Kristjansdottir 2010.

Study characteristics
Methods	RCT. 3 arms.
Participants	Number of children: 39 control, 79 treatment Sex of children: 63 M, 55 F Age range of children: 13 ‐ 15 years Mean age of children: 14 ± 0.18 years Needle procedure: polio immunization Diagnosis of child: none (community sample) Inclusion criteria: Icelandic‐speaking adolescents for a ninth grade immunization Exclusion criteria: none reported Setting: school in Iceland
Interventions	1. Music distraction (with headphones):Adolescents listened to music using headphones. 2. Music distraction (without headphones): Adolescents listened to music from loudspeakers. 3. Standard care control: Nurses maintained their normal modes of caring, which were to comfort and guide the adolescents verbally.
Outcomes	Pain measure: Child self‐report: 0 ‐ 10 VAS Adverse events: none mentioned
Notes	Study dates: study dates not reported Funding: none stated Conflicts of interest: none declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "table of random numbers was used to randomize into groups" (p. 20 Par 11)
Allocation concealment (selection bias)	High risk	Use of an open random allocation schedule (e.g. random‐number table)
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	No missing data
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit judgment of 'low' or 'high' risk
Other bias	Unclear risk	Insufficient information to assess whether an important risk of bias exists