Roy 2006.

Study characteristics
Methods	Study design: prospective cohort longitudinal Location: USA Time period: original cohort 1993 to 1998; follow‐up after 6 years Outcome: PDR and HRC‐PDR Outcome measurement: incidence and OR
Participants	Number of participants: 725 Diabetes type: T1D Inclusion criteria: African Americans with T1D; treated with insulin before 30 years of age, and who were receiving insulin at time of study; participated in the New Jersey 725 study 1993 to 1998 Exclusion criteria: T2D; diagnosed after 30 years; maturity‐onset diabetes of youth
Notes	Link to data extraction table, risk of bias assessment, and results: osf.io/z84e5/?view_only=0192b34ce2654bd2ac33e8c8b02e5754
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	Yes	See ‘Notes’ above for link to risk of bias assessment
Adjustment for other prognostic factors	Unclear	See ‘Notes’ above for link to risk of bias assessment
Statistical analysis and reporting	Yes	See ‘Notes’ above for link to risk of bias assessment