Bunbury to Bundaberg, Darwin to Dover: establishing a successful Regional Participation Program for the ENDIA type 1 diabetes cohort study

The Environmental Determinants of Islet Autoimmunity (ENDIA) study is a national longitudinal prospective cohort study which aims to identify the environmental factors that drive the development of type 1 diabetes (T1D) in at-risk individuals.1 Recruitment commenced in 2013 and is proceeding at eight hospitals across Adelaide, Sydney, Melbourne, Brisbane, Perth and Geelong, covering approximately 64% of the general population.2 In 2016, ENDIA launched the Regional Participation Program (RPP) to facilitate the participation of eligible families outside these cities.

The RPP incorporates ENDIA investigations that can be effectively performed in the family home or with assistance of local health care providers (eg, general practitioners, endocrinologists, midwives, obstetricians or pathology collection centres). For cost-effectiveness, the visits have been reduced from a 3-monthly1 to a 6-monthly basis, yet they will still provide valuable information, particularly as environmental exposures in regional areas may differ.

The RPP is coordinated by a dedicated research nurse at the Women’s and Children’s Hospital in Adelaide and by the ENDIA principal investigator, who will liaise with local health care professionals when required. The program has been approved by the Women’s and Children’s Health Network Human Research Ethics Committee (HREC/16/WCHN/66) and eligible patients are targeted through social media, advertising, advocacy groups and health professionals. Consent is taken via telephone using an RPP-specific participant information sheet and consent form that is signed, returned via mail and counter-signed indicating the date of the call.

Patients receive the collection materials, instructions, questionnaires and data collection sheets by mail, and they can also access the information on the ENDIA smartphone app. Samples are shipped to Adelaide via courier using the bio-freeze temperature controlled transport system, which patients place in the freezer at least 48 hours before shipping.

The bio-freeze maintains an internal temperature of below 0°C for 36 hours, over 10°C for 48 hours, and ambient for 96 hours. This allows adequate time for the samples to reach Adelaide, while maintaining sample integrity for downstream multi-omics applications.

Response to the RPP has exceeded expectations, with 28 participants giving their consent in 4 months and a recruitment rate of over 75% in regional areas, compared with 40–50% across metropolitan sites. Patients with T1D from regional areas are enthusiastic to participate, and the ENDIA-RPP model for engaging participants who live outside metropolitan recruitment sites could be adapted for other research studies in Australia.