Lujan 2007.

Methods	Parallel randomised controlled clinical trial (RCT) Randomisation ratio: 1:1 Superiority design
Participants	Inclusion criteria: 40 years of age or older Self‐reported Mexican American ethnicity Diagnosed with type 2 diabetes for at least 1 year Taking or having taken hypoglycaemic agents within the past 6 months Willing to participate Non‐completion of a formal diabetes education programme at the clinic Ability to speak English or Spanish Exclusion criteria: Have type 1 diabetes Younger than 40 years of age Diagnosed with diabetes for less than 1 year Being treated for complications that would interfere with ability to participate in classes In addition, only 1 participant per household was eligible to participate in the trial Diagnostic criteria: no mention
Interventions	Number of study centres: 1 Treatment before study: Taking or having taken hypoglycaemic agents within the past 6 months Intervention: ran by "promotoras." Consisting of 8 × weekly 2‐hour participative group classes and fortnightly telephone follow‐up. Following the end of the classes, inspirational faith‐based health behaviour change postcards were sent to participants fortnightly. Eight group sessions covered the following topics: Diabetes: causes, diagnosis, incidence and prevalence Blood glucose testing, hyperglycaemia and hypoglycaemia HbA1c definition, reference range, foot care Eye care, how to read labels Dental care and sick day guidelines Long‐term complications of diabetes Hypertension and diabetes Cardiovascular complications of diabetes Classes were interactive, small‐group sessions (23 participants in Spainsh classes, 6 in English class) involving hands‐on demonstrations and handouts Telephone call by promotoras to answer questions and reinforce education Postcards with a faith‐based and health behaviour change message were sent fortnightly after the sessions ended
Outcomes	Outcomes reported in abstract of publication: HbA1c, diabetes knowledge and diabetes health beliefs
Study details	Run‐in period: no mention of this Study terminated before regular end: no
Publication details	Language of publication: English Funding: supported by a grant from the Paso del Norte Health Foundation through the Center for Border Health Research Publication status: peer‐reviewed journal
Stated aim of study	The purpose of this RCT is to determine the effectiveness of an intervention led by promotoras (CHWs) on glycaemic control, diabetes knowledge and diabetes beliefs of Mexican Americans with type 2 diabetes living in a major city on the Texas‐Mexico border
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: not stated; just says "were randomised"
Allocation concealment (selection bias)	Unclear risk	Comment: no mention
Blinding of participants and personnel (performance bias) Objective outcomes	High risk	Comment: does not say but likely not blinded
Blinding of participants and personnel (performance bias) Subjective outcomes	High risk	Comment: does not say but likely not blinded
Blinding of outcome assessment (detection bias) Lab tests: Lipids, HBA1C	Low risk	Comment: lack of blinding unlikely to affect outcome
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	Quote from publication: "A trained bilingual assistant, masked to the intervention and group assignment, read the questionnaires to each participant" Comment: however, participant still likely not blinded
Incomplete outcome data (attrition bias) Objective outcomes	Low risk	Comment: overall attrition rate was 6% (n = 9). No mention of intention‐to‐treat analysis
Incomplete outcome data (attrition bias) Subjective outcomes	Low risk	Quote from publication: "data from participants who missed more than 2 of 8 classes or did not complete at least 3 data collection assessment interviews were discarded..." Comment: overall attrition rate was 6% (n = 9). No mention of intention‐to‐treat analysis
Selective reporting (reporting bias)	Unclear risk	Comment: all outcomes reported but no protocol seen
Other bias	Unclear risk	Comment: none