Druss 2010.

Methods	Allocation: randomised Blindness: single blinded Study duration: 6 months Location: single centre Design: parallel Setting: outpatients Country: USA Consent: written
Participants	Diagnosis: schizophrenia (28.8%), bipolar disorder (32.5%), major depression (26.3%), PTSD (11.3%) N = 80 History: not stated Sex: men 24, women 56 Age: mean 47.8, SD 10.1 years Exclusion criteria: not stated
Interventions	Group 1: peer‐support + standard care (n = 41). Content: 6 group sessions led by peer specialists, discussed the following topics: overview of self‐management; exercise and physical activity; pain and fatigue management; healthy eating on a limited budget; medication management; finding and working with a regular doctor. Delivered by: trained peer specialists. Frequency: peer support specialists. Treatment duration: 6 months. Group 2: standard care (n = 39). Content: receiving all medical, mental health and peer‐based services that they were otherwise receiving prior to entry into the study. Treatment duration: 6 months.
Outcomes	Service use: clinically important engagement Behaviour: patient activation Leaving the study early Peer outcomes: quality of life for participant and peer supporter Unable to use Global state: compliance with medication (see What's new)
Notes	Funding source: NIMH R34MH078583. We contacted the author to clarify whether peer support group received standard care; however, we received no reply. Usually outpatients in the usual care setting normally receive usual psychiatric care and thus are not deprived of any standard care or service in the community.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Using a computerized algorithm, patients were randomised to the intervention or standard care group by the project manager." Comment: adequate sequence generation.
Allocation concealment (selection bias)	Unclear risk	Comment: author did not describe allocation concealment. Insufficient information to permit judgement of low risk or high risk.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "The interviewers were blinded to subjects' randomisation status." Comment: blinding of personnel ensured. No blinding information for participants.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The interviewers were blinded to subjects' randomisation status." Comment: blinding of assessors ensured
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: 4 participants lost from intervention group and 11 participants lost from standard care group (data from Figure 1 of the publication), with reasons such as unable to locate, deceased and withdrawn. Analysis was included for attrition.
Selective reporting (reporting bias)	Unclear risk	Comment: study protocol not available. Insufficient information to make judgement.
Other bias	Low risk	None noted.