Gattino 2011.

Methods	Allocation: balanced randomisation using a table of random numbers Blindness: assessors blinded Duration: 7 months Design: parallel group
Participants	Diagnosis: autism spectrum disorder N = 24 Age: range 7 to 12 years (mean 9.75 years) Sex: 24 males, 0 females Setting: hospital
Interventions	1. Relational music therapy (improvisation not using a structured protocol; 3 assessment sessions, 16 intervention sessions, 1 final assessment session) in addition to standard treatment, 20 thirty‐minute sessions, scheduled weekly, n = 12 2. Standard treatment (clinical routine activities including medical examinations and consultations), n = 12
Outcomes	a) Verbal communication (Childhood Autism Rating Scale, Brazilian version, CARS‐BR) b) Nonverbal communication (CARS‐BR) c) Social communication (CARS‐BR)
Notes	Funding sources: Fund of Incentive to Research of Porto Alegre Clinical Hospital (project no. 08006), Brazilian Research Council (CNPq)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised (computer‐generated random sequence)
Allocation concealment (selection bias)	Low risk	Allocation was conducted by an external investigator
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	The fact that children with ASD participating in the study were not blinded was considered unlikely to introduce bias The possible risk of bias introduced by therapists administering the intervention was unknown
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessors were blinded to the randomisation result
Incomplete outcome data (attrition bias) All outcomes	Low risk	No drop‐outs No missing data reported
Selective reporting (reporting bias)	Low risk	All outcome measures of interest were considered in the analysis
Other bias	Low risk	Adequate music therapy method: yes Adequate music therapy training: yes