Rapoff 2014.

Methods	RCT. 2 arms. Assessed at pretreatment and post‐treatment
Participants	End of treatment: N = 22 Start of treatment: N = 35 Sex: 25 F, 10 M Mean age: 10.2 (SD 1.75) Source: paediatric headache clinics at 1 university and 2 children's hospitals Diagnosis: headache Mean years of pain: unknown
Interventions	"Headstrong programme" "Education"
Outcomes	Primary pain outcome: none Primary disability outcome: Pediatric Migraine Disability Assessment Primary depression outcome: none Primary anxiety outcome: none Primary satisfaction outcome: none Measures reported: headache diaries including frequency, intensity/severity, and duration Pediatric Migraine Disability Assessment Pediatric Quality of Life Inventory
Notes	Funding source: National Institutes of Health (National Institute of Neurological Disorders and Stroke), R01‐NS046641 (PI: Michael Rapoff) Declarations of interest: authors have no conflicts of interest
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Participants were stratified by age (7–9 and 10–12) and randomly assigned following baseline to one of the two groups (education control or Headstrong)." Comment: probably done; description of randomisation not provided
Allocation concealment (selection bias)	Unclear risk	No description found in text Comment: probably not done
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No description found in text Comment: probably not done
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Measures completed at home and mailed back
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Attrition completely reported; significant differences between completers and non‐completers were not reported
Selective reporting (reporting bias)	Low risk	Data were fully reported