Food is medicine: Testing 'medically tailored groceries' for pregnant women with food insecurity and high risk pregnancies in Australia

Each intervention participant will receive a 'prescription' for healthy food boxes delivered to their homes weekly by the study food supplier until they have given birth. The prescription will also contain simple recipes using foods availability in the health food boxes. Content of the healthy food boxes will be pre-determined by the study team and the food supplier, and will include fruit, vegetables, nuts and seeds, and low glycaemic index whole grain products that are appropriate for pregnant women and recommended by the Australian Dietary Guidelines. The amount provided will be tailored to household size, with the aim of supporting healthier food intake and it is not designed to replace all food intake. The prescription will allow the participants to take part in telephone appointments (up to 30 minutes) up to three times between randomisation and 28 weeks of gestation at approximately 2, 4 and 8 weeks post-randomisation with a trained accredited dietitian to support improvement in diet quality. The decision to take part in these dietitian consults will be at the participant's discretion. The dietitian will provide dietary advice, including a specific focus on how to cook the healthy foods provided to the participants. Participants will be advised to avoid foods that they are allergic or intolerant to and continue their usual medications, and any changes to medication requirements will be at the discretion of their treating clinician. To monitor adherence to the intervention, study staff who conduct the diet consultations will log the number of dietary counselling sessions with each participant. Participants will also be asked to complete a self-administered Process Evaluation questionnaire related to produce acceptability and uptake at gestation weeks 24-28 and 35-38. Each participant will receive a $100 voucher after the completion of data collection at baseline and mid-point, and $150 after data collection at the end-point (total $350). The vouchers can be used to purchase groceries at a local food retailer of their choice. There will be no specific recommendations about how the vouchers are to be spent. At the end of the study, informant interviews (up to 40 minutes in duration) will be conducted by phone (i.e., Microsoft teams or Zoom audio function) with one to two purposely selected representatives each from the food supplier (Managing Directors/Chief Executive Officers and other staff engaged in the intervention), clinical staff, and study staff as well as 12 purposely selected intervention participants (with a range of characteristics). A subset of 12 intervention participants will be invited to take part in a semi-structured interview (up to 30 minutes) to obtain an in-depth understanding of what worked or not, what and how the intervention could be improved, and what were the challenges and enablers of intervention uptake. For the food supplier interviews, study staff are in contact with them as part of running the study and will ask who may be willing to be interviewed. For clinicians, relationships exist (some are collaborators on this study) and these contact details will be used to ask who may be willing to be interviewed and provide the Information Statement to them. For study staff, willing interviewees will self-nominate and access the Information Statement and use our usual means of contacting each other. The interviews will seek to obtain an in-depth understanding of what worked (or not), for whom and how, challenges and facilitators, and any adaptations throughout the implementation process. For all key informant interviews (except among trial participants), verbal consent will be obtained at the start of the interviews as per the verbal consent script and consent will be audio-recorded.