Benjamin 1999.

Methods	CBA Characteristics of studies using second site as control: NOT DONE Follow up: ‐ providers: NOT CLEAR ‐ patients: NOT DONE Blinded assessment: DONE for HbA1c, NOT CLEAR for process measures Baseline: DONE for HbA1c, NOT DONE for eye exam, urine test for albumin/protein Reliable outcomes: DONE for HbA1c, NOT CLEAR for process outcomes Protection against contamination: DONE unit of analysis error
Participants	Outpatient clinics of Baystate Medical Center, Springfield (US). This Medical Center has a "firm" system that is an academic group practice that includes attending physicians, residents, nurses, a nutritionist and patients. The firm system creates two group practices that are essentially parallel groups of providers and patients. Patients are predominantly minority patients of Hispanic and African‐American descent. (Type 2 diabetes) providers ‐ ? (physicians, residents, nurses, nutritionist) patients ‐ 144 practices ‐ 2 firms
Interventions	Intervention group: Professional intervention (distribution of educational materials (guidelines) + educational meetings + local consensus processes + audit and feedback) Control group: usual care Length of intervention: 15 months
Outcomes	PROCESS: Compliance with standards of care: ‐Annual urine test for albumin/protein ‐Annual cholesterol determination ‐Annual diabetes education ‐Annual dilated retinal exam ‐Annual influenza vaccinations ‐Annual nutrition education PATIENT: HbA1c
Notes	Guidelines were locally developed by residents and faculty ‐directed at adjustments in treatment and monitoring ‐target: improvement of glycaemic control and compliance with recommended standards
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	D ‐ Not used