Verdaguer 2009.

Study characteristics
Methods	Study design: retrospective cohort longitudinal Location: Chile Time period: 1971 to 2008 Outcome: PDR Outcome measurement: incidence, means and percentages of progressors versus non‐progressors to PDR, OR
Participants	Number of participants: 39 Diabetes type: T1D Inclusion criteria: T1D Exclusion criteria: not reported
Notes	Link to data extraction table, risk of bias assessment, and results: osf.io/vxnk2/?view_only=e3605c9776844cd2b6449037457ad5fd
Item	Authors' judgement	Support for judgement
Study participation	No	See ‘Notes’ above for link to risk of bias assessment
Study attrition	No	See ‘Notes’ above for link to risk of bias assessment
Prognostic factor measurement	No	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	No	See ‘Notes’ above for link to risk of bias assessment