery

iii. Individual (versus group) interaction and instruction

i. “I think having resources available for dads might make it more—might normalize more that dads are also involved in these decisions about parenting. That might increase dad involvement.”

ii. “Getting more information and coming to the house is much easier than figuring out on your own where to go and who to talk you to.”

iii. “To me, why I like it is it separates me from paying $500 to be amongst a group of 14 other people I don't know. That would shut me down from being as open and honest as I really want to be and need to be to learn. That’s a huge selling point in my opinion. That one-on-one is very beneficial.”

-Conscious integration of father-inclusive language to normalize involvement

-Support for targeted outreach to fathers and one-on-one interactions

Complexity

Perceived difficulty of implementation, reflected by duration, scope, radicalness, disruptiveness, centrality, and intricacy and number of steps required to implement

Perceived barriers of the proposed intervention:

i. Virtual visits:

• Technological difficulties

• In-person demonstration preferred

ii. Home visits:

• Intrusiveness

• Tired/distracted parents

iii. General intervention:

• Scheduling conflicts

• Disagreement with information presented

i. “People have different levels of comfort with technology and have different devices.”

“I can tell you what wouldn’t be good virtually is lactation support… Somebody needs to show you. And I mean show your wife, and you be there.”

ii. “I think for some families they probably feel uncomfortable with other people in their home or telling them what to do or what’s best for their baby.”; “at that stage of three or four weeks, we're not able to process, record, and make the information useful because we are tired or distracted.”

iii. “Navigating any appointment ends up being navigating my wife's schedule, my schedule, the baby's, how the baby's doing. All of a sudden, anything becomes a little bit more complicated.”; “I may have different points of view of what they believe is correct.”

-Virtual visit tutorial available as needed; planned for in-person option but not available due to COVID19

-Reinforcement of visit materials through other materials (texts, emails, videos, printed materials)

-Meeting families’ preferences relating to comfort with visits/content

Design Quality &

Packaging

Perceived excellence in how the intervention is bundled, presented, and assembled

i. Preference for pre-and post-summary of visit topics

ii. Mixed opinions regarding visit timing and structure

iii. Diverse modalities of content delivery preferred

iv. List of intervention topics are appropriate, with a highlighted need for information on healthy eating, sleeping, and activity for babies and parents

i. “I’m definitely the kind of person who want to receive the material ahead of time, I could actually read it, digest it, and ask questions instead of trying to absorb it during the visit.”; “If there’s a summary sheet of the key takeaways or key things to look out for, it’s always helpful.”

ii. “One visit is probably not enough and two is—yeah I think that’s a perfect amount.”; “Maybe the first two visits are more closely scheduled, like we'll say 4 weeks, and then at 7 weeks, and then another one at 18 to 20 weeks.”

iii. “I like videos, absolutely, and a web page. Maybe even a quick text with someone on the other line.”; “I would say printed information is good, but also maybe a link to the same type of information online would be helpful as well.”

iv. “You’re hitting the nail on the head with every issue and period of the child’s growth that I think parents fear…Any way you can prepare parents with information before that will definitely put their mind at ease.”

-Preparation of “After Visit Summary” summarizing key content and dyad’s personal health goals – distributed after each Health Coaching Visit

-Additional material (printed, texts) provided after 3–4 month health coach visit

Adaptability

The degree to which an innovation can be adapted, tailored, refined, or reinvented to meet local needs

Tailoring the intervention to specific parental needs encourages participation and engagement maintenance

“In each of those virtual or in-person visits, there has to be one real aha takeaway that I feel like, ‘Wow. I wouldn’t have thought of that,’ or, ‘That really added something to my parenting toolbox,’ rather than feeling like I was just getting some generic information.”

Ensuring that health coach visits are customizable to dyad priorities, don’t seem too “scripted”, with resources relevant to dyad social needs