Nilsson 2015.

Study characteristics
Methods	RCT (randomized cross‐over trial). 2 arms.
Participants	Number of children: 20 control first, 17 treatment first Sex of children: 0 M, 37 F Age range of children: 11 ‐ 12 years Mean age range of children: not reported Needle procedure: vaccination Diagnosis of child: none reported Inclusion criteria: 11 ‐ 12 years, receiving 3 HPV vaccinations Exclusion criteria: none given Setting: three schools in western Sweden
Interventions	1. Relaxation and guided imagery: Nurses provided relaxation and guided imagery during the procedure. Children were encouraged to progressively relax their muscles and think about something positive. The nurse encouraged them to engage in the fantasy by asking detailed questions about it. 2. Standard care: Standard care was performed according to regulations. The nurses were instructed to talk as they normally do during vaccinations without any systematic relaxation or other non‐pharmacological or pharmacological intervention.
Outcomes	Pain measure: Child self‐report: Color Analogue Scale (CAS) Distress measure: Child self‐report: verbal rating scale for stress (0 ‐ 10) Physiological measure: Salivary cortisol (nmol/L) Adverse events: none mentioned
Notes	Outcomes included from time 1 only (before the cross‐over to other condition) Study dates: September 2012 to September 2013. Funding: grants from the Ebba Danelius Foundation, Swedish Association of Paediatric Nurses, the Gertrud Östlinder Foundation and the Jerring Foundation. Conflicts of interest: none declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "using a computer program (randomizer.org)" (p. 726)
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgment of 'low' or 'high' risk
Blinding of participants and personnel (performance bias) All outcomes	High risk	Study participants and personnel were not blinded
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding of outcome assessment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Some missing data but likely not related to outcomes of interest
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit judgment of 'low' or 'high' risk
Other bias	Low risk	Appears to be free of other bias that would affect outcomes