Svansdottir 2006

Methods	RCT (parallel). 6‐weeks intervention and 4‐weeks follow‐up. No information reported about start and end dates of data collection.
Participants	Country: Iceland. N = 38 (? female, ? male); residents in 2 nursing homes and 2 psychogeriatric wards. Age range: 71 to 87 (recruited sample, N = 48). Diagnosis of dementia: all diagnosed with Alzheimers disease (ICD‐10); Global Deterioration Scale (GDS) score of 5 to 7 (moderate to severe dementia).
Interventions	1) Group music therapy (three or four participants per session), mixed active (playing instruments) and receptive (listening), 3 times a week for 6 weeks (total of 18 sessions), 30 minutes per session. 2) Standard care as usual.
Outcomes	Behavioural and psychological symptoms of dementia (BPSD) assessed with the Behaviour Pathology in Alzheimer's disease Rating Scale (BEHAVE‐AD).
Notes	No clear baseline characteristics presented. Funded by the Research Fund for Alzheimer’s Disease and Related Disorders, Landspitali University Hospital.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information provided.
Allocation concealment (selection bias)	Unclear risk	Quote: "...The 46 remaining patients were then randomised to a music therapy group or a control group, with 23 individuals in each group".
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible to blind the convener and participants.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The outcome assessors were blinded. Quote: "Two nurses were trained in using the BEHAVE‐AD scale and they were blinded to the therapy used. The nurses were not part of the staff of the wards"..
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information provided.
Selective reporting (reporting bias)	Unclear risk	No data.
Other bias	Unclear risk	No clear baseline characteristics presented. First author (HBS) provided the music therapy. Quote: "Throughout the study the same qualified music therapist (H.B.S.) conducted the music therapy".