Clare 2019.

Study characteristics
Methods	Parallel‐group, multicentre, single‐blind randomised controlled trial comparing cognitive rehabilitation added to usual treatment with usual treatment alone for people with dementia, mild‐to‐moderate cognitive impairment (MMSE score ≥ 18), living at home, and with a care partner willing to contribute
Participants	475 people (248 men) with an ICD‐10 diagnosis of Alzheimer's disease, vascular or mixed dementia
Interventions	Cognitive rehabilitation: participants involved worked collaboratively on up to 3 rehabilitation goals chosen by the participant, using a problem‐solving approach, supplemented if needed by emotion regulation and behavioural activation strategies to address motivational and emotional difficulties, reviewing and optimising participants' existing use of strategies to manage cognitive difficulties, providing practice in maintaining attention and concentration, signposting to relevant services, and offering support for care partners (10 weekly sessions over 3 months and 4 maintenance sessions over 6 months) Treatment as usual: typically consisted of medication, monitoring, and general psychosocial support
Outcomes	Outcomes were reported at 3 and 9 months. The primary outcome was self‐rated goal attainment (at 3 months). Secondary outcomes for participants were: participant‐rated goal attainment (at 9 months), care partner‐rated goal attainment and self‐rated satisfaction with their goal attainment, self‐rated self‐efficacy (Generalised Self‐Efficacy Scale), mood (Hospital Anxiety and Depression Scale), dementia‐specific health‐related quality of life (DEMQOL), memory (story recall from the Rivermead Behavioural Memory Test‐II), attention (elevator counting and elevator counting with distraction subtests from the Test of Everyday Attention), and executive function (verbal letter fluency from the Delis‐Kaplan Executive Function System) Secondary outcomes for carers: self‐reported stress (Relatives' Stress Scale), quality of life (WHOQOL‐BREF), and health‐related quality of life (EQ‐5D).
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was done by remote location via an online webpage.
Allocation concealment (selection bias)	Low risk	Allocation concealment is intrinsic to a remote computerised randomisation system used in the study.
Blinding of participants and personnel (performance bias) All outcomes	High risk	All outcomes were administered by blinded researchers, but "In the majority of cases, researchers were able to correctly guess the participant’s allocation." "In 48.4% of cases, researchers acknowledged that their guesses were influenced by the presence or absence of change in the participant’s goal performance rating."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The trial researchers were blind to the participants’ group allocation. Owing to the nature of the intervention, it was not possible to blind participants and carers to group allocation. "Participants explicitly disclosed their group allocation to the researchers in 14.8% of cases".
Incomplete outcome data (attrition bias) All outcomes	Low risk	The missing outcome measures at baseline were imputed using the centre‐level factors and the participant’s sex, age, and baseline MMSE scores. The missing outcome measure scores at the 3‐month and 9‐month assessments were estimated based on centre‐level factors, baseline characteristics, and scores for the same outcome at the earlier time point(s).
Selective reporting (reporting bias)	Low risk	There was no evidence for selected measures being reported in the report.
Other bias	Low risk	There was no evidence for other significant sources of bias.
Training of those delivering the intervention	Low risk	All therapists were trained by an experienced occupational therapist. "The intervention was delivered by trained therapists (nine occupational therapists and one nurse) who received regular individual and group supervision to ensure fidelity to the protocol."
Intervention manual	Low risk	"To support the implementation, we will develop materials, resources and training programmes." A manual has been subsequently released.