Carbone 2021.

Study characteristics
Methods	RCT
Participants	N = 225 (149F/76M) 'Major neurocognitive disorder' DSM‐V mild‐to‐moderate range (no information regarding medication) Mean MMSE 20.1 (SD 4.0) Age 83.6 (SD 8.1; range 50‐99) 16 residential homes and day‐centres
Interventions	Cognitive stimulation groups (N = 123) Usual treatment group sessions (N = 102)
Outcomes	Cognition: ADAS‐Cog; MMSE Language: Narrative Language Test Quality of life: QoL‐AD (self‐report) Mood: Cornell Scale for Depression in Dementia ADL: Disability Assessment for Dementia (DAD) Behaviour problems: NPI
Notes	45 minutes, twice a week, for 7 weeks; 3‐month follow‐up
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Covariate adaptive randomization was used at each participating centre".
Allocation concealment (selection bias)	Unclear risk	No information provided as to who carried out the randomisation or the process used for concealment of allocation
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"Conducted by trained psychologists who did not participate in the treatment program, and they had no information on participants’ group allocation".
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition at post‐treatment; reasons given for those dropping out; data sought for all participants irrespective of compliance
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias ‐ training and supervision	Low risk	One‐day training for at least one facilitator of each group, plus experience of dementia care and group facilitation skills
Other bias ‐ treatment manual	Low risk	Italian version of 'Making a difference' manual used (Spector 2006)