Table 3

Overview of measures at the respective assessments

Variable/phenomena	Measure	Eligibility interview	Baseline	Postassessment	Weekly process evaluation	Six-month follow-up	Mode of administration
Child age, gender, diagnosis, date of first diagnosis, date of end of treatment (where available) and type of treatment	The Swedish Childhood Cancer Registry						Swedish Childhood Cancer Registry (recruitment strategy A)/telephone (recruitment strategy B)
Inclusion and exclusion criteria; parent background data; date of end of treatment of child’s treatment and whether child has had any recurrence	Structured questions	✓					Telephone
Psychiatric (mood and anxiety) disorders, drug and alcohol misuse and suicidality	MINI	✓		✓		✓	Telephone
Presenting psychological difficulties and related needs; expectations concerning the ENGAGE intervention; main distressing concerns regarding healthcare utilisation and productivity losses related to their child’s cancer	Semistructured questions		✓				Telephone
PTSS	PCL-5		✓	✓	✓	✓	Portal/telephone Only Portal during intervention
PTSS	PCL-C		✓	✓	✓	✓	Portal/telephone Only Portal during intervention
Depression	PHQ-9		✓	✓	✓	✓	Portal/telephone Only Portal during intervention
Anxiety	GAD-7		✓	✓		✓	Portal/telephone
Fear of recurrence	Structured question		✓	✓		✓	Portal/telephone
Fear of serious health condition	Structured question		✓	✓		✓	Portal/telephone
Psychological inflexibility and experiential avoidance	AAQ-6		✓	✓	✓	✓	Portal/telephone Only Portal during intervention
Depressed inactivity	BADS		✓	✓	✓	✓	Portal/telephone Only Portal during intervention
Fatigue	FSS		✓	✓		✓	Portal/telephone
Quality of life	EQ-5D		✓	✓		✓	Portal/telephone
Self-compassion	SCS-SF		✓	✓		✓	Portal/telephone
Health economics	TiC-P		✓	✓			Portal/telephone
Acceptability of the intervention; e-therapist; and study procedures; views concerning the impact of the ENGAGE intervention. Non-attendees and poor attendees are asked about reasons for disengaging, barriers to treatment and suggestions for future intervention development and study procedures.	Semistructured questions			✓			Telephone

AAQ-6, Acceptance and Action Questionnaire; BADS, Behavioural Activation for Depression Scale; EQ-5D, EuroQol 5-dimension questionnaire; FSS, Fatigue Severity Scale; GAD-7, Generalized Anxiety Disorder 7-item scale; MINI, Mini-International Neuropsychiatric Interview; PCL-5, Post-traumatic Stress Disorder Checklist for DSM-5; PCL-C, Post-traumatic Stress Disorder Checklist-Civilian version; PHQ-9, Patient Health Questionnaire; PTSS, symptoms of post-traumatic stress; SCS-SF, Self-Compassion Scale-Short Form; TiC-P, Trimbos and Institute of Medical Technology Assessment Cost Questionnaire for Psychiatry.