Gold 2015.

Study characteristics
Methods	Feasibility and impact of implementing a private care system's diabetes quality improvement intervention in the safety net: a cluster‐randomized trial Clustered RCT (11 clusters and NR providers), conducted in 1) The 11 study community health centres (CHCs) are ambulatory primary care clinics managed by 3 Federally Qualified Health Center (FQHC) systems in the Portland, Oregon metropolitan area. All are members of Oregon Community Health Information Network (OCHIN, Inc.), a non‐profit organisation that provides health information technology to safety net clinics. 2) The intervention is a system‐ and clinic‐level QI intervention (iterative, stakeholder‐driven process). In United States of America. 2 arms: 1. Control (late clinics) (control arm) and 2. Intervention (early clinics: cardioprotective prescribing) (intervention arm)
Participants	Control arm N: 1179 Intervention arm N: 1446, NA, NA Diabetes type: 4 Mean age: NR ± 8.6 % Male: 40.32 Longest follow‐up: 12 months
Interventions	Control arm: (late clinics) Intervention arm: (early clinics: cardioprotective prescribing) 1) Audit and feedback 2) Clinician education 3) Clinician reminder 4) Patient education
Outcomes	Lipid‐lowering drugs Antihypertensive drug
Funding source	National Heart, Lung & Blood Institute, 1R18HL095481‐01A1
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported. Cluster‐randomisation was used because this is a clinic‐level intervention with clinic‐level outcomes. Randomisation was matched on size of the clinics’ patient population and the FQHC system operating the clinic.
Allocation concealment (selection bias)	Low risk	Clustered RCT.
Provider's baseline characteristics (selection bias)	Unclear risk	11 community health centres (CHCs) were randomised with 6 “early” CHCs implementing the intervention 1 year before 5 “late” CHCs. No data on CHCs' characteristics are reported in each arm at baseline.
Patient's baseline characteristics (selection bias)	Low risk	Percentage of CVD, age and gender are similar between control and intervention arms at baseline (June 2011, Table 2). Nothing about possible differences in text are provided.
Patient's baseline outcomes (selection bias)	Low risk	Percentage of patients with active prescription for ACE/ARB, statin at baseline (June 2011): intervention: 49.9%, control: 45.4%. Percentage of patients with active prescription for statin at baseline (June 2011): intervention: 51.6%, control: 47.8%. Similar % between control and intervention at baseline, nothing reported in text about possible differences.
Incomplete outcome data (attrition bias)	High risk	They have more people at the end of the intervention than at baseline (control: 1179 to 1436 (+21.8%), intervention: 1446 to 1599 (+10.6%). Increases not balanced.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Objective outcomes. Data for cardioprotective prescription was extracted from electronic health record (EHR).
Selective reporting (reporting bias)	High risk	Retrospectively registered protocol (first posted 24 November 2014 and the study began in May 2010). Protocol does not mention percent appropriately prescribed statins only.
Risk of contamination (other bias)	High risk	Clustered RCT. However, some patients and providers likely “crossed over” from early to late clinics during the study year, even though the intervention components were only activated for staff at specified clinics per our randomisation strategy; this is because a small percentage of CHC staff served patients at both early and late clinics, and the point‐of‐care alerts were seen by early CHC providers regardless of where they provided care.
Other bias	Low risk	No evidence of other bias.