Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Trial website

Contact information



Primary contact

Prof Peter Scanlon


Contact details

Gloucestershire Diabetic Retinopathy Research Group
Office above Oakley Ward
Cheltenham General Hospital
Sandford Road
GL53 7AN
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

HTA Project: 10/66/01

Study information

Scientific title

Development of a cost-effectiveness model for optimization of the screening interval in diabetic retinopathy screening.



Study hypothesis

1. Use demographic and routinely collected clinical information from 15000 patients in 85 Gloucestershire GP practices to develop a risk score for each patient and to identify patient groups whose risk of retinopathy progression is low and whose screening interval can be safely extended
2. Model what the influence of the grading classification error is on over referrals and under referrals and how that influence changes over time, taking into account sequential grading results and hospital outcome results, comparing screening intervals that vary according to risk score against current standard practice (annual screening intervals for all patients) and other fixed-interval approaches.
3. Extend our results to multi-ethnic populations using a dataset of 2000 Asians and 5000 Caucasians from Coventry and Warwickshire and a South London dataset of 2000 people with diabetes including 700 people of African Caribbean origin. Grading results can be made available from these datasets for at least a 3 year period. The risk score and algorithm will be tested against retinopathy grades in the two datasets where follow-up data is available
4. Determine if assigning diabetic patients to differing diabetic retinopathy screening intervals using a risk estimation model is cost-effective when compared to current practice, which is annual screening of all eligible patients with diabetes
5. Estimate the economic benefits if personalised screening intervals were to be applied to the National Screening Programme in England

More details can be found at

Ethics approval

Not provided at time of registration

Study design

A primary research study using routinely collected clinical data to model the clinical efficacy and cost-effectiveness of variable screening intervals.

Primary study design


Secondary study design

Cross-section survey

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Diabetic Retinopathy


The Health Technology being assessed is a variable screening interval based on risk of diabetic retinopathy (DR) assessed using two field digital photographs after pupil dilation as used in the English National Screening Programme (ENSPDR) and other available clinical data.

Intervention type



Not Applicable

Drug names

Primary outcome measures

A risk-based algorithm for screening interval

Secondary outcome measures

1. Years of sight saved
2. Quality-Adjusted Life Years (QALYs) gained
3. Key recommendations for further research

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Participants over the age of 12 years
2. Diagnosed with diabetes and have attended a diabetic retinopathy screening programme in one of the study areas of Gloucestershire, Coventry and Warwickshire, South London and Nottingham.
3. Have been sent the required information about transfer of risk factor data as advised by the Department of Health funded GP2DRS (‘General Practice to Diabetic Retinopathy Screening’) Project and they would have been given the opportunity to inform their General Practice or Screening Programme that they did not want their risk factor data transferred.
4. The participants in this study are pseudoanonymised data on those people who have attended for screening and risk factor data has been transferred according to the recommended guidelines of the GP2DRS project.

Participant type


Age group




Target number of participants

Total 24,000 -15,000 in Gloucestershire, 7000 from Coventry including 2000 Asians and 2000 from South London including 700 people of Afro-Caribbean origin .

Participant exclusion criteria

1. People with diabetes under 12 years
2. Those who have not attended for screening
3. Those people who have indicated that they do not want their risk factor data transferred to the screening services.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Gloucestershire Diabetic Retinopathy Research Group
GL53 7AN
United Kingdom

Sponsor information


Gloucestershire Hospitals NHS Foundation Trust (UK)

Sponsor details

c/o Mr Mark Walker
Trust Headquarters
1 College Lawn
GL53 7AG
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

NIHR Health Technology Assessment Programme - HTA (UK) ref: 10/66/01

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes