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

Broadbent, Deborah M.; Wang, Amu; Cheyne, Christopher P.; James, Marilyn; Lathe, James; Stratton, Irene M.; Roberts, John; Moitt, Tracy; Vora, Jiten P.; Gabbay, Mark; Garc�a-Fi�ana, Marta; Harding, Simon P.

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


Authors

Deborah M. Broadbent

Amu Wang

Christopher P. Cheyne

MARILYN JAMES MARILYN.JAMES@NOTTINGHAM.AC.UK
Professor of Health Economics

James Lathe

Irene M. Stratton

John Roberts

Tracy Moitt

Jiten P. Vora

Mark Gabbay

Marta Garc�a-Fi�ana

Simon P. Harding



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 2year follow-up) in individuals with diabetes aged 12years or older registered with a single English screening programme. Participants were randomly allocated 1:1 at baseline to individualised screening at 6, 12 or 24months 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 2year 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 2year 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. [Figure not available: see fulltext.]

Citation

Broadbent, D. M., Wang, A., Cheyne, C. P., James, M., Lathe, J., Stratton, I. M., …Harding, S. P. (2021). Safety and cost-effectiveness of individualised screening for diabetic retinopathy: the ISDR open-label, equivalence RCT. Diabetologia, 64(1), 56-69. https://doi.org/10.1007/s00125-020-05313-2

Journal Article Type Article
Acceptance Date Sep 8, 2020
Online Publication Date Nov 4, 2020
Publication Date Jan 1, 2021
Deposit Date Jan 14, 2021
Publicly Available Date Mar 29, 2024
Journal Diabetologia
Print ISSN 0012-186X
Electronic ISSN 1432-0428
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 64
Issue 1
Pages 56-69
DOI https://doi.org/10.1007/s00125-020-05313-2
Keywords Internal Medicine; Endocrinology, Diabetes and Metabolism
Public URL https://nottingham-repository.worktribe.com/output/5021652
Publisher URL https://link.springer.com/article/10.1007/s00125-020-05313-2
Additional Information The authors and the ISDR Study Group.