Title: The effectiveness of Community vs. Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration (nAMD) with quiescent disease: a virtual trial. (The ECHoES trial)
Funder: Health and Social Care Research and Development Division (HSC R&D) of Public Health Agency, Northern Ireland

Abstract: DESIGN: ECHoES is a virtual trial of ophthalmologists’ and optometrists’ decisions about the need for anti-VEGF retreatment in patients with nAMD. It will be based on vignettes consisting of colour fundus and optical coherence tomography (OCT) images with accompanying clinical data. Vignettes will be created using information collected in a national comparative effectiveness trial of anti-VEGF drugs (the IVAN study) to mimic the characteristics of patients judged to be eligible for follow up in the community. Both groups will assess the same vignettes viewing images and data and submitting their decisions via the internet.SETTING: Ophthalmologists’ decisions will represent the Hospital Eye Service (HES). Optometrists’ decisions will represent the community / primary care setting.TARGET POPULATION: ECHoES aims to inform the provision of anti-VEGF services for patients with nAMD. Participants will be volunteers drawn from among HES ophthalmologists (either senior trainees or consultants) and community ‘high street’ optometrists.HEALTH TECHNOLOGIES BEING ASSESSED: Expertise of community optometrists (‘intervention’ group) and ophthalmologists (‘comparator’ group) in assessing the need for anti-VEGF retreatment in vignettes. The IVAN database will be interrogated to extract image sets made up of (a) fundus colour images and an OCT classified by the independent Network of Ophthalmic Reading Centres (NetwORC) as fluid free and (b) a subsequent OCT classified by the NetwORC as fluid free or fluid present (1:1 ratio) the latter requiring retreatment. Image pairs will cover a range of clinical presentations. Clinical factors (e.g. age gender smoking history visual acuity at time of first image time since macula fluid free visual acuity at time of second image) will vary in a representative manner. Participants’ decisions will be compared to ‘reference’ classifications (need for retreatment based on grading by the NetwORC and medical retina experts).MEASUREMENT OF COSTS AND OUTCOMES: The primary outcome (‘correct’ / ‘wrong’) is the participant’s decision about the need for retreatment (refer to hospital vs. suspicious or inactive categories) compared to the reference classification. Secondary outcomes are similar comparisons about the presence or absence of lesion components i.e. blood exudates sub-retinal fluid intra-retinal fluid/cysts pigment epithelial detachment. The primary outcome for the economic evaluation will be the cost per accurate retreatment decision.SAMPLE SIZE: Ophthalmologists and optometrists (each group n=48) will each assess 48 vignettes randomly sampled from the database (total 1152 vignettes). Each vignette will be assessed by two ophthalmologists and two optometrists. This sample size will have at least 90% power to test the hypothesis (with 2.5% 1-sided statistical significance) that the proportion of vignettes correctly identified as “refer for retreatment” by the optometrist group differs by no more than 10%. TIMETABLE: Months 1-4: Create vignette database. Months 2-8: develop web application for presentation of training and final sets of vignettes. Months 4-6: recruit ophthalmologists and optometrists. Months 7-8: train participants. Months 9-12: participants judge vignettes. Months 13-18: analyses and write-up of the results.PROTECTION AGAINST BIAS: Participants (optometrists and ophthalmologists) will be blind to the reference standard classifications. The order of assessment of vignettes by optometrists and ophthalmologists will be randomised. ANALYSES: Conditional logistic regression of correct decisions by ophthalmologists and optometrists compared to reference standard classifications; other analyses will investigate whether clinical factors influence decisions.


Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: EYE