Frequent Callers to Emergency Medical Services: an observational cohort study from Region Zealand, Denmark (2018–2025)

Abstract

Frequent callers to Emergency Medical Services represent a small group of citizens who account for a substantial number of calls. Despite their impact, little is known about their characteristics and patterns of EMS use. This study aimed to examine frequency, dispatch outcomes, and characteristics of frequent callers in a prehospital setting. We conducted an observational cohort study of calls to the Emergency Medical Dispatch Center in Region Zealand, Denmark, between 2018 and 2025. Calls without a civil register number and individuals younger than 18 years were excluded. Frequent callers were defined as individuals contacting 1-1-2 five or more times within 12 consecutive months. Calls from frequent callers were categorized as pre-frequent calls (before reaching the threshold) and post-threshold calls (from the fifth call onward). Descriptive statistics were used to compare frequent callers with non-frequent callers, as well as subgroups of frequent callers based on call frequency. Overall, 214 091 individuals made 443 977 calls. Of these, 3.0% ( n = 6 415) were frequent callers, accounting for 19.9% ( n = 88 260) of all calls. “Unclear problem” was the most common contact cause across all groups, whereas “Alcohol/intoxication/overdose” and “Psychiatry – Suicidal” were only among the five most common contact causes in the post-threshold groups with the highest call volumes. High-priority dispatch was assigned to 89.6% of non-frequent calls, 84.3% of pre-frequent calls, and 73.1% of post-threshold calls. Telephone resolution without ambulance dispatch increased across groups (7.3%, 12.5%, and 23.8%, respectively), as did non-conveyance after dispatch (19.2%, 20.8%, and 27.4%). Differences became more pronounced with increasing post-threshold call volume. Frequent callers accounted for a substantial proportion of contacts to the Emergency Medical Dispatch Center. While pre-frequent calls resembled calls from non-frequent callers, post-threshold calls were more often resolved over the phone and less often resulted in hospital transport. Approval for performance of the study was given by the Emergency Medical Services in Region Zealand (p202519525).