BackgroundPrehospital vital sign documentation in paediatric patients is incomplete, especially in patients ≤ 2 years. The aim of the study was to increase vital sign registration in paediatric patients through specific educational initiatives.MethodsProspective quasi-experimental study with interrupted time-series design in the North Denmark and South Denmark regions. The study consecutively included all children aged < 18 years attended by the emergency medical service (EMS) from 1 July 2019 to 31 December 2021. Specific educational initiatives were conducted only in the North Denmark EMS and included video learning and classroom training based on the European Paediatric Advanced Life Support principles. The primary outcome was the proportion of patients who had their respiratory rate, peripheral capillary oxygen saturation, heart rate and level of consciousness recorded at least twice. We used a binomial regression model stratified by age groups to compare proportions of the primary outcome in the pre- and post-intervention periods in each region.ResultsIn North Denmark, 7551 patients were included, while 15,585 patients from South Denmark were used as a reference. Virtually all of the North Denmark EMS providers completed the video learning (98.7%). The total study population involved patients aged ≤ 2 months (5.5%), 3–11 months (7.4%), 1–2 years (18.8%), 3–7 years (16.2%) and ≥ 8 years (52.1%). In the intervention region, the primary outcome increased from the pre- to the post-intervention period from 35.3% to 40.5% [95% CI for difference 3.0;7.4]. There were large variations in between age groups with increases from 18.8% to 27.4% [95% CI for difference 5.3;12.0] among patients aged ≤ 2 years, from 33.5% to 43.7% [95% CI for difference 4.9;15.5] among patients aged 3–7 years and an insignificant increase among patients aged ≥ 8 years (from 46.4% to 47.9% [95% CI for difference − 1.7;4.7]). In the region without the specific educational interventions, proportions were steady for all age groups throughout the entire study period.ConclusionsMandatory educational initiatives for EMS providers were associated with an increase in the extent of vital sign registration in paediatric patients ≤ 7 years. Incomplete vital registration was associated with, but not limited to non-urgent cases.