Author’s Disclosure Block: Matthaeus Ware: none; Marko Popovic: Grants: Fighting Blindness Canada, DSI Institute, University of Toronto, PSI Foundation; Brian Ballios: Advisory Boards and Consultancy: Bayer, Apellis, F. Hoffmann-La Roche, GelMEDIX, Novartis, Biocon, Endogena Therapeutics - Funded Grants: Foundation Fighting Blindness U.S., Usher1F Collaborative Canada, Ganz Family Foundation, CIHR, CFI 

Abstract Body 

Purpose: The goal of this study was to understand the patterns of appointment non-adherence (cancellations, no-shows, and rescheduling) across various ophthalmology care settings, including emergency, comprehensive, and subspecialty clinics. Particularly within the strained Canadian healthcare system, it is important for ophthalmology clinics to function as efficiently as possible. When a patient cancels their appointment, it creates the potential for that time to go unused. Similarly, when a patient reschedules or is a no-show, not only will that slot potentially not be filled, but theymay try and re-book for a later time, thus adding to the backlog of patients waiting to be seen. Identifying the factors that influence appointment non-adherence will inform the development of more efficient ophthalmology practices. Study Design:  Retrospective chart review of cross-sectional data. Methods: Anonymized patient appointment data was collected from the OSCAR Pro electronic medical record system at the Kensington Eye Institute (KEI), University of Toronto. Appointment data from between Feb 2013–Sep 2024 was included for all patients who were between 5–90 years old on the date of their scheduled appointment at any of KEI’s emergency, comprehensive, and subspecialty clinics. This large database of 786,463appointments was then collated, stratified, and analyzed using Python coding language. Research ethics board approval was obtained from the University of Toronto prior to data collection and adhered to throughout the study. Results: Male patients had a higher no-show rate than female patients (5.34% versus 4.25%). Monday had the most no-shows compared to otherweekdays (5.49% versus 4.51%). Appointments booked between 4–6PM had the lowest no-show rate (1.04%) compared to all earlier time slots (4.75%) and the most cancellations (35.70% versus 26.50%). Patients ≤ 30 years old had over two times the rate of noshows than patients > 30 years old (9.41% versus 4.42%). Additional factors were identified to affect non-adherence rates, including distance between home and KEI, type of clinic (i.e. emergency, comprehensive, subspecialty), medical reason for visit, and number of visits and practitioners seen prior to non-adherence. Conclusions: In the first study of its kind, spanning over 780,000 appointments across a decade, we have identified key factors that influence patient non-adherence to their scheduled visits at emergency, comprehensive, and subspecialty ophthalmology clinics. Our findings provide insight into initiatives/changes that could be implemented to decrease the likelihood of appointment nonadherence and optimize the scheduling efficiency of ophthalmology clinics, thus benefiting both the ophthalmic healthcare teams and their future patients.