Improving endoscopy attendance rates in high-risk patient groups that are identified using a machine learning model

Aims To determine if a pre-appointment phone call, targeted at endoscopy patients, who based on a machine learning model, are predicted to be at higher likelihood of not attending, will reduce overall non-attendance rates and reduce inequalities in the non-attendance rate.

Methods This is a single-trust pilot project taking place between October 2024 and January 2025 that has been running for 35 days. 427 calls have been made, to 264 patients, ahead of 290 endoscopy appointments, mostly gastroscopies, flexi-sigmoidoscopies and colonoscopies. Each appointment was given an estimated DNA (did not attend) probability using a machine learning model trained on two years of prior endoscopy appointments across the trust. Factors contributing either positively or negatively to this probability include, but are not limited to: prior attendance history, demographic factors and procedure type. Most patients were called during working hours on weekdays, on average 4 days before their procedure. Calls were targeted at appointments with a 10% or greater probability of non-attendance – our ‘higher risk’ group. All calls were made by one person, using a PowerBI report built to collate and visualise all the information they needed to make the calls.

Results So far, patients have been successfully contacted by telephone in 231 of 290 appointments (80%). At time of writing, 211 of 231 appointments have passed their scheduled date. The non-attendance rate for 166 ‘higher risk’ appointments with a successful contact was 4.9%, rising to 12.6% when including ‘higher risk’ appointments with no successful contact. The average non-attendance rate for ‘higher risk’ appointments in the four months prior to this project was 24.4%, based on 580 attendances and 189 non-attendances. In the 216 high-risk appointments due a phone call, our model estimated a total of 45 non-attendances, compared to 20 observed. 14 of these 20 were appointments had no successful contact. 139 ‘higher risk’ appointments resulted in an attendance. The non-attendance rate for 61 appointments for patients living in the 20% most deprived areas, was 7.1% for appointments with a successful contact, rising to 11.3% when including those not successfully contacted. The pre-intervention average for such patients was 14.3%. A chi-square test comparing the number of attendances and non-attendances in ‘higher risk’ patients between the intervention period, and the four months prior, shows a statistically significant reduction in the proportion of appointments not attended (p=0.0010).

Conclusions Pre-appointment phone calls targeted at patients with a higher estimated probability of non-attendance are associated with a statistically significant reduction in the proportion of appointments not attended.

Publication History

Article published online:
27 March 2025