scholarly journals Individualised variable-interval risk-based screening for sight-threatening diabetic retinopathy: the Liverpool Risk Calculation Engine

Diabetologia ◽  
2017 ◽  
Vol 60 (11) ◽  
pp. 2174-2182 ◽  
Author(s):  
Antonio Eleuteri ◽  
◽  
Anthony C. Fisher ◽  
Deborah M. Broadbent ◽  
Marta García-Fiñana ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Variable Interval ◽  
Risk Calculation

OP60 Optimising Risk-Based Screening: The Case Of Diabetic Eye Disease

2018 ◽  
Vol 34 (S1) ◽  
pp. 21-21
Author(s):  
Christopher Sampson ◽  
Marilyn James ◽  
David Whynes ◽  
Antonio Eleuteri ◽  
Simon Harding
Keyword(s):  
Diabetic Retinopathy ◽  
Cost Effectiveness ◽  
Screening Program ◽  
Cost Effective ◽  
Eye Disease ◽  
Risk Calculation ◽  
Diabetic Eye Disease ◽  
The Uk ◽  
The Cost ◽  
Level Of Risk

Introduction:There is growing evidence that many people attending annual screening for diabetic retinopathy in the United Kingdom (UK) are at low risk of developing the disease. This has led to new policy statements. However, the basis on which to establish a risk-based individualized variable-recall screening program has not yet been determined. We present a methodology for using information on an individual's risk factors to improve the allocation of resources within a screening program.Methods:We developed a patient-level state-transition model to evaluate the cost-effectiveness of risk-based screening for diabetic retinopathy in the UK. The model incorporated a recently developed risk calculation engine that predicts an individual's risk of disease onset, and allocated individuals to alternative screening recall periods according to this level of risk. Using the findings, we demonstrate a means of estimating: (i) a threshold level of risk, above which individuals should be invited to screening, and (ii) the optimum screening recall period for an individual, based on the expected cost-effectiveness of screening and treatment.Results:The cost-effectiveness analysis demonstrated that standardized screening (current practice) is the least cost-effective program. Individualized screening can improve outcomes at a reduced cost. We found it feasible – though computationally expensive – to incorporate a risk calculation engine into a decision model in Microsoft Excel. In an optimized screening program, the majority or patients would be invited to attend screening at least two years after a negative screening result.Conclusions:Individualized risk-based screening is likely to be cost-effective in the context of diabetic eye disease in the UK. It is expected that risk calculation engines will be developed in other disease areas in the future, and used to allocate screening and treatment at the individual level. It is important that researchers develop robust methods for combining risk calculation engines into decision analytic models and health technology assessment more broadly.

scholarly journals Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation

2020 ◽  
Author(s):  
Paula Byrne ◽  
Clare Thetford ◽  
Mark Gabbay ◽  
Pam Clarke ◽  
Emily Doncaster ◽  
...  
Keyword(s):  
Health Care ◽  
Diabetic Retinopathy ◽  
Health Care Professionals ◽  
Controlled Trial ◽  
Comparative Method ◽  
Variable Interval ◽  
Incidence Rates ◽  
Successful Implementation ◽  
Eye Screening ◽  
Screening Intervals

Abstract Background Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals. Methods We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semi-structured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCPs from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening. Results Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWDs, referral into screening of PWDs with diabetic changes regardless of planned interval. For PWDs the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCPs and PWDs that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWDs, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system. Conclusions Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

scholarly journals Individualised screening for diabetic retinopathy: the ISDR study—rationale, design and methodology for a randomised controlled trial comparing annual and individualised risk-based variable-interval screening

BMJ Open ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. e025788 ◽  
Author(s):  
Deborah M Broadbent ◽  
Christopher J Sampson ◽  
Amu Wang ◽  
Lola Howard ◽  
Abigail E Williams ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Cost Effectiveness ◽  
Randomised Controlled Trial ◽  
Screening Programme ◽  
Controlled Trial ◽  
Randomised Trial ◽  
Variable Interval ◽  
Randomised Controlled ◽  
The Uk

IntroductionCurrently, all people with diabetes (PWD) aged 12 years and over in the UK are invited for screening for diabetic retinopathy (DR) annually. Resources are not increasing despite a 5% increase in the numbers of PWD nationwide each year. We describe the rationale, design and methodology for a randomised controlled trial (RCT) evaluating the safety, acceptability and cost-effectiveness of personalised variable-interval risk-based screening for DR. This is the first randomised trial of personalised screening for DR and the largest ophthalmic RCT in the UK.Methods and analysisPWD attending seven screening clinics in the Liverpool Diabetic Eye Screening Programme were recruited into a single site RCT with a 1:1 allocation to individualised risk-based variable-interval or annual screening intervals. A risk calculation engine developed for the trial estimates the probability that an individual will develop referable disease (screen positive DR) within the next 6, 12 or 24 months using demographic, retinopathy and systemic risk factor data from primary care and screening programme records. Dynamic, secure, real-time data connections have been developed. The primary outcome is attendance for follow-up screening. We will test for equivalence in attendance rates between the two arms. Secondary outcomes are rates and severity of DR, visual outcomes, cost-effectiveness and health-related quality of life. The required sample size was 4460 PWD. Recruitment is complete, and the trial is in follow-up.Ethics and disseminationEthical approval was obtained from National Research Ethics Service Committee North West – Preston, reference 14/NW/0034. Results will be presented at international meetings and published in peer-reviewed journals. This pragmatic RCT will inform screening policy in the UK and elsewhere.Trial registration numberISRCTN87561257; Pre-results.

scholarly journals Safety and cost-effectiveness of individualised screening for diabetic retinopathy: the ISDR open-label, equivalence RCT

Diabetologia ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 56-69 ◽  
Author(s):  
Deborah M. Broadbent ◽  
◽  
Amu Wang ◽  
Christopher P. Cheyne ◽  
Marilyn James ◽  
...  
Keyword(s):  
Diabetic Retinopathy ◽  
Cost Effectiveness ◽  
National Health Service ◽  
Time Horizon ◽  
Screening Programme ◽  
Variable Interval ◽  
Diabetic Retinopathy Screening ◽  
Screening Intervals ◽  
Retinopathy Screening

Abstract Aims/hypothesis Using variable diabetic retinopathy screening intervals, informed by personal risk levels, offers improved engagement of people with diabetes and reallocation of resources to high-risk groups, while addressing the increasing prevalence of diabetes. However, safety data on extending screening intervals are minimal. The aim of this study was to evaluate the safety and cost-effectiveness of individualised, variable-interval, risk-based population screening compared with usual care, with wide-ranging input from individuals with diabetes. Methods This was a two-arm, parallel-assignment, equivalence RCT (minimum 2 year follow-up) in individuals with diabetes aged 12 years or older registered with a single English screening programme. Participants were randomly allocated 1:1 at baseline to individualised screening at 6, 12 or 24 months for those at high, medium and low risk, respectively, as determined at each screening episode by a risk-calculation engine using local demographic, screening and clinical data, or to annual screening (control group). Screening staff and investigators were observer-masked to allocation and interval. Data were collected within the screening programme. The primary outcome was attendance (safety). A secondary safety outcome was the development of sight-threatening diabetic retinopathy. Cost-effectiveness was evaluated within a 2 year time horizon from National Health Service and societal perspectives. Results A total of 4534 participants were randomised. After withdrawals, there were 2097 participants in the individualised screening arm and 2224 in the control arm. Attendance rates at first follow-up were equivalent between the two arms (individualised screening 83.6%; control arm 84.7%; difference −1.0 [95% CI −3.2, 1.2]), while sight-threatening diabetic retinopathy detection rates were non-inferior in the individualised screening arm (individualised screening 1.4%, control arm 1.7%; difference −0.3 [95% CI −1.1, 0.5]). Sensitivity analyses confirmed these findings. No important adverse events were observed. Mean differences in complete case quality-adjusted life-years (EuroQol Five-Dimension Questionnaire, Health Utilities Index Mark 3) did not significantly differ from zero; multiple imputation supported the dominance of individualised screening. Incremental cost savings per person with individualised screening were £17.34 (95% CI 17.02, 17.67) from the National Health Service perspective and £23.11 (95% CI 22.73, 23.53) from the societal perspective, representing a 21% reduction in overall programme costs. Overall, 43.2% fewer screening appointments were required in the individualised arm. Conclusions/interpretation Stakeholders involved in diabetes care can be reassured by this study, which is the largest ophthalmic RCT in diabetic retinopathy screening to date, that extended and individualised, variable-interval, risk-based screening is feasible and can be safely and cost-effectively introduced in established systematic programmes. Because of the 2 year time horizon of the trial and the long time frame of the disease, robust monitoring of attendance and retinopathy rates should be included in any future implementation. Trial registration ISRCTN 87561257 Funding The study was funded by the UK National Institute for Health Research.

scholarly journals Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation

2020 ◽  
Author(s):  
Paula Byrne ◽  
Clare Thetford ◽  
Mark Gabbay ◽  
Pam Clarke ◽  
Emily Doncaster ◽  
...  
Keyword(s):  
Health Care ◽  
Diabetic Retinopathy ◽  
Health Care Professionals ◽  
Controlled Trial ◽  
Comparative Method ◽  
Variable Interval ◽  
Incidence Rates ◽  
Successful Implementation ◽  
Eye Screening ◽  
Screening Intervals

Abstract Background Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals. Methods We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semi-structured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCPs from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening. Results Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWDs, referral into screening of PWDs with diabetic changes regardless of planned interval. For PWDs the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCPs and PWDs that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWDs, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system. Conclusions Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

scholarly journals Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation

2020 ◽  
Author(s):  
Paula Byrne ◽  
Clare Thetford ◽  
Mark Gabbay ◽  
Pam Clarke ◽  
Emily Doncaster ◽  
...  
Keyword(s):  
Health Care ◽  
Diabetic Retinopathy ◽  
Health Care Professionals ◽  
Controlled Trial ◽  
Comparative Method ◽  
Variable Interval ◽  
Incidence Rates ◽  
Successful Implementation ◽  
Eye Screening ◽  
Screening Intervals

Abstract Background: Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals. Methods: We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semi-structured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCPs from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening. Results: Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWDs, referral into screening of PWDs with diabetic changes regardless of planned interval. For PWDs the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCPs and PWDs that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWDs, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system. Conclusions: Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

scholarly journals Personalising screening of sight-threatening diabetic retinopathy - qualitative evidence to inform effective implementation

2020 ◽  
Author(s):  
Paula Byrne ◽  
Clare Thetford ◽  
Mark Gabbay ◽  
Pam Clarke ◽  
Emily Doncaster ◽  
...  
Keyword(s):  
Health Care ◽  
Diabetic Retinopathy ◽  
Health Care Professionals ◽  
Controlled Trial ◽  
Comparative Method ◽  
Variable Interval ◽  
Incidence Rates ◽  
Successful Implementation ◽  
Eye Screening ◽  
Screening Intervals

Abstract Background Internationally, systematic screening for sight-threatening diabetic retinopathy (STDR) usually includes annual recall. Researchers and policy-makers support extending screening intervals, citing evidence from observational studies with low incidence rates. However, there is little research around the acceptability to people with diabetes (PWD) and health care professionals (HCP) about changing eye screening intervals. Methods We conducted a qualitative study to explore issues surrounding acceptability and the barriers and enablers for changing from annual screening, using in-depth, semi-structured interviews analysed using the constant comparative method. PWD were recruited from general practices and HCPs from eye screening networks and related specialties in North West England using purposive sampling. Interviews were conducted prior to the commencement of and during a randomised controlled trial (RCT) comparing fixed annual with variable (6, 12 or 24 month) interval risk-based screening. Results Thirty PWD and 21 HCP participants were interviewed prior to and 30 PWD during the parallel RCT. The data suggests that a move to variable screening intervals was generally acceptable in principle, though highlighted significant concerns and challenges to successful implementation. The current annual interval was recognised as unsustainable against a backdrop of increasing diabetes prevalence. There were important caveats attached to acceptability and a need for clear safeguards around: the safety and reliability of calculating screening intervals, capturing all PWDs, referral into screening of PWDs with diabetic changes regardless of planned interval. For PWDs the 6-month interval was perceived positively as medical reassurance, and the 12-month seen as usual treatment. Concerns were expressed by many HCPs and PWDs that a 2-year interval was too lengthy and was risky for detecting STDR. There were also concerns about a negative effect upon PWD care and increasing non-attendance rates. Amongst PWDs, there was considerable conflation and misunderstanding about different eye-related appointments within the health care system. Conclusions Implementing variable-interval screening into clinical practice is generally acceptable to PWD and HCP with important caveats, and misconceptions must be addressed. Clear safeguards against increasing non-attendance, loss of diabetes control and alternative referral pathways are required. For risk calculation systems to be safe, reliable monitoring and clear communication is required.

The Effects of Variable-Interval and Fixed-Interval Signal Presentation Schedules on the Auditory Evoked Response

1969 ◽  
Vol 12 (1) ◽  
pp. 199-209 ◽  
Author(s):  
David A. Nelson ◽  
Frank M. Lassman ◽  
Richard L. Hoel
Keyword(s):  
Variable Interval ◽  
Tone Burst ◽  
Signal Amplitude ◽  
Fixed Interval ◽  
Interval Schedule ◽  
Sensation Level ◽  
Fixed Interval Schedule ◽  
Auditory Evoked Responses ◽  
Auditory Evoked Response ◽  
Signal Presentation

Averaged auditory evoked responses to 1000-Hz 20-msec tone bursts were obtained from normal-hearing adults under two different intersignal interval schedules: (1) a fixed-interval schedule with 2-sec intersignal intervals, and (2) a variable-interval schedule of intersignal intervals ranging randomly from 1.0 sec to 4.5 sec with a mean of 2 sec. Peak-to-peak amplitudes (N 1 — P 2 ) as well as latencies of components P 1 , N 1 , P 2 , and N 2 were compared under the two different conditions of intersignal interval. No consistent or significant differences between variable- and fixed-interval schedules were found in the averaged responses to signals of either 20 dB SL or 50 dB SL. Neither were there significant schedule differences when 35 or 70 epochs were averaged per response. There were, however, significant effects due to signal amplitude and to the number of epochs averaged per response. Response amplitude increased and response latency decreased with sensation level of the tone burst.

Diabetic Retinopathy Improved With Candesartan

2008 ◽  
Vol 41 (20) ◽  
pp. 18
Author(s):  
SARA FREEMAN
Keyword(s):  
Diabetic Retinopathy
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