A feasibility study of the use of a cataract surgery decision aid which includes personalised estimates of risks and benefits

ISRCTN	ISRCTN11309852
DOI	https://doi.org/10.1186/ISRCTN11309852
ClinicalTrials.gov (NCT)	Nil known
Clinical Trials Information System (CTIS)	Nil known
Integrated Research Application System (IRAS)	246649
Protocol serial number	IRAS Project ID: 246649
Sponsor	University Hospitals Bristol NHS Foundation Trust
Funder	NIHR

Submission date: 01/12/2018
Registration date: 16/05/2019
Last edited: 20/08/2025

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
Cataract surgery is the most frequently undertaken NHS surgical procedure with around 450,000 operations taking place in the UK each year. At the moment, potential levels of benefit and risk of cataract surgery are routinely explained to patients in general terms only (i.e. a potential level of risk based on what is known about the average population). The research team have developed a leaflet, called a Cataract Decision Aid, which presents information that is specific to you as an individual. The Cataract Decision Aid explains personalised levels of benefit and risk of cataract surgery, based on certain features related to your health, medical history and age, and how much your vision is affected by your cataract. It also includes some frequently asked questions about cataract and cataract surgery.

Who can participate?
Anyone who has a cataract and has been referred for an assessment and discussion about whether to go ahead with cataract surgery

What does the study involve?
Participants enrolled into the study are invited for a research appointment alongside their Cataract Assessment appointment. A member of the research team accompanies participants throughout all the stages of their appointment and (with permission) audio-records the conversations participants have with the doctor and nurses on the day. This allows the researchers to go back and accurately record and analyse the content after the appointment.
During the appointment, participants are asked to complete a questionnaire about their knowledge and understanding of cataracts and cataract surgery, which results after surgery matter most to participants, and how ready participants feel to make a decision about cataract surgery. Participants are also asked to complete another questionnaire (the ‘Cat-PROM5’) which assesses how much they are affected by their cataract. Participants have a routine assessment with a nurse, and then see the doctor who discusses the potential for having cataract surgery. After an initial assessment of participant’s eyes and vision, they are randomly allocated to either continue with a routine assessment, or to have a few additional eye health checks alongside using the Cataract Decision Aid as part of their discussion with the doctor. About half of the participants have a routine assessment, the other half use the Cataract Decision Aid. Both sets of participants discuss the risks and benefits of cataract surgery, but only one set uses the Cataract Decision Aid as part of this discussion. Participants and the doctor then decide whether or not to add their name to the waiting list to have cataract surgery. After participants have finished their assessment with the doctor and nurses, they are asked to complete a second questionnaire about their knowledge and understanding of cataracts and cataract surgery, after which the appointment is complete. At a later date, a member of the research team contacts participants by post or phone to ask them to complete another ‘Cat-PROM5’ questionnaire and a ‘postal follow-up cover sheet’. This captures changes in participants vision and additional information about their recent spectacle use and spectacle prescription. For participants who did have cataract surgery, these questionnaires are sent 6-8 weeks after surgery has taken place. If, however, they did not have surgery, these questionnaires are sent 8-12 weeks after their Cataract Assessment with the doctor. The researchers are also working with researchers from Cardiff University and the University of Bristol who would also like to get in touch with participants to have a short informal interview about their experience of deciding whether or not to have surgery. This interview can take place over the telephone or in a place convenient to them. The interview should take between 30 minutes and one hour, but participants can stop the discussion at any point.

What are the possible benefits and risks of participating?
Participants receive the same high level of care as they would if they were not taking part in the study. Participants allocated to receive the Cataract Decision Aid during the consultation will be able to discuss individual levels of potential risk and benefit of cataract surgery, rather than receiving information in general terms only. The results from the study will show whether using a Cataract Decision Aid will help future patients and doctors make a better-informed decision about if and when to opt for surgery, with the ultimate goal to improve patient care. The study assessments may take a little longer than normal clinic appointments as more detailed information is gathered about participants and their health. Because of this, if participants have already been sent an appointment, this may need to be rescheduled to a new date. Participants are contacted to offer an alternative appointment – this will not affect their position on the surgery waiting list and will be as close to their original appointment date as possible. Any additional assessments and questionnaires which are completed as part of the research appointment carry no additional risk.

Where is the study run from?
This study is being led by University Hospitals Bristol NHS Foundation Trust. The study is recruiting participants from across three sites:
1. University Hospitals Bristol NHS Foundation Trust
2. Brighton & Sussex University Hospitals NHS Trust
3. Torbay and South Devon NHS Foundation Trust

When is the study starting and how long is it expected to run for?
June 2018 to June 2019

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

Who is the main contact?
Prof. John Sparrow

Contact information

Prof John Sparrow
Scientific

NIHR Cataract Research Programme
Queen Anne Building
Bristol Eye Hospital
Lower Maudlin Street
Bristol
BS1 2LX
United Kingdom

Study information

Primary study design	Interventional
Study design	Feasibility randomised controlled trial
Secondary study design	Randomised controlled trial
Study type	Participant information sheet
Scientific title	Involve-CAT: a feasibility randomised controlled trial of a cataract decision aid
Study acronym	Involve-CAT
Study objectives	Involve-CAT will explore the feasibility of establishing a future Randomised Controlled Trial (RCT) using the Cataract Decision Aid as an intervention. Embedded within the trial will be qualitative and cost elements and an exercise to validate the benefits prediction model developed earlier in the research programme.
Ethics approval(s)	North West – Liverpool East Research Ethics Committee, Barlow House, 3rd Floor, 4 Minshull Street, Manchester, M1 3DZ, Tel: +44 (0)207 104 8001, Email: nrescommittee.northwest-liverpooleast@nhs.net, 06/09/2018, IRAS project ID: 246649, REC ref: 18/NW/0476
Health condition(s) or problem(s) studied	Shared decision-making about cataract surgery
Intervention	Participants enrolled into the study will be invited for a research appointment alongside their Cataract Assessment appointment. A member of the research team will accompany participants throughout all the stages of their appointment and (with permission) will audio-record the conversations participants have with the Doctor and nurses on the day. This allows the researchers to go back and accurately record and analyse the content after the appointment. During the appointment, participants will be asked to complete a questionnaire about their knowledge and understanding of cataracts and cataract surgery, also which results after surgery matter most to participants, and how ready participants feel to make a decision about cataract surgery. Participants will also be asked to complete another questionnaire (the ‘Cat-PROM5’) which assesses how much they are affected by their cataract. Participants will have a routine assessment with a nurse, and then see the Doctor who will discuss the potential for having cataract surgery. After an initial assessment of participant’s eyes and vision, they will be randomly allocated to either continue with a routine assessment, or to have a few additional eye health checks alongside using the Cataract Decision Aid as part of their discussion with the Doctor. About half of the participants will have a routine assessment, the other half will use the Cataract Decision Aid. Both sets of participants will discuss the risks and benefits of cataract surgery, but only one set will use the Cataract Decision Aid as part of this discussion. Participants and the Doctor will then decide whether or not to add their name to the waiting list to have cataract surgery. After participants have finished their assessment with the Doctor and nurses, they will be asked to complete a second questionnaire about their knowledge and understanding of cataracts and cataract surgery, after which the appointment will be complete. At a later date, a member of the research team will contact participants by post or phone to ask them to complete another ‘Cat-PROM5’ questionnaire and a ‘postal follow up cover sheet’. This will be to capture changes in participants vision and additional information about their recent spectacle use and spectacle prescription. For participants who did have cataract surgery, these questionnaires will be sent to 6-8 weeks after surgery has taken place. If, however, they did not have surgery, these questionnaires will be sent to 8-12 weeks after their Cataract Assessment with the Doctor. The trialists are also working with researchers from Cardiff University and the University of Bristol who would also like to get in touch with participants to have a short informal interview about their experience of deciding whether or not to have surgery. This interview can take place over the telephone or, in a place convenient to them. The interview should take between 30 minutes and one hour, but participants can stop the discussion at any point.
Intervention type	Other
Primary outcome measure(s)	Patients’ knowledge about options, their preferences and readiness to make a decision, assessed using the Cataract Decision Quality Measure before and after pre-operative clinician consultation
Key secondary outcome measure(s)	The likely effectiveness and cost-effectiveness of the decision support tool and the need for a subsequent full-scale trial, assessed through analysis of the following themes: 1. Estimated sample size, and the most appropriate primary/secondary outcomes for a main trial assessed using the effect size 2. Recruitment and retention rates, comparing numbers of study completion, declines and screen failures against routine care volume over the recruitment period 3. Decision support costs estimated through analysis of the duration and staff costs of pre-operative assessment and data collection in the intervention arm compared to routine care arm 4. Potential cost savings from avoidance of high risk/low benefit surgery and avoiding costly complications and complication-induced visual disability 5. Quality and level of shared decision making assessed using the Observer OPTION5 instrument during pre-operative assessment 6. Patient and clinician experience of the use of decision support tools, assessed using qualitative interviews after the pre-operative assessment study visit 7. Acceptability of the decision aid to patients and clinicians, assessed using qualitative interviews after the pre-operative assessment study visit 8. Self-reported difficulty with vision, assessed using the Cat-PROM5 questionnaire pre- and post-operatively 9. Uptake of cataract surgical option following patient-clinician interaction when using CDA compared to routine care 10. Initial validation of the benefits prediction model developed earlier in the Programme for predicting self-reported Cat-PROM5 benefit from surgery, assessed pre and post-operatively
Completion date	10/06/2019

Eligibility

Participant type(s)	Mixed
Age group	Mixed
Sex	All
Target sample size at registration	40
Total final enrolment	49
Key inclusion criteria	Patients: Patients undergoing cataract surgery are eligible to be recruited to the study if they meet the following criteria: 1. Aged 50 years or over at time of recruitment 2. Referred for and subsequently deemed clinically eligible for either first or second eye cataract surgery 3. Ability to provide informed consent 4. Ability to read and understand study materials (PIS, Cat-PROM5, CDA, CDQM etc) 5. Willingness to participate Health Professionals: Health Professionals are eligible to be recruited to the study if they meet the following criteria: 1. Willingness to participate 2. Ability and willingness to use the Cataract Decision Aid to help patients make a decision about whether or not to have cataract surgery
Key exclusion criteria	Previous participation in earlier elements of the cataract research programme
Date of first enrolment	09/10/2018
Date of final enrolment	29/01/2019

Locations

Countries of recruitment

United Kingdom
England

Study participating centres

University Hospitals Bristol NHS Foundation Trust

NIHR Cataract Research Programme
Room QA2-007 Queen Anne Building
Bristol Eye Hospital, Lower Maudlin Street
Bristol
BS1 2LX
United Kingdom

Brighton & Sussex University Hospitals NHS Trust

Brighton & Sussex University Hospitals NHS Trust
Eastern Road
Brighton
BN2 5BE
United Kingdom

Torbay and South Devon NHS Foundation Trust

Torbay and South Devon NHS Foundation Trust
Torbay Hospital
Lawes Bridge
Torquay
TQ2 7AA
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Other
IPD sharing plan	Once the researchers have completed the study, including the analysis, the results will be published in accordance with academic due process. Participant level data will be archived in line with local policy.

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	A randomized controlled trial comparing femtosecond laser-assisted cataract surgery versus conventional phacoemulsification surgery	01/01/2019	20/08/2025	Yes	No
Results article	The Royal College of Ophthalmologists' National Ophthalmology Database Study of cataract surgery. Report 5: Clinical outcome and risk factors for posterior capsule rupture and visual acuity loss following cataract surgery in patients aged 90 years and older	01/07/2019	20/08/2025	Yes	No
Funder report results	version 1.3	31/03/2020	20/08/2025	No	No
HRA research summary			28/06/2023	No	No
Other publications	Cat-PROM5: a brief psychometrically robust self-report questionnaire instrument for cataract surgery	01/04/2018	20/08/2025	Yes	No
Other publications	Cataract surgery patient-reported outcome measures: a head-to-head comparison of the psychometric performance and patient acceptability of the Cat-PROM5 and Catquest-9SF self-report questionnaires	01/04/2018	20/08/2025	Yes	No
Participant information sheet	Participant information sheet	11/11/2025	11/11/2025	No	Yes
Protocol file	version 1.0	01/06/2018	20/08/2025	No	No

Additional files

ISRCTN11309852 WP4_Involve-CAT PROTOCOL_v1.0_01June2018.pdf: Protocol file
ISRCTN11309852 2020.03.31 Revised NIHR Programme Final Report V1.3 - Clean.pdf: Funder report results

Editorial Notes

20/08/2025: The following changes were made to the trial record:
1. Publication references added.
2. Uploaded protocol (not peer-reviewed) as an additional file.
3. A funder report was uploaded as an additional file.
21/08/2019: The following changes were made to the trial record:
1. The recruitment end date was changed from 24/06/2019 to 29/01/2019.
2. The overall trial record was changed from 24/06/2019 to 10/06/2019.
3. The intention to publish date was changed from 24/06/2020 to 24/09/2020.
4. The total final enrolment number was added.
17/05/2019: Internal review.