Ceccato 2009.

Methods	Allocation: randomised. Blindness: assessors were masked to treatment. Duration: 4 months. Design: parallel group.
Participants	Diagnosis: schizophrenia (ICD‐10). History: unknown. N = 67. Age: range 20 to 60 years. Sex: 41 M, 26 F. Setting: in‐ and outpatients (private clients).
Interventions	1. Group music therapy: Sound Training Attention and Memory (STAM). 1 weekly session (16 sessions in total). N = 37. 2. Standard care (medication and other therapeutic treatment indicated for schizophrenia). N = 30.
Outcomes	Cognitive functioning, attention: Paced Auditory Serial Addition Test (PASAT; Gronwall 1977). Cognitive functioning, vigilance and attention: Conners Continuous Performance Task 10 (CCPT; Rosvold 1956). Cognitive functioning, memory: Wechsler Memory Scale (WMS; Saggino 1983). Cognitive functioning, abstract thinking: Bergs' Card Sorting Test (BCST; Berg 1948).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised ‐ no further details.
Allocation concealment (selection bias)	Unclear risk	No details given.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Due to the nature of the intervention it was not possible to blind those who received music therapy or those who delivered it.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessors were masked to treatment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition.
Selective reporting (reporting bias)	Unclear risk	No study protocol available. All outcome measures described in the study were considered in the analysis.
Other bias	Unclear risk	Adequate music therapy method: unclear (highly structured approach, relational aspects unclear). Adequate music therapy training: yes (based on a general statement in the paper: 'qualified music therapists', and personal communication with the authors). No personal, financial, or any other interests producing bias could be found.