Mackillop family services’ family preservation and reunification response for vulnerable families—Protocol for an effectiveness-implementation study

International evidence supports the effect of intensive family preservation and reunification services in preventing children’s placement in out-of-home care (OOHC). Evidence within Australia is scarce. This protocol paper describes a hybrid effectiveness-implementation evaluation of the Victorian Family Preservation and Reunification (FPR) Response implemented by MacKillop Family Services. Participants include families engaged in the program and staff involved in program delivery. A pre-post study design will be used to assess the effectiveness of the FPR in improving family outcomes from intake to closure, including: (i) parenting knowledge, skills, and capability; (ii) family safety and home environment; (iii) child development, adolescent behaviour, education attendance and attachment; (iv) connection to services; and (v) prevention of children from entering or re-entering OOHC. Interviews and focus groups will be conducted with staff to evaluate the program’s fidelity, reach, feasibility, acceptability, and enablers and barriers to implementation. Quantitative data will be analysed using descriptive statistics and a series of paired-samples t-tests and F tests to examine changes in outcomes over time; thematic analysis will be used for qualitative data. If the FPR can yield significant improvements in families’ outcomes, this would provide strong support for its scale-up across Australia, to better support vulnerable families.