Incentives in diabetic eye assessment by screening

ISRCTN	ISRCTN14896403
DOI	https://doi.org/10.1186/ISRCTN14896403
Protocol serial number	REC 14/LO/1779
Sponsor	Imperial College London
Funder	National Institute for Health Research

Submission date: 01/12/2014
Registration date: 25/02/2016
Last edited: 07/03/2023

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Eye Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
Diabetes is becoming an increasing health problem around the world. People with diabetes are at risk of sight loss, from a condition called diabetic retinopathy. This happens when tiny blood vessels in the eye bleed, which destroys the retina. It is estimated that in England every year 4,200 people are at risk of blindness caused by diabetic retinopathy and there are 1,280 new cases of blindness caused by diabetic retinopathy. Once people experience symptoms, the disease is already advanced and may be difficult to treat, however, with early diagnosis and treatment, the risk of blindness can be dramatically reduced. In order to prevent avoidable blindness in people with diabetes, eye screening is essential. People with diabetes are invited to eye screening appointments every year. However, rates of attendance at these appointments vary between different areas, and those with the highest risk of sight damage are also those with lowest levels of attendance at screening appointments. The NHS needs simple, inexpensive and cost effective strategies are required by the NHS to influence health behaviours (for example, to increase the number of people attending screening programmes). This has relevance to diabetic eye screening but also more widely as the NHS increasingly tries to prevent disease rather than simply treat it. This study is looking at the impact of different types of financial incentives on encouraging people with diabetes to attend their eye screening appointments. The incentives being tested are a £10 reward, or being entered into a lottery to win £1000.

Who can participate?
People aged sixteen and over with diabetes, who have been invited to eye screening appointments in the past but who have not attended, or tried to rearrange their appointment.

What does the study involve?
People who are eligible for the study are randomly allocated to one of three groups. Participants in the first group (the control group) receive the usual letter, inviting them to an eye screening appointment. Participants in the second group are sent an appointment letter also offering them £10 if they attend their appointment. Participants in the third group are sent an appointment letter, also offering them the opportunity to be entered into a lottery for £1000 if they attend their appointment. The screening procedure involves drops being put into the eye, and a photograph being taken of the eye.

What are the possible benefits and risks of participating?
The benefit of participating is that if a participant is developing diabetic retinopathy, the screening can detect it early, so it can be treated to prevent it leading to blindness. Risks include the eyes being more sensitive to sunlight immediately after the screening procedure and participants should not drive after the appointment, as the drops may affect vision for a short time.

Where is the study run from?
The study is run from the Diabetic Eye Screening Programme managed by 1st Retinal Screen Ltd. There are two screening locations in London, one in Chelsea and Westminster Hospital, and one in St Marys Hospital.

When is the study starting and how long is it expected to run for?
May 2014 to August 2016

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Mrs Gaby Judah

Contact information

Mrs Gaby Judah
Scientific

Imperial College London
Division of Surgery
10th Floor, QEQM Building
St Mary's Campus
Praed Street
Paddington
London
W2 1NY
United Kingdom

Study information

Primary study design	Interventional
Study design	Single centre randomised controlled trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Incentives in Diabetic Eye Assessment by Screening (IDEAS) Trial
Study acronym	IDEAS
Study objectives	1. Are incentives an effective strategy to encourage participation in the screening programme? 2. Does the design of the financial incentive scheme affect its effectiveness in influencing participation in health screening? 3. Does the choice of incentive scheme, if successful, attract patients who have a different demographic or socioeconomic status to those who attend screening regularly? 4. Is offering these incentives a cost-effective strategy for enhancing participation?
Ethics approval(s)	National Research Ethics Committee (London - Riverside), 14/10/2014, ref: 14/LO/1779
Health condition(s) or problem(s) studied	Diabetic retinopathy
Intervention	Participants are randomly allocated to one of three groups: Group 1 – Control Group: Standard invitation letter from the Screening Service . Group 2 – Fixed Incentive: Standard invitation letter but with additional text offering a financial incentive (£10) after screening is completed. Group 3 – Probabilistic Incentive: Standard invitation letter but with additional text offering a financial incentive (lottery offering 1% chance to win £1000).
Intervention type	Behavioural
Primary outcome measure(s)	Attendance at the screening appointment. This will be recorded at the appointment (which takes place four weeks after the invitation letter is sent), by the screener entering the patient into the electronic appointment record database. Following the end of data collection a search will be conducted on the database to extract information on attendance, as well as other demographic variables, and information on rearranged appointments.
Key secondary outcome measure(s)	1. Assess which incentive scheme is most effective 2. The cost effectiveness of different incentives on increasing uptake. 3. The impact on equity - whether incentives may encourage different groups to attend screening that may otherwise have not. A measure of social deprivation status will be calculated from the postcode. The impact of distance from the screening centre and GP practice will aslo be considered. 4. The effect of the different interventions on the number of participants who actually consent to the screening procedure once they attend the screening clinic 1st Retinal Screen Ltd will provide the anonymised data including the cohort’s age, gender, deprivation status (calculated from postcode), and ethnicity (subject to availability). The data will be provided following the screening of all participants. If there are significant differences in screening uptake and the demographic/risk factor profile between incentive schemes then a more detailed calculation of the impact of incentives is planned.
Completion date	01/08/2016

Eligibility

Participant type(s)	Patient
Age group	Other
Sex	All
Target sample size at registration	1000
Key inclusion criteria	Patients, aged 16 and older, who were invited to screening in the last 24 months on a yearly basis and failed to attend or contact the screening service to rearrange an appointment will be studied.
Key exclusion criteria	1. Participants under the age of 16 2. Participants who have attended screening appointments in the past, or contacted the service to rearrange an appointment
Date of first enrolment	02/01/2015
Date of final enrolment	31/12/2015

Locations

Countries of recruitment

United Kingdom
England

Study participating centre

1st Retinal Screen Ltd

London
W2 1NY
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not expected to be made available
IPD sharing plan	Not provided at time of registration

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/03/2017		Yes	No
Results article		23/08/2018	07/03/2023	Yes	No
Protocol article	protocol	18/03/2016		Yes	No
HRA research summary			28/06/2023	No	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes

Editorial Notes

07/03/2023: Publication reference added.
05/04/2017: Publication reference added.
21/03/2016: Publication reference added.