BackgroundNot all patients where an ambulance is dispatched are conveyed to an emergency department. Although non-conveyance is a substantial part of ambulance care, there is limited insight in the non-conveyance patient population. Therefore, the study aim was to compare demographics, initial on-scene reasons for care, and vital signs between conveyed and non-conveyed patients attended by an ambulance.MethodsA retrospective study of ambulance runs from 2 EMS regions in the Netherlands in 2016 was performed. For each ambulance run demographics (age, gender and geographical location), initial reasons for care categorised into the ICD-10 classification system, and vital functions or observational scales (according to the national ambulance care protocol) were collected and analyzed.Results54.797 ambulance runs met the inclusion criteria, of which 14.383/54.797 (26.2%) resulted in non-conveyance. There was no significant difference in gender, but the non-conveyance group was significantly younger (48.5 (±26.4) years) compared to the conveyance group (60.7 (±22.2) years) (p = .000). The most common initial reasons for care for the conveyance group could be classified into chapter-9 diseases of the circulatory system, chapter-19 injury, poisoning and certain other consequences of external causes, and chapter-10 diseases of the respiratory system. The most common reasons for care in the non-conveyance group could be classified into the chapter-9 diseases of the circulatory system, chapter-19 injury, poisoning and certain other consequences of external causes, and -chapter-5 mental, behavioral and neurodevelopmental disorders. The total percentage abnormal vital functions/observation scales between the conveyance (69.5%) and non-conveyance group (58.6%) was significantly different (p = .000). 15 out of 17 vital functions/observation scales are significantly different between the conveyance and non-conveyance group.ConclusionsThis study shows that non-conveyed patients are younger, are more likely to be in (highly) rural areas, and more often have initial reasons for care related to mental, behavioral and neurodevelopmental disorders (ICD-10 chapter 5). Although abnormal vital functions/observation scale were more prevalent in the conveyance group, 58.6% of the non-conveyed patients had at least one abnormal vital function/observation scale.