Ambulance crew-initiated non-conveyance in the Helsinki EMS system-A retrospective cohort study.

Background: Ambulance patients are usually transported to the hospital in the emergency medical service (EMS) system. The aim of this study was to describe the non-conveyance practice in the Helsinki EMS system and to report mortality following non-conveyance decisions.

Methods: All prehospital patients ≥16 years attended by the EMS but not transported to a hospital during 2013-2017 were included in the study. EMS mission- and patient-related factors were collected and examined in relation to patient death within 30 days of the EMS non-conveyance decision.

Results: The EMS performed 324,207 missions with a patient during the study period. The patient was not transported in 95,909 (29.6%) missions; 72,233 missions met the study criteria. The patient mean age (standard deviation) was 59.5 (22.5) years; 55.5% of patients were female. The most common dispatch codes were malaise (15.0%), suspected decline in vital signs (14.0%), and falling over (12.9%). A total of 960 (1.3%) patients died within 30 days after the non-conveyance decision. Multivariate logistic regression analysis revealed that mortality was associated with the patient's inability to walk (odds ratio 3.19, 95% confidence interval 2.67-3.80), ambulance dispatch due to shortness of breath (2.73, 2.27-3.27), decreased level of consciousness (2.72, 1.75-4.10), decreased blood oxygen saturation (2.64, 2.27-3.06), and abnormal systolic blood pressure (2.48, 1.79-3.37).

Conclusion: One-third of EMS missions did not result in patient transport to the hospital. Thirty-day mortality was 1.3%. Abnormalities in multiple respiratory-related vital signs were associated with an increased likelihood of death within 30 days.