Steno 1 1983.
| Methods |
Randomised controlled clinical trial (RCT) Randomisation ratio: 1:1 Superiority design |
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| Participants |
Inclusion criteria: type 1 diabetes with background retinopathy, postprandial C‐peptide ≤ 0.2 nmol/L, serum creatine ≤ 150 μmol/L, age 18‐51 years, diabetes onset before age 30, diabetes duration < 35 years Exclusion criteria: ‐ Diagnostic criteria: type 1 diabetes |
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| Interventions |
Number of study centres: 1 Treatment before study: 1‐3 insulin injections |
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| Outcomes | Outcomes reported in abstract of publication: mean blood glucose, HbA1c, retinal morphology, retinal function, proliferative retinopathy | |
| Study details |
Run‐in period: ‐ Study terminated before regular end: no |
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| Publication details |
Language of publication: English Funding: non‐commercial Publication status: peer‐reviewed journal/full article |
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| Stated aim of study | Quote from publication: "The aim of the study was to evaluate the effect of near‐normal glycaemic control on retinopathy" | |
| Notes | HbA1c: glycosylated haemoglobin level; IDDM: insulin‐dependent diabetes mellitus | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Quote from publication: "Patients were randomised to unchanged conventional treatment or to continuous subcutaneous insulin infusion". Comment: sequence generation not described |
| Allocation concealment (selection bias) | Unclear risk | Quote from publication: "Patients were randomised to unchanged conventional treatment or to continuous subcutaneous insulin infusion ". Comment: allocation concealment not described |
| Blinding of participants and personnel (performance bias) Objective Outcomes | Low risk | Comment: patients and investigators were not blinded, but risk of bias considered low for objective outcomes |
| Blinding of participants and personnel (performance bias) Subjective Outcomes | High risk | Comment: patients and investigators were not blinded |
| Blinding of outcome assessment (detection bias) Objective Outcomes | Low risk | Quote from publication: "At the end of the study all fundus photographs were mixed and read in a ‘blind’ fashion by two ophthalmologists who had to agree whether the photographs showed deterioration, no change, or improvement" Comment: blinded outcome assessment of retinopathy, unclear for other outcomes |
| Blinding of outcome assessment (detection bias) Subjective Outcomes | Unclear risk | Comment: not described |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Comment: all 30 patients were included in the analysis, but it is not clear whether there were missing data and how they were treated |
| Selective reporting (reporting bias) | Unclear risk | Comment: there is insufficient information to assess whether a risk of selective outcome reporting is present |
| Other bias | Unclear risk | Comment: HbA1c baseline difference between treatment groups, inconsistencies regarding number of enrolled patients across publications |