Voigt 2018.

Study characteristics
Methods	Study design: retrospective cohort longitudinal Location: Germany Time period: 1987 to 2014 Outcome: PDR Outcome measurement: incidence
Participants	Number of participants: 2272 Diabetes type: T2D Inclusion criteria: fundoscopy reports of three consecutive years available Exclusion criteria: clinically significant macular oedema
Notes	Link to data extraction table, risk of bias assessment, and results: osf.io/w3dvg/?view_only=70d6e41449714f8ab22dd70306e3b936
Item	Authors' judgement	Support for judgement
Study participation	Unclear	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	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	Unclear	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