Van Tilburg 2009.

Study characteristics
Methods	RCT. 2 arms. Assessed at pretreatment, post‐treatment, 6 months
Participants	End of treatment: n = 29; follow‐up: n = 24 Start of treatment: n = 34 Sex: 25 F, 9 M Mean age = 10.25 years (SD 2.6) Source = University of North Carolina and Duke University Medical Centres Diagnosis = functional abdominal pain Mean years of pain = unknown
Interventions	“Guided imagery treatment” “Standard medical care”
Outcomes	Primary pain outcome: Abdominal Pain Index Primary disability outcome: Functional Disability Inventory Primary depression outcome: none Primary anxiety outcome: none Abdominal Pain Index Functional Disability Inventory School attendance Pediatric Quality of Life Inventory Global rating of change in abdominal pain Treatment compliance Questionnaire of paediatric gastrointestinal symptoms Healthcare utilisation
Notes	COI: the authors indicated they had no financial relationships relevant to this article to disclose Funding: this work was supported by National Institutes of Health grants R24 DK067674 and RR00046
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Thirty‐four children were assigned randomly to receive 2 months of standard medical care with or without home‐based, guided imagery treatment.” Comment: probably done, method not described
Allocation concealment (selection bias)	Low risk	“Children picked a closed envelope that determined whether they would receive standard medical care with or without guided imagery treatment.” Comment: probably done
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No description found in text Comment: probably not done
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition was described, however significant differences between completers and non‐completers were not reported
Selective reporting (reporting bias)	Unclear risk	Data provided on request.