Table 1.

Inclusion and exclusion criteria in the personalised variable-interval risk-based screening for diabetic retinopathy randomised controlled trial

Inclusion criteria	Exclusion criteria
Adults, young people and children who are aged ≥12 years.	Under age 12 years.
Due to be offered an appointment for retinal screening during the recruitment period.
Registered with a participating GP practice.	Are not registered with a participating GP practice.
Are included in the study data warehouse (have not opted out).	Have opted out from the study data warehouse.
Have no retinopathy or have retinopathy and maculopathy less than the definition of screen positive diabetic retinopathy.	Have screen positive diabetic eye disease or significant other eye disease requiring referral to the HES.
Have gradeable digital retinal images in both eyes.	Are ineligible for screening for whatever reason, including having ungradable digital retinal images, which includes patients who have only one eye or an ungradable eye with no visual potential.
Give their informed consent for participation.	Do not give consent for participation in the RCT.
Are not involved in any trial investigating a treatment aiming at preventing or modifying the development of STDR.	Are involved in any trial investigating a treatment aiming at preventing or modifying the development of STDR.

GP, general practitioner; HES, hospital eye service; STDR, sight-threatening diabetic retinopathy.