Table 1.

Comparison of the different components of the three studies of the GROKids project in detail

	Study 1	Study 2	Study 3
Time from the diagnosis of childhood cancer	0–2 years (Immediate and acute effects)	0–2 years (Immediate and acute effects)	3–10 years (Long-term effects)
Type of study	Quantitative	Qualitative	Quantitative
Method	Cohort study using self-administered questionnaires	Semi-structured interviews	Cross-sectional study using self-administered questionnaires
Identification of eligible families	• Prospective enrollment of new cases in clinics • Volunteer participation	Same as Study 1	• Through patient pediatric oncology patient list • Volunteer participation
Eligibility criteria	For grandchild with cancer • Diagnosis of any childhood cancer within the last three months, except “watch and wait” patients • Patient aged ≤ 18 years at diagnosis • Patient is a resident of Switzerland (or near the borders) at the start of the study • Patient is under active treatment • Treatment in Switzerland • At least one grandparent or step-grandparent is alive For grandparents • Fluent in German, French, or Italian	Same as Study 1	For grandchild cancer survivor • Diagnosis of any type of childhood cancer • Has been diagnosed 3 to 10 years ago and is off treatment, based on the date of diagnosis • Survivor aged ≤ 18 years at diagnosis • Survivor was a resident of Switzerland at the diagnosis • Survivor was under treatment (no watch-and-wait patients) • Treatment in Switzerland • At least one grandparent or step-grandparent is alive For grandparents • Fluent in German, French, or Italian
Time points	T1 – 3 months T2 – 6 months T3 – 1 year T4 – 2 years	Between T2-T4	T5-3 to 10 years from the diagnosis
Main Outcomes	• Acute and chronic disease • Pain • Quality-of-life • Depression and anxiety • Post-traumatic stress • Adaptations to stress • Partner and family relationships	• Experiences • Help and support • Health and well-being • Daily life and employment • Relationship • Advice to grandparents and positive outcomes	• Acute and chronic disease • Pain • Quality-of-life • Depression and anxiety • Post-traumatic stress • Adaptations to stress • Partner and family relationships
Analysis	Repeated measures using multilevel regression	Thematic content analysis	Univariable and multivariable regression