Treatment decisions of UK hospital optometrists and ophthalmologists in patients with nAMD: a vignette study

Abstract

Purpose A vignette study to examine treatment decisions made by UK hospital optometrists in patients with neovascular age‐related macular degeneration (nAMD) and the effect of optometrists’ experience on agreement. Methods Patients with nAMD attending Manchester Royal Eye Hospital, Manchester, UK were identified as potential candidates for the case series of vignettes. The cases were chosen to reflect a varied case‐mix with respect to difficulty as well as ensuring good quality of the images. Each vignette included a history summary consisting of the number of previous injections given and visual acuity measurements at baseline, the previous visit, and the current visit. Images were compiled to show baseline fundus photographs and ocular coherence tomography (OCT) images with the current visit images on which the treatment decision was to be made along with the images from the previous visit. Hospital optometrists were recruited and asked to complete the series of vignettes, deciding if treatment was required at that visit and how confident they felt with that decision. Their responses were compared to the reference standard created by a consensus of consultant ophthalmologists with a sub‐speciality interest in medical retina. Results Regarding treatment decision for optometrists, the percentage correct value was 75% with the sensitivity being 75.6% (95% CI 70.1–80.3) and the specificity as 75.1% (95% CI 72.1–77.8). No statistically significant difference was found between differing levels of experience. However, there was a significant difference in confidence levels between groups. Potentially sight threatening decisions accounted for 6.4% of the optometrists’ decisions, 3.5% were made with a high confidence rating suggesting no discussion with an ophthalmologist was required. Conclusions Although the optometrists showed modest agreement with the reference standard in a series of cases that have higher than average complexity, the optometrists showed a similar amount of variability within their treatment decisions compared to the reference standard. The optometrists were therefore not inferior in their performance compared to the ophthalmologists and this can be seen as supporting evidence for their extended role within this clinical area. Experience did not have an effect on ‘correct’ treatment decisions although there was a statistically significant effect on increasing confidence of treatment decision.

Design and use of vignettes to investigate referral decision-making by optometrists

“…7 Studies using vignettes are starting to provide comparative data on diagnostic clinical decisions; e.g. between optometrists and ophthalmologists using images of wet age-related macular degeneration lesions 12 , 13 and measuring the impact of optical coherence tomography in primary care. 14 , 15 In this study, vignettes had the advantage of being a cost-effective way of assessing clinical practice across a variety of settings.…”