Schiel 2007.

Methods	Parallel randomised controlled clinical trial Randomisation ratio: 1:1:1 Superiority design
Participants	Inclusion criteria: people with type 2 diabetes with inadequate glycaemic control (HbA1c ≥ 8.0% or FBG ≥ 6.6 mmol/L) on premix insulin therapy (≤ 5 years), diabetes duration > 5 years, BMI 27‐35 Exclusion criteria: impaired hepatic or renal function, pregnancy, unable to understand the study, to cope or attend follow‐up visits Diagnostic criteria: not stated
Interventions	Number of study centres: 1 Treatment before study: mix insulin 75/25 or 70/30 A: 77.6 (32.1) , B: 64.9 (32.1), C: 65.2 (34.2) IU/day Titration period: 4 weeks
Outcomes	Primary outcome(s) (as stated in the publication): fasting blood glucose, HbA1c, treatment satisfaction, hypoglycaemia, adverse events, blood pressure, creatinine, liver enzymes
Study details	Total study duration: 20 weeks (4 + 16 wks) Run‐in period: 4 weeks Study terminated early (for benefit/because of adverse events): no
Publication details	Language of publication: English Funding source: Sanofi‐Aventis Publication status: peer review journal
Stated aim of study	Quote from publication: "To establish whether insulin plus OADs is effective in type 2 diabetes patients previously poorly controlled on premixed insulin therapy."
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote from publication: "Randomization was performed..."
Allocation concealment (selection bias)	Low risk	Quote from publication: "Randomization was performed by a central computer and patients were assigned (1:1:1) to one of the three treatment groups."
Blinding of participants and personnel (performance bias) Adverse events	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of participants and personnel (performance bias) Health‐related quality of life, patient satisfaction	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of participants and personnel (performance bias) HbA1c, FPG, lipids	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of participants and personnel (performance bias) Insulin dose	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of outcome assessment (detection bias) Adverse events	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of outcome assessment (detection bias) Health‐related quality of life, patient satisfaction	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of outcome assessment (detection bias) HbA1c, FPG, lipids	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Blinding of outcome assessment (detection bias) Insulin dose	High risk	Quote from publication: "In a open, controlled, randomised, parallel‐group, single‐centre, 16‐weeks pilot study..."
Incomplete outcome data (attrition bias) Adverse events	Low risk	Comment: data on weight gain and hypoglycaemia were collected and reported
Incomplete outcome data (attrition bias) Health‐related quality of life, patient satisfaction	Low risk	Comment: data on patient satisfaction were collected and reported
Incomplete outcome data (attrition bias) HbA1c, FPG, lipids	Low risk	Comment: outcome data were collected and reported
Incomplete outcome data (attrition bias) Insulin dose	Low risk	Comment: data on insulin dose were collected and reported
Selective reporting (reporting bias)	Low risk	Comment: all outcomes of interest were reported
Other bias	Unclear risk	Comment: funded by a pharmaceutical company