Mall 2006.

Methods	Method of randomisation: randomisation done using a predetermined list Blinding: both participants and assessors blinded to the intervention Intention‐to‐treat analysis: yes Loss of follow‐up: 4 children lost to follow‐up BoNT‐A group: Missing value (n = 1) Protocol violator (n = 1) Unblinded participant (n = 1) Placebo group: Missing value (n = 1) Unit of analysis: not described
Participants	Place: 9 centres in Germany and 1 centre in Austria Period of study: not described Number assigned: 61 Number assessed: 57 27 BoNT‐A group 30 placebo group Inclusion criteria: Children with CP and bilateral adductor spasticity Age from 18 months to 10 years Migration percentage < 50% Exclusion criteria: Hip dislocation Previous treatment with BoNT‐A within 9 months Previous surgery in injected muscles Age: BoNT‐A group (mean/SD/range): 6.08/3.0/1.92 to 10.83 years Placebo group (mean/SD/range): 5.75/2.17/2.33 to 10.0 years Gender: Both groups: 37 males; 24 females Motor distribution: BoNT‐A group: 22 leg‐dominant quadriplegia; 10 quadriplegia Placebo group: 17 leg‐dominant quadriplegia; 11 quadriplegia GMFCS: BoNT‐A group: 1 level I; 3 level II; 12 level III; 12 level IV; 4 level V Placebo group: 2 level I; 2 level II; 5 level III; 17 level IV; 2 level V
Interventions	BoNT‐A group: Single BoNT‐A injection (abobotulinumtoxinA) 30 IU/kg into adductors (2/3 total dose) and into the medial hamstrings (1/3 total dose) Placebo group: Injection of human albumin and lactose into adductors and the medial hamstrings
Outcomes	Length of follow‐up: Follow‐up of 3 months Assessments at baseline, weeks 4 and 12 Primary outcome: Knee‐knee distance Secondary outcomes: Hip abduction (range of movement) Modified Ashworth Scale Gross Motor Function Measure, total score and goal total score without aids and orthesis Goal Attainment Scale
Notes	Comments: none Source of funding: not reported Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: randomisation was done using a predetermined list
Allocation concealment (selection bias)	Low risk	Quote: "The master list was kept confidential by the drug supplier"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: both participants and personnel were blinded to the intervention
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: outcome assessors were blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: all predetermined outcomes were described in the results, but no means, SD, or P values were given for most of the non‐significant results. This was likely due to space restrictions in the journal.
Selective reporting (reporting bias)	Unclear risk	Comment: study protocol not available. It appears that the relevant outcomes were addressed.
Other bias	Low risk	Comment: no other sources of bias identified