Table 1

Standard Protocol Items: Recommendations for Interventional Trials checklist for the evaluation of For Our Children’s Sake. Schedule for enrolment, informant, intervention and assessments.

		Time point
	Unit/informant	Pre-study	Baseline	Mid intervention	After intervention	3-month follow-up	Post follow-up
		-T0	T0	T1	T2	T3
Enrolment
Eligibility screen	Prison/parent	X
Allocation*	Prison	X
Informed consent	Parent/group leader/head of prison	X
Intervention
Intervention group
Control group							X
Outcome assessments
Primary outcome – CPRS	Parent		X		X	X
Secondary outcome – parent-child contact	Parent		X		X	X
Secondary outcome – MCAA	Parent		X		X	X
Secondary outcome – treatment interest	Parent		X		X	X
Mediator – AAPI-2	Parent		X	X	X	X
Mediator - PSE	Parent		X	X	X	X
Demographics	Parent/group leader/head of prison		X
Implementation process assessments
Adverse event reporting	Group leader					X
Treatment fidelity – group session audio recordings	Group leader
Intervention dose and reach	Parent/group leader/head of prison			X
Qualitative data – interviews – acceptability of intervention	Parent/group leader/head of prison						X

*Participant allocation based on the existing operation planning at each prison. Prisons where a parenting group is planned for the autumn 2019 will be allocated to the intervention condition, whereas prisons planning to conduct parental groups during 2020 are allocated to the control condition.
AAPI-2, Adult-Adolescent Parenting Inventory 2 ; CPRS, Child-Parent Relationship Scale; MCAA, Measures of Criminal Attitudes and Associates; PSE, parental self-efficacy, scale specifically developed for the project.