Studies were considered for this review if they described a cognitive stimulation intervention targeting cognitive and social functioning. These interventions may also have been described as RO groups, sessions or classes.
The definition of cognitive stimulation as proposed by Clare 2004 was adopted. This meant that some studies which described their intervention as 'cognitive stimulation' were excluded. Interventions needed to offer exposure to generalised cognitive activities rather than training in a specific modality.
Interventions were typically conducted in a group to enhance social functioning, or could involve family caregivers.
Studies were included if a comparison was made to 'no treatment', 'standard treatment' or placebo. Standard treatment was understood to be the treatment that was normally provided to patients with dementia in the study setting and could include provision of medication, clinic consultations, contact with a community mental health team, day care, or support from voluntary organisations. Placebo conditions could consist, for example, of an equivalent number of sessions in which general support, but no structured intervention, was offered.
The minimum duration of intervention for inclusion of a study was one month. There were no restrictions on the number of treatment sessions, although this was noted.