# Impact of a community-based asynchronous review clinic on appointment attendance delays across an eye hospital network in London, UK: an interrupted time series analysis

## TL;DR

A new community-based eye clinic in London reduced appointment delays for patients with chronic eye conditions, especially after the initial backlog from the pandemic was cleared.

## Contribution

Demonstrates the effectiveness of asynchronous review clinics in reducing appointment delays for chronic eye disease monitoring.

## Key findings

- Opening the clinic reduced average attendance delays by 8.1 days per week shortly after launch.
- Delays continued to decrease at a slower rate of 0.3 days per week after the initial backlog was cleared.
- No significant differences in delay reduction were found by age, gender, or deprivation level.

## Abstract

To assess the impact of opening a large community-based asynchronous review ophthalmic clinic on attendance delays among patients with stable chronic eye disease attending a London teaching eye hospital network.

Interrupted time-series analysis of routine electronic health records of appointment attendances.

A large eye hospital network with facilities across London, UK, between June 2018 and April 2023.

We analysed 69 257 attendances from 39 357 patients, with glaucoma and medical retina accounting for 62% (n=42 982) and 38% (n=26 275) of visits, respectively. Patients over 65 made up 54% (n=37 824) of attendances, while 53% (n=37 014) were from the more deprived half of the population, and 51% (n=35 048) were males.

An asynchronous review clinic opened in a shopping centre in London, in autumn 2021, following the COVID-19 lockdown in spring 2020.

Average attendance delays (days), calculated as the difference between follow-up attendance date and the latest clinically appropriate date determined at the preceding attendance.

Pre-COVID-19, attendance delays for chronic eye disease monitoring were increasing by 0.9 days per week (95% CI, 0.8 to 0.9) on average, worsening to 2.0 days per week (95% CI, 2.0 to 2.0) after the first COVID-19 national lockdown, mid-March 2020. Opening the asynchronous review clinic increased appointment capacity, with delays decreasing on average by 8.1 days per week (95% CI, 8.1 to 8.2) shortly after opening. The rate of decrease slowed to 0.3 days per week (95% CI, 0.3 to 0.3) after 5 months. We found no significant differences in average attendance delays by age, gender or level of deprivation.

The asynchronous review clinic significantly reduced attendance delays across the hospital network, addressing pre-existing backlog for stable chronic eye diseases. The reduction appeared to be maintained after the initial backlog had been cleared.