Duggleby 2018.

Study characteristics
Methods	Design: Randomised parallel trial. No. of participating centres: Multicenter. Study dates: June 2015 to April 2017.
Participants	Inclusion criteria: Carers (18+ years) of community‐living care recipients with Alzheimer's disease and related dementia (ADRD) and two or more chronic conditions, and 65+ years. Carers were all English speaking and either a family or fried of the care recipient, with access to a computer and a valid email address Exclusion criteria: Non‐English speaking carers; care recipient under the age of 65 years, who did not have ADRD and chronic conditions, or who was not a community‐living care recipient. No. of participants randomised to interventions: ‐ My Tools 4 Care (MT4C) (n=101). ‐ Educational control group as usual care (n=98). Baseline characteristics: Caregivers: Mean age was 63.6 years (SD=11.6), 81% were female (161 of 199), most were spouse or partners (189 of 199, 95%), with a mean duration of care of 4.3 years (SD=4.2). Care recipients: Mean age was 80.3 years (SD=7.7), most were males (104 of 199, 52%).
Interventions	Experimental: MT4C is a Web‐based intervention intended to support carers . Control: Educational group Length of intervention: 3 months.
Outcomes	Primary outcomes: ‐ mental component summary score (MCS) from the SF‐12v2. Scores range from 0 to 100, with higher scores indicating a better health‐related quality of life. Secondary outcomes: ‐ physical component summary score (PCS) from the SF‐12v2. Scores range from 0 to 100, with higher scores indicating a better health‐related quality of life. ‐ General Self‐Efficacy Scale (GSES). Total scores range from 10 to 40, with higher scores indicating a greater level of self‐efficacy. ‐ Herth Hope Index (HHI). Total scores range from 12 to 48, with higher scores indicating a greater hope. ‐ Health and Social Services Utilization Inventory (HSSUI). Outcomes assessment: At 3 and 6 months after baseline.
Notes	Clinical trial registration code: NCT02428387. Funding: Canadian Institutes of Health Research (TTF 128261). Conflicts of interest: No competing interests declared. Fidelity / adherence: Authors report that 73% of caregivers used the intervention at least once over the 3‐month intervention period.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "A biostatistician...generated group allocations using stratified permuted block randomization".
Allocation concealment (selection bias)	Low risk	Quote: "Random number sequences were fed... into RedCap, a secure, password‐protected Web‐based randomization service... which allocated clients to the two groups according to a random sequence".
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "Given the nature of the study, the research team was unblinded to group allocation".
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: Data collection forms were emailed to participants following the first interview. However, outcomes were participant‐reported and intervention components and procedures were not comparable.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: intention‐to‐treat principles were used in all analyses. However, randomised groups presented differential attrition; at 3‐month 23 participants of 101 (23%) were lost to follow‐up in the intervention group whereas 9 participants of 98 (9%) were lost in the comparison group. Rates at 6‐month follow‐up were 27% (28/101) and 17% (17/98) respectively.
Selective reporting (reporting bias)	Low risk	Comment: study is registered (NCT02428387) and protocol published (Duggleby 2017). Reported outcomes agree with those described in registry and protocol.
Other bias	Low risk	Comment: none detected.