Riddell 2016.

Study characteristics
Methods	Cardiovascular risk outcome and program evaluation of a cluster randomised controlled trial of a community‐based, lay peer led program for people with diabetes Clustered RCT (24 clusters and NR providers), conducted in 1) 24 geographic communities within the state of Victoria in Australia (Local Government Authorities (LGAs)) were selected, from which study participants were recruited. Monthly community‐based group meetings. 2) Intervention programme led by trained peer supporters. In Australia. 2 arms: 1. Control (routine care) (control arm) and 2. Intervention (peer support intervention) (intervention arm)
Participants	Control arm N: 120 Intervention arm N: 120, NA, NA Diabetes type: 2 Mean age: 60.9 ± NR % Male: 50.8 Longest follow‐up: 12 months
Interventions	Control arm: (routine care) 1) Case management Intervention arm: (peer support intervention) 1) Case management 2) Patient education 3) Promotion of self‐management 4) Patient reminders
Outcomes	Glycated haemoglobin Systolic blood pressure Diastolic blood pressure Low‐density lipoprotein
Funding source	Funding and program support for this study was obtained from Peers for Progress, a global initiative funded by the American Academy of Family Physicians Foundation and the Eli Lily Foundation. Diabetes Australia‐Victoria provided funding and in kind program support.
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Reference 28: Allocation to intervention or usual care was governed by a random number generation process using Stata statistical software, Release 11.
Allocation concealment (selection bias)	Low risk	Clustered RCT.
Provider's baseline characteristics (selection bias)	Unclear risk	24 study locations (“clusters”). No data on each location and peer supporters involved. Locations are suitable if the population was more than 10,000 and the density of NDSS registrants was more than 2.5%.
Patient's baseline characteristics (selection bias)	Low risk	Table 1 and in text: The median duration of diabetes was 2 years longer in intervention participants compared with usual care participants (9 years vs 7 years, P = 0.01).
Patient's baseline outcomes (selection bias)	Low risk	Tables 2 and 3. There was higher baseline risk in the intervention arm, but no P values.
Incomplete outcome data (attrition bias)	High risk	They lost a total of 33 patients out of 240 (13,8%), 11 (9,2%) in the control group and 22 (18.3%) in intervention group. Unbalanced numbers.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Our outcomes of interest were objectively measured (HbA1c, SBP, DBP and LDL).
Selective reporting (reporting bias)	High risk	Prospectively registered protocol. Primary outcome in the protocol is HbA1c and the predicted 5 year cardiovascular disease risk using the United Kingdom Prospective Diabetes Study (UKPDS), while in the paper it is just CVD risk score. No data reported at 18 months as stated in the protocol.
Risk of contamination (other bias)	Low risk	Clustered RCT.
Other bias	Low risk	None.