Solberg 2015.

Methods	Non‐randomised controlled trial (2 arms from stepped wedge evaluation) USA
Participants	2348 patients with depression; mean age 44 years; 73% female 75 primary care clinics
Interventions	The DIAMOND model (adopted from the IMPACT (Improving Mood: Promoting Access to Collaborative Treatment) study) included 7 components: 1. Use of the 9‐item Patient Health Questionnaire (PHQ‐9) depression scale for monitoring depression severity 2. Systematic participant follow‐up tracking and monitoring 3. Treatment intensification for participants not improving 4. Relapse prevention planning for participants achieving remission 5. On‐site care manager for educating, monitoring and co‐ordinating care 6. Scheduled weekly caseload review with a consulting psychiatrist 7. Monthly descriptive data submissions Comparison: usual care
Outcomes	Primary outcomes Depression severity (PHQ‐9) Secondary outcomes Care received, work productivity (Work Productivity and Activity Impairment, WPAI), health status, satisfaction
Notes	Study duration 5 years
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No randomisation (NRCT design)
Allocation concealment (selection bias)	High risk	No randomisation (NRCT design)
Baseline characteristics	Low risk	Reported and similar
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	All sites received intervention at different time points but all sites had intervention training.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	67% follow‐up
Selective reporting (reporting bias)	Low risk	Outcomes in methods reported
Protection against contamination	High risk	Risk of contamination due to non‐randomised design. Control data from 6 months before but training ongoing during this time
Other bias	Low risk