Harrison 1991.

Study characteristics
Methods	RCT. 2 arms.
Participants	Number of children: 50 control, 50 treatment Sex of children: 51 M, 49 F Age range of children: 6 ‐ 12 years Mean age range of children: 8.4 years Needle Procedure: venous blood sampling Diagnosis of child: none given Inclusion criteria: 6 ‐ 12 years Exclusion criteria: none given Setting: 4 hospital laboratories in Kuwait
Interventions	1. Preparation: Children were read a picture book just prior to the procedure that described the venous blood sampling procedure, why it is carried out, and what happens to the blood after it has been collected. The story stressed that pain is noticeable during the procedure but not unbearable, and that the procedure is less painful if you relax your arm and cooperate with the technician. Children were encouraged to ask questions. 2. No preparation control: No specific description was mentioned in the study. However, it was noted that initial observations revealed that laboratory technicians generally made no attempt to prepare children or to talk to them through the procedure. If children protested and struggled, their strategy was to physically restrain the child and complete the procedure. Often, parents were recruited to help.
Outcomes	Pain measures: Child self‐report: VAS (0 ‐ 5) Parent observer‐report of child pain: VAS (0 ‐ 5) Distress measures: Parent observer report of child’s fear: VAS (0 ‐ 5) Physiological measures: Radial pulse rate post‐procedure Adverse events: none mentioned
Notes	Study dates: study dates not reported Funding: Kuwait University Project MU072 Conflicts of interest: none declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomized ‐ no further details. Insufficient information to permit judgment of 'low' or 'high' risk
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 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	Unclear risk	Insufficient reporting of exclusions to permit judgment of 'low' or 'high' risk (e.g. some parent report missing)
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit judgment of 'low' or 'high' risk
Other bias	High risk	Had a potential source of bias related to the specific study design (e.g. potential impact of group setting)