Noto 2016.

Study characteristics
Methods	Cluster‐randomized trial to improve the quality of diabetes management: The study for the efficacy assessment of the standard diabetes manual (SEAS‐DM) Clustered RCT (42 clusters and 42 providers), conducted in 1) The present study was carried out in eight domestic districts of the Japan Medical Associations. 2) Clinical research co‐ordinators, who were not aware of the allocation of the PCPs, visited each clinic every 3 months and collected the pertinent data by reviewing the medical records. In Japan. 2 arms: 1. Control group (Diabetes Treatment Guide) (control arm) and 2. Intervention group (Diabetes Treatment Guide + The Manual) (intervention arm)
Participants	Control arm N: 182 Intervention arm N: 234, NA, NA Diabetes type: 2 Mean age: 62.29 ± NR % Male: 58.43 Longest follow‐up: 12 months
Interventions	Control arm: (Diabetes Treatment Guide) 1) Clinician education Intervention arm: (Diabetes Treatment Guide + The Manual) 1) Clinician education
Outcomes	Glycated haemoglobin
Funding source	This study was supported by Grants‐in‐Aid from the Japan Agency for Medical Research and Development (Grant: Practical Research Project for Life‐Style related Diseases including CVD and Diabetes), and from the Ministry of Health, Labour and Welfare, Japan (Grant number: Comprehensive Research on Life‐Style Related Diseases including CVD and Diabetes H25‐016).
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The PCPs in each district were randomly allocated to either an intervention or a control group, with each group as a cluster and each district as a stratum.
Allocation concealment (selection bias)	Low risk	Cluster‐RCT.
Provider's baseline characteristics (selection bias)	Unclear risk	Not reported.
Patient's baseline characteristics (selection bias)	Low risk	Table 1. All P values greater than 0.05.
Patient's baseline outcomes (selection bias)	Low risk	Table 1. Outcomes look balanced.
Incomplete outcome data (attrition bias)	Low risk	Figure 1. 1 control patient and 4 intervention patients lost. Reasons given. During the 1‐year follow‐up period, 5 patients were lost to follow‐up: the follow‐up rate was 99.8% (Figure 1).
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Objective measure for HbA1c.
Selective reporting (reporting bias)	High risk	Protocol does not mention HbA1c measurement or the adherence to the following recommendation‐concordant performances: measurement of HbA1c (every 3 months), blood pressure (every 3 months) and serum lipids (every 3 months).
Risk of contamination (other bias)	Low risk	The PCPs were not notified of the study endpoints at any point during the study period. Cluster‐RCT.
Other bias	Low risk	None identified.