Fonseca 2007.
| Methods |
Parallel randomised controlled clinical trial Randomisation ratio: 1:1 Superiority design |
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| Participants |
Inclusion criteria: participants had to have received only injectable insulin for at least 3 months, at a dose of at least 30 U/day for a minimum of 4 weeks prior to enrolment. Age 18‐80 years, HbA1c 7.5‐11.0%, fasting plasma glucose < 15 mmol/L and BMI 22‐45 kg/m² Exclusion criteria: people with type 1 diabetes, diabetes resulting from pancreatic injury or secondary forms of diabetes. People with acute metabolic diabetic complications within the past 6 months, serious cardiac conditions or clinically significant liver disease. Any of the following laboratory abnormalities: alanine transaminase > 3 x the upper limit of normal; direct bilirubin > 1.3 x the upper limit of normal; serum creatinine > 220 μmol/L; fasting triacylglycerol > 7.9 mmol/L Diagnostic criteria: based on the investigator's diagnosis and on the patient's medical record |
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| Interventions |
Number of study centres: 68 Treatment before study: insulin: intervention 81.2 ± 44.8 U/day and control 81.9 ± 49.4 U/day Titration period: 4 weeks |
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| Outcomes | Primary outcome(s) (as stated in the publication): glycaemic control (HbA1c, fasting plasma glucose), insulin dose and number of injections, fasting lipids, bodyweight | |
| Study details |
Total study duration: 24 weeks Run‐in period: 4 weeks Study terminated early (for benefit/because of adverse events): no |
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| Publication details |
Language of publication: English Funding source: Novartis Publication status: peer‐reviewed journal |
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| Stated aim of study | Quote from publication: "To assess the efficacy and tolerability of vildagliptin added to added to insulin therapy in patients with type 2 diabetes." | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Comment: not possible to judge whether the sequence generation was adequate |
| Allocation concealment (selection bias) | Unclear risk | Comment: not possible to judge whether the allocation to the intervention and control group was concealed |
| Blinding of participants and personnel (performance bias) Adverse events | Low risk |
Quote from publication: "This was a 24‐week, randomised, double‐blind, placebo‐controlled, parallel‐group study...." Comment: probably the participants and the personnel were blinded |
| Blinding of participants and personnel (performance bias) HbA1c, FPG, lipids | Low risk |
Quote from publication: "All assessments were made by central laboratories." Comment: probably the participants and the personnel were blinded |
| Blinding of participants and personnel (performance bias) Insulin dose | Low risk |
Quote from publication: "This was a 24‐week, randomised, double‐blind, placebo‐controlled, parallel‐group study...." Comment: probably the participants and the personnel were blinded |
| Blinding of outcome assessment (detection bias) Adverse events | Unclear risk | Comment: unclear if the outcome assessor was blinded |
| Blinding of outcome assessment (detection bias) HbA1c, FPG, lipids | Unclear risk | Comment: unclear if the outcome assessor was blinded |
| Blinding of outcome assessment (detection bias) Insulin dose | Unclear risk | Comment: unclear if the outcome assessor was blinded |
| 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) HbA1c, FPG, lipids | Low risk | Comment: data on all outcome measures were collected and reported |
| Incomplete outcome data (attrition bias) Insulin dose | Low risk | Comment: data on insulin dose was collected and reported |
| Selective reporting (reporting bias) | Unclear risk | Comment: post‐treatment BMI not reported |
| Other bias | Unclear risk | Comment: funded by a pharmaceutical company |