van Bruggen 2008.

Study characteristics
Methods	Implementation of locally adapted guidelines on type 2 diabetes Cluster‐RCT (30 clusters), conducted in Apeldoorn, The Netherlands Two arms: 1. Control (control arm) and 2. Intervention (intervention arm)
Participants	Control arm N: 818 Intervention arm N: 822 Diabetes type: type 2 Mean age: 67.1 ± 11.6 % Male: 48.6 Longest follow‐up: 12 months
Interventions	Control arm: None Intervention arm: 1) Audit and feedback 2) Clinician education
Outcomes	1) HbA1c 2) SBP 3) DBP 4) Controlled hypertension (< 140/85 mmHg)
Funding source	AGIS insurance company
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Information not available.
Allocation concealment (selection bias)	Low risk	Information not available.
Provider's baseline characteristics (selection bias)	High risk	Not reported.
Patient's baseline characteristics (selection bias)	High risk	Except for education and the presence of macrovascular complications, patients’ characteristics were highly comparable across study groups.
Patient's baseline outcomes (selection bias)	Unclear risk	Table 1 ‐ no P values reported, but outcomes look balanced. Do not use statistical terms in text "Except for education and the presence of macrovascular complications, patients’ characteristics were highly comparable across study groups"
Incomplete outcome data (attrition bias)	Low risk	Information not available.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Information not available.
Selective reporting (reporting bias)	Low risk	Information not available.
Risk of contamination (other bias)	Low risk	Information not available.
Other bias	Unclear risk	Information not available.