SDIS Study 1988.

Methods	Study design: parallel RCT Study duration (recruitment): not reported Follow‐up period: 90 months
Participants	Country: Sweden Setting: single centre Patients with type 1 diabetes and CKD stage 1; non proliferative retinopathy; normal SCr; high blood glucose concentrations Number: treatment group (48); control group (54) Mean age ± SD (years): treatment group (30 ± 8); control group (32 ± 7) Sex (M/F): treatment group (26/22); control group (28/26) Exclusion criteria: not reported
Interventions	Treatment group Education + 3 insulin injections daily Control group Standard treatment
Outcomes	Diabetic control Retinopathy Kidney function Death
Notes	Funding source: Novo‐Nordisk, Boehringer‐Mannheim Scandinavia and the Swedish Medical Research Council (06615)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information to permit judgement
Allocation concealment (selection bias)	Low risk	Closed identical envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not centrally determined outcome measurements
Incomplete outcome data (attrition bias) All outcomes	Low risk	6/102 lost to follow‐up (6%)
Selective reporting (reporting bias)	Low risk	All outcome data reported
Other bias	High risk	Funded by Novo‐Nordisk, Boehringer‐Mannheim Scandinavia