Hovind 2003.

Study characteristics
Methods	Study design: prospective cohort Location: Denmark Time period: baseline: onset of T1D 1965 to 1984, followed until 2000 Outcome: PDR Outcome measurement: cumulative incidence
Participants	Number of participants: not reported Diabetes type: T1D Inclusion criteria: groups A to C ‐ all T1D patients at Hvidovre Hospital with onset of diabetes between 1965 and 1979, and before the age of 41 years, and who were 18 years of age at the time of study; group D ‐ all newly diagnosed T1D patients referred to the Steno Memorial Hospital between 1 September 1979 and 31 August 1984 Exclusion criteria: mentally ill; onset of other serious competing medical or psychosocial conditions
Notes	Link to data extraction table, risk of bias assessment, and results: osf.io/jmkeu/?view_only=cebee4c24f3042b8aa34e045b8acd90e
Item	Authors' judgement	Support for judgement
Study participation	Unclear	See ‘Notes’ above for link to risk of bias assessment
Study attrition	Unclear	See ‘Notes’ above for link to risk of bias assessment
Prognostic factor measurement	Unclear	See ‘Notes’ above for link to risk of bias assessment
Outcome measurement	Unclear	See ‘Notes’ above for link to risk of bias assessment
Adjustment for other prognostic factors	No	See ‘Notes’ above for link to risk of bias assessment
Statistical analysis and reporting	Unclear	See ‘Notes’ above for link to risk of bias assessment