Rubak 2011.

Study characteristics
Methods	Effect of "motivational interviewing" on quality of care measures in screen detected type 2 diabetes patients: a one‐year follow‐up of an RCT, ADDITION Denmark Clustered RCT (80 clusters and 140 providers), conducted in 1) This study included practices/GPs from the intensive arm of ADDITION Denmark from 2 counties in DK 2) Intervention delivered to GPs by trained teacher in Denmark 2 arms: 1. Control (C‐group, no training) (control arm) and 2. Intervention (I‐group, MI training) (intervention arm)
Participants	Control arm N: 321 Intervention arm N: 307, NA, NA Diabetes type: 2 Mean age: 61 ± NR % Male: 58 Longest follow‐up: 12 months
Interventions	Control arm: (C‐group, no training) 1) Clinician education Intervention arm: (I‐group, MI training) 1) Clinician education
Outcomes	Anti‐platelet drugs Lipid‐lowering drugs Antihypertensive drug Glycated haemoglobin Systolic blood pressure Diastolic blood pressure Low‐density lipoprotein Hypertension control Smoking status
Funding source	The ADDITION trial was supported by the National Health Services in the counties of Copenhagen, Aarhus, Ringkoebing, Ribe and South Jutland in Denmark, Danish Research Foundation for General Practice, Danish Centre for Evaluation and Health Technology Assessment, the Diabetes Fund of the National Board of Health, the Danish Medical Research Council, the Danish Medical Association Research Fund, the Diabetes Association's Foundation for Scientific Research, the Aarhus University Research Foundation, and Novo Nordisk Foundation. Furthermore the trial has been given unrestricted grants from Novo Nordisk AS, Novo Nordisk Scandinavia AB, ASTRA Denmark, Pfizer Denmark, GlaxoSmithKline Pharma Denmark, SERVIER Denmark A/S, and HemoCue Denmark A/S.
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised by the project manager using the method "drawing lots".
Allocation concealment (selection bias)	Low risk	Cluster. Randomisation was stratified by county, size of practices and by numbers of full‐time GPs.
Provider's baseline characteristics (selection bias)	Unclear risk	Not reported.
Patient's baseline characteristics (selection bias)	Low risk	No significant differences between the groups.
Patient's baseline outcomes (selection bias)	Unclear risk	Not reported.
Incomplete outcome data (attrition bias)	Unclear risk	Two practices (6 GPs) and 2 type 2 diabetes patients dropped out after randomisation. 13 participants in the control group (10%) and 18 in the intervention group (13%) did not complete 1‐year follow‐up. The number of GPs and patients that dropped out of the study after randomisation is not expected to bias the results in consideration of the total number of GPs and patients included in this study. 6 GPs lost in control group.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Unclear risk	Mix of subjective and objective measures. Objective for HbA1c, LDL, BP and medications. Subjective for smoking status.
Selective reporting (reporting bias)	High risk	Retrospectively registered protocol. Outcomes in protocol do not match outcomes published.
Risk of contamination (other bias)	Low risk	Cluster‐randomised.
Other bias	Unclear risk	This study may suffer from a limitation because training in MI was performed by only one person. This makes outcome highly dependent on this person's teaching methods and capacity to train the GPs. The study did not include blinding of behavioural changes and may therefore be influenced by the Hawthorne effect.