Feinglos 1998.
| Methods |
Cross‐over randomised controlled clinical trial Randomisation ratio: 1:1 Superiority design |
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| Participants |
Inclusion criteria: insulin‐requiring type 2 diabetes, total daily insulin dose ≥ 40 units, insulin monotherapy ≥ 1 year prior to the study Exclusion criteria: not stated Diagnostic criteria: not stated |
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| Interventions |
Number of study centres: 1 Treatment before study: insulin NPH and regular 80.8 (range 40‐210) U/day Titration period: 1 week |
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| Outcomes | Primary outcome(s) (as stated in the publication): glycaemic control (plasma glucose, HbA1c), C‐peptide, plasma free insulin levels, lipoprotein (TC, TG, HDL, LDL, VLDL), insulin dose, BMI | |
| Study details |
Total study duration: 8 months Run‐in period: 1 week Study terminated early (for benefit/because of adverse events): no |
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| Publication details |
Language of publication: English Funding source: Pfizer Pharmaceuticals, Lifescan, National Center for Research Resources Publication status: peer‐reviewed journal |
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| Stated aim of study | Quote from publication: "To determine the effect(s) on glucose control, insulin dose and circulating insulin levels of the addition of a sulphonylurea (glipizide) to the treatment regimen of patients with insulin‐requiring type 2 diabetes mellitus." | |
| 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) HbA1c, FPG, lipids | Low risk |
Quote from publication: "This study was a double‐blind crossover comparison of insulin and placebo vs. insulin and glipizide." Comment: probably the participant and the personnel were blinded |
| Blinding of participants and personnel (performance bias) Insulin dose | Low risk |
Quote from publication: "This study was a double‐blind crossover comparison of insulin and placebo vs. insulin and glipizide." Comment: probably the participant and the personnel were blinded |
| Blinding of outcome assessment (detection bias) HbA1c, FPG, lipids | Unclear risk | Comment: it is unclear if the outcome assessor was blinded |
| Blinding of outcome assessment (detection bias) Insulin dose | Unclear risk | Comment: it is unclear if the outcome assessor was blinded |
| Incomplete outcome data (attrition bias) HbA1c, FPG, lipids | Low risk | Comment: all outcome data were collected and reported |
| Incomplete outcome data (attrition bias) Insulin dose | Low risk | Comment: all outcome data were collected and reported |
| Selective reporting (reporting bias) | Low risk | Comment: all outcomes of interest reported |
| Other bias | Unclear risk | Comment: funded by a pharmaceutical company |