Vesteinsdottir 2010.

Study characteristics
Methods	Study design: retrospective cohort longitudinal Location: Iceland Time period: not reported Outcome: PDR Outcome measurement: incidence
Participants	Number of participants: 76 Diabetes type: T1D and T2D Inclusion criteria: diabetes; having regular retinopathy screening; PDR in one or both eyes Exclusion criteria: not reported
Notes	Link to data extraction table, risk of bias assessment, and results: osf.io/crwxa/?view_only=2a40812ea9bd4739baa4dae8f8f597bb
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	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