Thomas 2003.

Methods	Allocation: randomised order of treatment Blindness: no blinding Duration: 12 weeks Design: cross‐over (within each session)
Participants	Diagnosis: autism, N = 6 Age: range 2 to 3 years Sex: 5 males, 1 female Setting: not known
Interventions	1. Music therapy (using songs, instruments, vocal sounds and movement to interact with the child and musically or verbally respond to the child's verbal or non‐verbal behaviour), twelve 15‐minute session parts, immediately following or preceding playtime session parts, n = 6 2. Playtime (attempts to interact with the child using toys and verbally responding to the child's non‐verbal or verbal behaviour), twelve 15‐minute session parts, immediately following or preceding music therapy session parts, n = 6
Outcomes	Behaviour observation of videotaped sessions a) On‐task behaviour (percentage of session time) b) Requesting behaviour (percentage of session time)
Notes	Funding source: Mid‐Atlantic Region of the American Music Therapy Association.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised, no further details given
Allocation concealment (selection bias)	Unclear risk	No details given
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	Unclear risk	No details given if the assessor was 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