No.	Item	Question	Description
Domain 1: Research Team and Reflexivity Personal Characteristics
1.	Interviewer	Which author(s) conducted the interviews?	First author (ME) conducted interviews in Sydney.
2.	Credentials	What were the researchers’ credentials?	ME: MHS (Hons) ST: PhD SM: PhD LAB: MBBS, PhD CR: PhD LMW: PhD
3.	Occupation	What was their occupation at the time of the study?	ME: Doctoral candidate ST: Postdoctoral Fellow SM: Senior Research Fellow LAB: Professor CR: Director LMW: Manager
4.	Gender	Was the researcher male or female?	ME: Female ST: Female SM: Female LAB: Female CR: Male LMW: Male
5.	Experience and training	What experience or training did the researcher have?	ME: Formal training in qualitative methods; completed graduate-level coursework in qualitative research ST: Completed thesis studies on qualitative inquiry SM: Conducts original research in qualitative inquiry LAB: Clinical researcher with some experience in qualitative inquiry CR: Leads several qualitative research studies LMW: Leads several qualitative research studies.
Relationship with Participants
6.	Relationship established	Was a relationship established prior to study commencement?	Interviews were conducted via telephone and there were no pre-existing relationships between participants and the interviewer.
7.	Participant knowledge of the interviewer	What did the participants know about the researcher?	Participants were not given information about the interviewer beyond a brief introduction in an invitation email and in the participant information sheet provided with the email that described the interviewer’s role in this sub-study.
8.	Interviewer characteristics	What characteristics were reported about the interviewer?	None.
Domain 2: Study Design Theoretical Framework
9.	Methodological orientation	What methodological orientation was stated to underpin the study?	Qualitative description.
Participant Selection
10.	Sampling	How were participants selected?	Purposive sampling.
11.	Method of approach	How were participants approached?	By email and text messages.
12.	Sample size	How many participants were in the study?	34.
13.	Non-participation	How many people refused to participate or dropped out? Reasons?	Sixty-one women were approached via email and 25 participants passively rejected our invitation to participate without providing reasons other than general lack of interest in the study. 2 women who consented to participate did not answer the telephone on three separate occasions. 34 participants were interviewed.
Setting
14.	Setting of data collection	Where was the data collected?	Participants’ choice of location since they were contacted via mobile telephones.
15.	Presence of non-participants	Was anyone else present besides the participants and researchers?	None at the researcher’s end, unsure of who else was present at the participants’ end.
16.	Description of sample	What are the important characteristics of the sample?	Women who participated in the CHAT RCT trial and who agreed to participate in further sub-studies. Women caring for infants who were around 12 months of age with varying satisfaction levels at the six-month quantitative survey.
Data Collection
17.	Interview guide	Were questions, prompts, guides provided by the authors? Was it pilot tested?	Yes. The guide was improved/refined throughout pilot testing and during data collection process.
18.	Repeat interviews	Were repeat interviews carried out?	No.
19.	Audio/visual recording	Did the researcher use audio or visual recording to collect the data?	Interviews were audio-recorded.
20.	Field notes	Were field notes made during and/or after the interviews?	Yes. Field notes were made during and immediately following interviews.
21.	Duration	What was the duration of the interviews?	Approximately 20 min.
22.	Data saturation	Was data saturation discussed?	Yes.
23.	Transcripts returned	Were transcripts returned to participants for comment or correction?	No.
Domain 3: Analysis and Findings Data Analysis
24.	Number of data coders	How many coders coded the data?	Two researchers (ME and ST) coded one set of data independently. Codes and categories were discussed and refined within the research team. Following this, ME coded the remaining data
25.	Description of the coding tree	Did authors provide a description of the coding tree?	Yes.
26.	Derivation of themes	Were themes identified in advance or derived from the data?	Derived from the data.
27.	Software	What software, if applicable, was used to manage the data?	Microsoft Word.
28.	Participant checking	Did participants provide feedback on the findings?	No.
Reporting
29.	Quotations presented	Were participant quotations presented to illustrate the themes/findings? Was each quotation identified?	Yes, some quotations were included within the manuscript and all quotations in a separate table. Quotations were identified by category.
30.	Data and findings consistent	Was there consistency between the data presented and the findings?	Yes.
31.	Clarity of major themes	Were major themes clearly presented in the findings?	Yes.
32.	Clarity of minor themes	Is there a description of diverse cases or discussion of minor themes?	Both major and minor themes were discussed.