Kay 2004.

Methods	Method of randomisation: children randomly assigned with use of a random number generator Blinding: all investigators except the study co‐ordinator and the physician performing the BoNT‐A injections were blinded to children's group assignments Intention‐to‐treat analysis: no Loss of follow‐up: no losses to follow‐up Unit of analysis: lower limb
Participants	Place: 1 centre in the USA Period of study: not described Number assigned: 23 Number assessed: 23 11 BoNT‐A + casts group 12 casts group Inclusion criteria: Diagnosis of CP with associated spastic diplegia, hemiplegia, or quadriplegia Aged 4 years or older Plantarflexion contracture (range of ankle passive dorsiflexion of < 0° with the knee extended) Ability to walk with or without assistive devices No history of orthopaedic surgery or selective dorsal rhizotomy in the preceding 12 months Exclusion criteria: Mixed CP Age: BoNT‐A + casts group (mean/SD): 6.9/2.8 years Casts group (mean/SD): 7.3/3.3 years Gender: BoNT‐A + casts group: 6 males; 5 females Casts group: 6 males; 6 females Motor distribution: BoNT‐A + casts group: 5 hemiplegia; 6 diplegia; 0 quadriplegia Casts group: 4 hemiplegia; 7 diplegia; 1 quadriplegia GMFCS: Not clearly described BoNT‐A + casts group: 2 using walking aids (likely GMFCS III) and 9 independent walkers (likely GMFCS I or II) Casts group: 3 using walking aids (likely GMFCS III) and 9 independent walkers (likely GMFCS I or II)
Interventions	BoNT‐A + casts group: Single BoNT‐A injection into the gastrocnemius muscles (onabotulinumtoxinA) 8 U/kg, maximum dose 400 U per child BoNT‐A was also injected into soleus (1 child) and medial hamstrings (2 children) Serial casting for equinus contracture started 1 to 3 weeks after the injection, applied every 2 weeks until > 5° of dorsiflexion was reached with the knee extended After casting, children received nighttime splints Usual physical therapy was maintained Casts group: Serial casting for equinus contracture started after the initial assessment, applied every 2 weeks until > 5° of dorsiflexion was reached with the knee extended After casting, children received nighttime splints Usual physical therapy was maintained
Outcomes	Length of follow‐up: Follow‐up of 12 months Assessments at baseline, 3, 6, 9, and 12 months post‐treatment Primary outcomes: Passive ankle dorsiflexion Spasticity (Modified Ashworth Scale) Gross Motor Function Measure Computerised gait analysis
Notes	Comments: We included this study in the 'BoNT‐A versus serial casting' comparison in the review for simplicity, since it ultimately evaluates the effect of adding BoNT‐A to a serial casting protocol in comparison to serial casting alone. Source of funding: in support of their research or preparation of this manuscript, 1 or more of the study authors received grants or outside funding from Allergan Conflicts of interest: despite the funding mentioned above, the study authors declared no conflicts of interest
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: children were randomly assigned with the use of a random number generator
Allocation concealment (selection bias)	Unclear risk	Comment: allocation was not clearly described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: no blinding of participants
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: the study authors state that all investigators except the study co‐ordinator and the physician performing the BoNT‐A injections were blinded to children's group assignments. However, we noticed that the study co‐ordinator was responsible for many of the assessments.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no missing outcome data
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