Reducing the Ambulance Call Volume with a Multi-Interventional Approach: A Prospective Observational Cohort Study

Background The medically unnecessary use of ambulance services imposes a significant functional and financial burden on the emergency health care system. The aim of this study was to evaluate the effectiveness of a group of interventions aimed at controlling the ambulance call volume. Methods This was a prospective, observational cohort study covering all ambulance dispatches in 2021–2024 in Helsinki, Finland. The interventions included updated guidelines for ambulance dispatching, permission for dispatchers to refer callers to alternative services and updated guidelines for urgent care telephone services and nursing homes. The main outcome measures were the number of ambulance calls and dispatched units. Results The number of ambulance calls (total number of units dispatched) decreased from 74 925 (87 695) in 2021 to 73 408 (85 695) in 2022, 73 394 (84 170) in 2023 and 65 334 (73 525) in 2024. When the mean annual number of ambulance calls from 2021–2023 was compared with the number of calls in 2024 the reduction was 11.6% (95% CI 11.4% − 11.8%), p < 0.001. The corresponding reduction in the mean annual number of unit dispatches was 14.2% (95% CI 14.0%-14.5%), p < 0.001. A reduction in the number of ambulance calls was observed in triage categories A, B and D, but not in C. Conclusions Several multi-agency interventions halted the long-term rising trend in ambulance case volume, leading to a reduction in both the number of calls and the number of dispatched units. Both overtriage in high-priority calls and the frequency of blue-light and siren responses decreased. Changes in the guidelines and performance of the emergency response centre most likely played a key role in all the interventions.