Rickheim 2002.

Study characteristics
Methods	Assessment of group versus individual diabetes education: a randomized study RCT (NA clusters and NA providers), conducted in 1) The programme was delivered in a large outpatient diabetes centre (the International Diabetes Center, Park Nicollet Institute, Minneapolis, Minnesota) using a classroom setting for the groups and individual consult rooms for individual sessions. 2) A diabetes nurse specialist (RN) and diabetes nutrition specialist (RD) presented all 4 sessions in both settings. In United States of America. 2 arms: 1. Control (group educational settings) (control arm) and 2. Intervention (individual educational settings) (intervention arm)
Participants	Control arm N: 87 Intervention arm N: 83, NA, NA Diabetes type: 2 Mean age: 52.5 ± 9 % Male: 34.1 Longest follow‐up: 6 months
Interventions	Control arm: (group educational settings) 1) Case management 2) Team change 3) Patient education 4) Promotion of self‐management Intervention arm: (individual educational settings) 1) Case management 2) Team change 3) Patient education 4) Promotion of self‐management
Outcomes	Glycated haemoglobin
Funding source	This research was funded by a grant from the Park Nicollet Institute, Park Nicollet Health Services, and an unrestricted educational grant from the American Association of Diabetes Educators, provided by Pfizer. Roche Diagnostics supplied blood glucose meters free of charge to all study participants.
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Patients randomised in the order of scheduling. Participants were then randomly assigned to either a group or individual setting in block sizes of 6. The first 3 consecutive participants were assigned to the group setting, with the next 3 participants assigned to the individual setting. After the first year of recruitment, block size was increased to 10 to increase efficiency in scheduling while maintaining random and equal opportunity for allocation.
Allocation concealment (selection bias)	High risk	Allocation is predictable. The first 3 consecutive participants were assigned to the group setting, with the next 3 participants assigned to the individual setting.
Patient's baseline characteristics (selection bias)	Low risk	Table 1. All demographic data have P values above 0.05.
Patient's baseline outcomes (selection bias)	High risk	Table 1. HbA1c has a significant P value (< 0.01) as well as weight (0.02). With the exception of weight and HbA1c, baseline data on these participants did not differ significantly by educational setting.
Incomplete outcome data (attrition bias)	High risk	They lost 78 patients out of 170 (45.9%). The retention rate for the study participants was 54% at the 6‐month follow‐up visit, suggesting a need to better assess reasons for dropout from the education programme. To quantify these issues, they queried a subset of participants that did not return for the 6‐month follow‐up visit. These participants indicated a number of consistent reasons for withdrawal from the education programme, such as relocation, a schedule that would not permit them to leave work, other family commitments, or the perception that they were doing well and did not see the value in returning.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Our outcome of interest was objectively assessed (HbA1c).
Selective reporting (reporting bias)	Unclear risk	No registered protocol. However methods mention data were collected at baseline, 2 weeks, 3 months and 6 months for all patients entering the education programme, but only baseline and 6‐month values are reported in results.
Risk of contamination (other bias)	Low risk	Equivalence study. Both groups received the same education intervention, but that was planned this way.
Other bias	Low risk	None.