Anderson 2005.

Study characteristics
Methods	Evaluating a problem‐based empowerment program for African Americans with diabetes: results of a randomized controlled trial RCT (NA clusters and NA providers), conducted in 1) The primary intervention was held in convenient community‐based locations (randomised part). The follow‐up was done at the same place or through phone calls (non‐randomised part). 2) Certified diabetes educators (dietitians and nurses) delivered intervention. In United States of America. 2 arms: 1) Control (wait‐list) (control arm) and 2) Intervention (group education: problem‐based empowerment program) (intervention arm)
Participants	Control arm N: 114 Intervention arm N: 125, NA, NA Diabetes type: 2 Mean age: 61 ± 11.9 % Male: 18 Longest follow‐up: 1.38 months
Interventions	Control arm: (wait‐list) 1) Facilitated relay of clinical information Intervention arm: (group education: problem‐based empowerment programme) 1) Case management 2) Team change 3) Facilitated relay of clinical information 4) Patient education 6) Promotion of self‐management
Outcomes	1) Glycated haemoglobin 2) Systolic blood pressure 3) Diastolic blood pressure
Funding source	This study was supported by National Institutes of Health Grants R01 DK53994‐01 and the Core(s) of the Michigan Diabetes Research and Training Center (NIH5P60 DK20572) from the National Institute of Diabetes and Digestive and Kidney Diseases
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported. Patients were randomly assigned to either the intervention group or the wait‐listed control group.
Allocation concealment (selection bias)	Unclear risk	Not reported.
Patient's baseline characteristics (selection bias)	Low risk	Table 3 shows mean values or percent distributions for demographic variables as well as selected laboratory, psychosocial and health variables at baseline. The intervention and control patients did not differ significantly on any of these measures.
Patient's baseline outcomes (selection bias)	Low risk	Table 3 shows mean values or percent distributions for demographic variables as well as selected laboratory, psychosocial and health variables at baseline. The intervention and control patients did not differ significantly on any of these measures.
Incomplete outcome data (attrition bias)	Low risk	Table 4. They have HbA1c data for 225 patients out of 239 at 6 weeks (5.9% lost), 222 for SBP (7.1% lost) and 220 for DBP (8.0% lost). Reasons and numbers in each arms not reported.
Blinding of participants and personnel (performance bias) and of outcome assessors (detection bias)	Low risk	Objective outcomes (HbA1c, SBP and DBP).
Selective reporting (reporting bias)	Unclear risk	No registered protocol or previously published protocol. They did not report data on HDL, LDL and triglycerides in Table 4 (for each arm) as they did in Table 5 (arms combined).
Risk of contamination (other bias)	Unclear risk	The control group improved HbA1c level during the 6 weeks. We believe that both groups changed because of the combination of volunteer bias (patients were better insured and educated and exhibited better self‐management), study effects (increased frequency of providing patients and their physicians data over the one‐year study period), and programme impact (unable to demonstrate a statistically significant impact of the intervention). Although control group did not receive the intervention at the same time as intervention group, "The control group made the decision to improve their diabetes self‐management during the control period."
Other bias	Low risk	No evidence of other bias.