Variability exists in the management of childhood syncope as clinicians balance resource utilization with the need to identify serious diseases. Limited evidence exists regarding the long-term impact of evidence-based guidelines (EBGs) on clinical practices. This study's objective was to measure long-term changes in the management of syncope after implementing a syncope EBG in a single pediatric emergency department following the redistribution of resources to facilitate compliance over time.

Methods: We included healthy patients aged 8-22 years, presenting to the pediatric emergency department with syncope between 2009 and 2017. Interrupted time series analysis compared testing rates and length of stay among the pre-EBG, short-term follow-up, and long-term follow-up periods.

Results: The study included 1,294 subjects. From the pre-EBG period to the long-term follow-up period, recommended electrocardiogram and urine pregnancy test rose significantly [level change odds ratio (95% confidence interval) 5.56 (1.73-17.91) and 3.15 (1.07-9.32), respectively]. Testing and management not recommended by the EBG decreased significantly, including complete blood count, electrolytes, point-of-care glucose, chest radiograph, and intravenous fluids [level change odds ratio (95% confidence interval) 0.19 (0.09-0.40), 0.15 (0.07-0.32), 0.38 (0.18-0.81), 0.17 (0.06-0.49), and 0.18 (0.08-0.39), respectively]. Length of stay declined significantly. No delayed diagnoses occurred.

Conclusions: Sustained improvements in syncope management persisted during long-term follow-up of the EBG despite minimal resources. The EBG was associated with increased focused evaluation and decreased low yield testing. EBGs may be useful tools to influence sustained clinical practices to promote safe, cost-effective, and high-quality care.