Allen 2011.

Study characteristics
Methods	COACH Trial: a randomized controlled trial of nurse practitioner/community health worker cardiovascular disease risk reduction in urban community health centres Patient RCT (NA clusters and NA providers), recruited from 2 community health centres (part of Baltimore Medical Systems Incorporated ‐ BMS, a federally qualified community health centre). In USA. 2 arms: (control arm) (intervention arm)
Participants	Control arm N: 264 Intervention arm N: 261, NA, NA Diabetes type: 2 Mean age: NR ± NR % Male: NR Longest follow‐up: 12 months
Interventions	Control arm: (enhanced usual care (EUC)) 1) Clinician education 2) Clinician reminder 3) Patient education 4) Patient reminder Intervention arm: (Nurse Practitioner/Community Health Worker (NP/CHW)) 1) Case management 2) Team change 3) Patient education 4) Promotion of self‐management
Outcomes	1) Glycated haemoglobin 2) Systolic blood pressure 3) Diastolic blood pressure 4) Low‐density lipoprotein
Funding source	This study was supported by the National Heart Lung and Blood Institute, National Institutes of Health grant # R01HL082638
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described: "…participants were randomly assigned."
Allocation concealment (selection bias)	Unclear risk	Not described: "…participants were randomly assigned."
Patient's baseline characteristics (selection bias)	Low risk	In table and text. Quote: "There were no significant differences in sociodemographic and baseline measures between the two groups except for higher total cholesterol and HbA1c levels in the NP/CHW intervention group compared to the EUC."
Patient's baseline outcomes (selection bias)	High risk	HbA1c (P = 0.006).
Incomplete outcome data (attrition bias)	Low risk	Intention‐to‐treat analysis with imputations, non‐significant differences in attrition rates, number and reasons for loss to follow‐up provided. Baseline based on those randomised.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Primary: lipids, blood pressure, HbA1c. LDL measured using Friedewald equation. HbA1c measured using liquid chromatography. Blood pressure using Omron digital blood pressure monitor. Blinding not described.
Selective reporting (reporting bias)	High risk	Some primary outcomes listed in protocol were not reported in the manuscript: physical activity, smoking cessation, antiplatelet use, beta blockers use, ACE inhibitors use.
Risk of contamination (other bias)	High risk	Quote: "…physicians had patients in both the intervention and the EUC groups. This may have resulted in a change in the level of care provided to their patients in the EUC groups…"
Other bias	Low risk	Information not available.