Jackson 2013.

Study characteristics
Methods	Benefits of participation in diabetes group visits after trial completion RCT (NA clusters and NA providers), conducted in 1) Group medical clinics (GMC) were delivered at 2 Veterans Affairs Medical Centers (VAMCs), one in Durham (North Carolina) and another one in Richmond (Virginia). 2) Group education and structured group interactions were moderated by a registered nurse or certified diabetes educator. Individual medication adjustments were made by a pharmacist and general internist. Some of the nutrition discussions also included a dietitian. In United States of America. 2 arms: 1. Control (usual care) (control arm) and 2. Intervention (GMC: Group medical clinics) (intervention arm)
Participants	Control arm N: 106 Intervention arm N: 133, NA, NA Diabetes type: 3 Mean age: 62.02 ± 10.95 % Male: 95.81 Longest follow‐up: 30 months
Interventions	Control arm: (usual care) Intervention arm: (GMC: group medical clinics) 1) Case management 2) Team change 3) Facilitated relay of clinical information 4) Patient education 5) Promotion of self‐management 6) Patient reminders
Outcomes	Glycated haemoglobin Systolic blood pressure Diastolic blood pressure Low‐density lipoprotein Hypertension control Harms
Funding source	This research was funded by the Quality Enhancement Research Initiative (QUERI) of the Department of Veterans Affairs (VA) Health Services Research & Development (HSR&D) Service (RRP‐09‐ 407). The Group Visits Trial was funded by VA HSR&D (IIR‐03‐084). Dr Maciejewski is supported by a VA HSR&D Research Career Scientist Award (RCS‐10‐391).
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not reported. Patients were randomly assigned within each centre to either attend a GMC or receive usual care. We stratified randomisation by VAMC, baseline HbA1c level (≥ 9.0% vs < 9.0%), and baseline systolic blood pressure (≥ 150 mm Hg vs < 150 mm Hg). We randomly assigned patients to the GMC and usual care groups in a 5:4 ratio to account for clustering of patients in the group medical visits group; patients in the usual care group received their usual VAMC primary care. We used stratified, blocked randomisation with block sizes of 11.
Allocation concealment (selection bias)	Unclear risk	An unblinded person with no responsibility for outcome ascertainment revealed study group allocation to patients.
Patient's baseline characteristics (selection bias)	Low risk	From the original study (reference 2): Patients in the GMC and usual care groups were similar at baseline (Table 1).
Patient's baseline outcomes (selection bias)	Low risk	From the original study (reference 2): Patients in the GMC and usual care groups were similar at baseline (Table 1).
Incomplete outcome data (attrition bias)	High risk	From the original study (reference 2): At 12 months, they already lost 17/106 patients in the control group (16%) and 11/133 (8%) in the intervention group. Unbalanced numbers and reasons. Numbers of lost between 12 months follow‐up and 30 months are not given.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	All of our outcomes of interest were objectively measured (HbA1c, SBP and LDL).
Selective reporting (reporting bias)	High risk	Prospectively registered protocol. Primary outcomes match manuscript results (HbA1c, SBP). They have looked at DBP in the original study but not in this longest follow‐up. By opposition, they added LDL in this longest follow‐up. Secondary outcome of "Cost‐effectiveness" was reported; however, "Proportion of Patients With LDL < 100, Health Services Utilization, Quality of Life (as Measured by DQoL), Patient Empowerment (as Measured by DES)" were not reported.
Risk of contamination (other bias)	Unclear risk	Patient randomised within 2 Veterans Affairs Medical Centers (VAMCs) in Durham, North Carolina, and Richmond, Virginia. The usual primary care providers might have changed their approach with control patients after receiving information from their patients in the intervention group. Quotes: "We informed these patients’ primary care providers of medication changes solely by means of the electronic medical record". "A record of the plan was entered into the electronic medical record and forwarded electronically to the primary care provider". "Limitation: Measurements of effectiveness may have been limited by concomitant improvements in the usual care group that were due to co‐intervention". "The observed differences may have resulted from the extra attention provided to the GMC group rather than its content".
Other bias	Low risk	No evidence of other bias.