https://doi.org/10.4081/ecj.2026.15635
Methodological approaches to identify frequent emergency department users: a population-based study
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Accepted: 21 August 2026
Published: 5 October 2026
Frequent users (FUs) represent a small patient group accounting for a large share of Emergency Department (ED) visits. We compared a traditional calendar-year approach with a rolling 12-month approach for identifying FUs. We conducted a population-based observational study using regional ED records from the Veneto Region, Italy, between 2010 and 2023. FUs were defined as patients with ≥4 ED visits and identified using either a Traditional calendar-year Approach (TA) or a Rolling 12-month Approach (RA). Patients were classified as mild (4–5 visits), moderate (6–11), or high (≥12). Descriptive analyses and univariate logistic regressions were used to compare FUs with non-FUs. The RA identified substantially more FUs than the TA, with FUs accounting for 26.3% versus 16.8% of annual ED visits and 12.4% versus 5.0% of patients per year. Most FUs were mild (70.7%) or moderate (27.0%). Compared with non-FUs, FUs were older (50.2 vs. 44.7 years), were more likely to have co-payment exemptions (OR 1.52, 95%CI 1.51-1.53), to arrive via ambulance (OR 1.42, 95%CI 1.41-1.42), had higher triage priority (OR 1.21, 95%CI 1.21-1.21), and hospitalization risk (OR 1.34, 95% CI 1.33-1.34). Minor conditions were the leading cause of ED visits in both FUs (46.1%) and non-FUs (38.9%). The 12-month rolling approach identifies substantially more FUs compared to the traditional calendar-year approach. These findings highlight the importance of the method used to define FUs, as different yield significant differences in the estimates.
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CRediT authorship contribution
Laura Salmaso, conceptualization, investigation, Data curation, formal analysis, writing – original draft; Marta Zanovello, conceptualization, investigation, writing – original draft; Claudio Barbiellini Amidei, Ugo Fedeli, data curation, writing – review and editing; Mario Saia, data curation, methodology, writing – review and editing.
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Data Availability Statement
The data that support the findings of this study are not publicly available. Aggregated data can be accessed by contacting to the corresponding author upon reasonable request.
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