Qu 2012.

Methods	Allocation: randomised. Blindness: unknown. Duration: 16 weeks. Design: parallel group.
Participants	Diagnosis: schizophrenia (CCMD‐3). History: range from 2.2 to 5 years. N = 58. Age: mean 31.6 years. Sex: 43 M, 15 F Setting: inpatients.
Interventions	1. Group music appreciation and song singing in addition to standard care: 90 minutes per session, 2 sessions per day for 16 weeks. The intervention is combined with token rewards. N = 29. 2. Standard care includes antipsychotic medication, life skill training, health education, and recreative activities. N = 29.
Outcomes	Mental state, negative symptoms: Scale for the Assessment of Negative Symptoms (SANS; Andreasen 1982). Unable to use ‐ insufficient data: Social functioning: Inpatient Psychiatric Rehabilitation Outcome Scale (IPROS).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details given.
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	Unclear risk	No details given.
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 analyses
Other bias	Unclear risk	Adequate music therapy method: unclear Adequate music therapy training: limited. Music therapy was conducted by a nurse with good singing skills. No personal, financial, or any other interests producing bias could be found.