Table 2 Qualitative study design

1. Interviewer/facilitator

All interviews will be conducted by the same member of the study team.

2. Credentials

The interviewer will be a masters-level trained research assistant.

3. Occupation

The interviewer will be employed full-time as a research assistant.

4. Gender

The interviewer will be female.

5. Experience and training

The interviewer will have experience participating in qualitative research studies and will be supervised by the study PI, who has extensive training and experience conducting qualitative research.

6. Relationship established

Potential interviewees will be contacted with a standardized recruitment email to introduce the study and the interviewer and to request their participation.

7. Participant knowledge of the interviewer

The recruitment email will explain the study goals and why the interviewer is interested in conducting this research. This information will be reviewed at the start of each interview.

8. Interviewer characteristics

The recruitment email will provide information about the research team, including the interviewer. This information will be reviewed at the start of each interview.

9. Methodological orientation and theory

The qualitative portion of the study will use a content analysis approach.

10. Sampling

Potential interviewees will be selected based on their legally established responsibilities relative to the state law(s) of interest.

11. Method of approach

Potential interviewees will be approached with a standardized recruitment email.

12. Sample size

We anticipate conducting 3–5 interviews in each of the 15 intervention states.

13. Non-participation

We will document any reasons provided by those who decline to participate as well as any individuals who do not respond to our recruitment email.

14. Setting of data collection

Data will be collected via interviews conducted by telephone or videoconference.

15. Presence of non-participants

We anticipate that the interviewer and interviewee will be the only individuals present.

16. Description of sample

The sample will include key implementation leaders for the law(s) of interest in each of 15 intervention states.

17. Interview guide

The interview guide will be developed by the study team and shared with an advisory board for feedback. It will be pilot tested and refined before data collection begins.

18. Repeat interviews

We will conduct repeat member-checking interviews with a random sample of 20–30 interviewees.

19. Audio/visual recording

Once permission is granted, videoconference interviews will be recorded.

20. Field notes

The interviewer will draft summary notes immediately after concluding each interview.

21. Duration

We anticipate that interviews will last no more than 60 min.

22. Data saturation

The study team will convene on a regular basis to review interview data and determine when data saturation is reached.

23. Transcripts returned

We do not plan on returning transcripts to interviewees. Based on the straightforward nature of our questions and prior research with similar types of interviewees, we do not anticipate that this will be necessary.

24. Number of data coders

We plan to have two coders pilot a sub-sample of transcripts. Once discrepancies are resolved and the codebook is finalized, the full set of transcripts will be coded by one individual.

25. Description of the coding tree

We plan to develop a coding tree (i.e., codebook) based on a review of the literature, a priori knowledge within the study team, and summary notes from interviews. We will also share a draft codebook with our advisory board for feedback.

26. Derivation of themes

Themes will be derived once data have been coded. Preliminary themes may be identified based on discussions with the interviewer and review of field notes.

27. Software

We plan to use NVivo qualitative research software.

28. Participant checking

A bulleted list of key findings will be shared with participants once data have been coded and analyzed.

29. Quotations presented

Quotations from interviews will be used to present findings, and they will be accompanied by an interviewee identification number.

30. Data and findings consistent

Our planned use of quotations will allow for assessment of consistency between our data and findings. We will also create supplemental tables with additional quotations to share as much information as possible when presenting our findings.

31. Clarity of major themes

We plan to use sub-headings listing our major themes to promote clarity when writing up our findings.

32. Clarify of minor themes

We plan to provide quotations from interviewees who raised minor themes or shared information contrary to findings of our major themes.