Using behaviour change theory to inform an innovative digital recruitment strategy in a mental health research setting.

Recruitment in mental health research is challenging, as some disorders such as depression or schizophrenia may involve vulnerable participants that lack motivation as part of their illness. A mental health diagnosis can be stigmatising, so privacy and access to hospital-based patient cohorts is carefully controlled. Our team describe a pragmatic portal recruitment process for facilitating timely recruitment into multiple research studies focusing on mental health. Three factors were analysed; evaluating the success and impact of this novel recruitment process; identification of patterns in recruitment to better target participants; and provision of metrics of the different media formats engaged. A web-based recruitment portal was developed by the research team in collaboration with the South Australian Health and Medical Research Institute (SAHMRI) Consumer & Carer Research Advisory Group. A comprehensive marketing campaign was then undertaken to direct participants towards the portal. Recruitment insights from the dates and times of registration across a two-year period is provided. In total, 933 potential participants registered with the recruitment portal across a two-year period at a cost of approximately $10,000. The advertisement campaign linked to the portal page enabled 506 participants to register in just one week. The area of research was self-selected by the potential participants, then eligibility was followed up with telephone and face to face interviews. Of the total 933 people who registered 706 (76%) expressed an interest in the target clinical depression study, 119 (13%) opted to be clinical controls, and the remainder chose one of the alternative studies. 240 (26%) of those who registered were excluded through telephone interviews because they fell outside of the strict eligibility criterion. We learnt that 77% (n = 723/933) of participants were recruited within seven days of promotional events, providing an interesting pattern of recruitment that may assist future recruitment design.