Patient factors associated with conveyance decision-making by Emergency Medical Services professionals in patients with a syncope: a cross-sectional factorial survey design

Abstract

Background: The clinical decision-making of non-conveyance is perceived as complex and difficult by emergency medical services (EMS) professionals. Patients with a transient loss of consciousness (TLOC) based on syncope constitute a significant part of the non-conveyance population. Risk stratification is the basis of the clinical decision-making process by EMS professionals. This risk stratification is based on various patient factors. This study aimed to explore patient factors significantly associated with conveyance decision-making by EMS professionals in patients with a TLOC based on syncope.

Methods: A cross-sectional vignette study with a factorial survey design was conducted. Patient factors were derived from the "National Protocol Ambulance Care", and all possible combinations of these factors and underlying categories were combined, resulting in 256 unique vignettes (2*4*4*4*2 = 256). Patient factors presented either low-risk or high-risk factors for adverse events. Data were collected through an online questionnaire, in which participants received a random sample of 15 vignettes. For each vignette, the respondent indicated whether the patient would need to be conveyed to the emergency department or not. A multilevel logistic regression analysis with stepwise backward elimination was performed to analyse factors significantly associated with conveyance decision-making. In the logistic model, we modelled the probability of non-conveyance.

Results: 110 respondents were included, with 1646 vignettes being assessed. Mean age 45.5 (SD 9.3), male gender 63.6%, and years of experience 13.2 (SD 8.9). Multilevel analysis showed two patient factors contributing significantly to conveyance decision-making: 'red flags' and 'prehospital electrocardiogram (ECG)'. Of these patient factors, three underlying categories were significantly associated with non-conveyance: 'sudden cardiac death < 40 years of age in family history' (OR 0.33, 95% CI 0.22-0.50; p < 0.001), 'cardiovascular abnormalities, pulmonary embolism or pulmonary hypertension in the medical history' (OR 0.62, 95% CI 0.43-0.91; p = 0.01), and 'abnormal prehospital ECG' (OR 0.54, 95% CI 0.41-0.72; p < 0.001).

Conclusion: Sudden cardiac death < 40 years of age in family history, medical history, and abnormal ECG are significantly negatively associated with non-conveyance decision-making by EMS professionals in patients with a TLOC based on syncope. Low-risk factors do not play a significant role in conveyance decision-making.

Keywords: Ambulance care; Emergency medical services; Transient loss of consciousness; Vignette study.