Frequent callers and users of ambulance services: An international scoping review using Andersen's Behavioural Model...

Frequent callers and users of ambulance services represent a small but complex patient cohort who account for a disproportionate number of emergency medical service contacts. Although frequent use has been examined in emergency department settings, less is known about frequent use in the out-of-hospital ambulance context. Inconsistent terminology and definitions further limit comparison across studies and make it difficult to develop evidence-informed responses.

This scoping review aimed to map the international literature on frequent callers and users of ambulance services, identify how frequent use has been defined, and examine reported factors associated with frequent ambulance use using Andersen's Behavioural Model of Health Service Use.

A scoping review was conducted using Joanna Briggs Institute methodology and reported in accordance with the PRISMA-ScR checklist. Five databases were searched on 17 September 2025: CINAHL, Medline, Emcare, PsycINFO and Scopus. Google Scholar and reference lists of included studies and relevant reviews were also searched. Peer-reviewed English-language studies were eligible if they examined frequent callers or users in the out-of-hospital ambulance context. Data were charted and synthesised descriptively, with reported factors mapped to Andersen's predisposing, enabling, need and health behaviour domains.

Forty-one studies from 12 countries were included. Four main terms were used across the literature: frequent caller, frequent user, repeat caller/user and frequent presenter. Twenty different definitions of frequent use were identified, ranging from two or more ambulance contacts in 12 months to 10 or more contacts per month. Most studies reported predisposing factors, particularly age and gender, while enabling factors such as transport access, socioeconomic status, insurance, accessibility and system navigation were less commonly examined. Need factors commonly included chronic medical conditions, mental health concerns, comorbidities and reduced quality of life. Health behaviours included alcohol and other drug use, out-of-hours ambulance use, GP use, patient-provider relationships and calling as a last resort.

The ambulance frequent-use literature is heterogeneous and largely descriptive. A consistent definition and reporting framework are needed to support comparison across studies, deepen understanding of the factors driving frequent ambulance use, and inform person-centred interventions for this vulnerable cohort.