# Frequent users of the ambulance service in a Swedish region: a retrospective cohort study

## TL;DR

The study identifies frequent ambulance users in Sweden, showing they are older and often require emergency care, with high-frequency users having distinct needs.

## Contribution

The study introduces a classification of frequent ambulance users into moderate and high-frequency groups, revealing distinct characteristics and care needs.

## Key findings

- Frequent users account for 29% of ambulance missions despite being 8.4% of all users.
- High-frequency users are more likely to involve psychiatric emergencies and intoxications.
- Frequent users are older and more often transported to emergency departments.

## Abstract

This study aimed to describe the characteristics of frequent users of ambulance services and their corresponding ambulance missions.

A retrospective cohort study using register data from a Swedish region (approximately 308,000 inhabitants) was conducted. The dataset covered ambulance missions dispatched between 2019 and 2023; data from 2020–2022 were analyzed, with the extended timeframe (2019–2023) used to identify frequent users. Frequent users were defined as patients with four or more ambulance missions within a 365-day period, divided into moderate (patients with 4–11 missions within 365 days) and high-frequency users (≥ 12 missions within 365 days). Missions associated with these users were referred to as frequent, moderate-frequent, high-frequency, or non-frequent ambulance missions.

Between 2020 and 2022, 73,461 ambulance missions were utilized by 41,407 unique patients. Of these 41,407 patients, 8.4% were frequent users (7.9% moderate and 0.5% high-frequency users), but accounted for 29.0% of all ambulance missions. The remaining 91.6% were non-frequent users, accounting for 71.0% of the ambulance missions. Frequent users were older than non-frequent users (median age 75 vs 62, p < .001). Frequent ambulance missions were more often dispatched for dyspnoea (17.8% vs 11.6%, p < .001), convulsions (4.2% vs 2.1%, p < .001), and abdominal pain (10.5% vs 8.7%, p < .001) compared with non-frequent ambulance missions. Frequent ambulance missions were also more likely to be assigned to a higher triage level, and 77.7% resulted in transport to the emergency department. Compare to moderate-frequent ambulance missions, high-frequency missions were more often dispatched for psychiatric emergencies (6.2% vs 2.1%, p < .001) and intoxications (5.3% vs 2.0%, p < .001), and more frequently resulted in transport to psychiatric emergency care (3.6% vs 1.4%, p < .001), or not being conveyed (24.0% vs 16.1%, p < .001).

Frequent ambulance users account for a large proportion of all ambulance missions. The results indicate that frequent users are often in need of emergency care, and understanding this population’s needs is essential to ensure appropriate care. However, the group is heterogeneous and can be divided into frequent and high-frequency users, which have different characteristics. We suggest that future research investigates system-level approaches to identify frequent ambulance users and implement care plans to address patients’ needs and reduce ambulance utilisation.