Estimating bystander CPR using a strict documentation-based definition: a multiregional EMS registry analysis.
BMC emergency medicine · 2026-06-05 · Registry study
Abstract
INTRODUCTION: Bystander cardiopulmonary resuscitation (CPR) is a key determinant of survival after out-of-hospital cardiac arrest (OHCA), yet engagement remains low and varies across regions. Reliable estimation of bystander CPR prevalence depends on consistent documentation within emergency medical services (EMS) registries. In Saudi Arabia, national evidence on documentation-based prevalence and system-level determinants remains limited. AIM: To estimate the prevalence of strictly documented bystander CPR, assess data completeness and potential outcome misclassification, examine regional variation, and identify independent predictors of bystander CPR among OHCA cases attended by the Saudi Red Crescent Authority (SRCA). METHODS: We conducted a retrospective cross-sectional analysis of the SRCA OHCA registry (January-June 2024). Bystander CPR was defined conservatively, requiring explicit documentation of CPR initiation prior to SRCA arrival by a non-SRCA individual. Cases lacking clear attribution were classified as unclassifiable. Regional variation was described, and multivariable logistic regression estimated adjusted associations with patient characteristics, witnessed status, EMS response time, and region. RESULTS: Among 6,378 OHCA records, bystander CPR status was classifiable in 5,271 cases (82.6%), while 1,107 cases (17.4%) were unclassifiable under the strict definition. Among classifiable cases, bystander CPR was documented in 646 cases (12.3%). In the complete-case model (N = 4,267), witnessed arrest was strongly associated with higher odds of bystander CPR (aOR = 5.15, 95% CI 4.20-6.31). Longer EMS response time was associated with lower odds (aOR = 0.98 per minute, 95% CI 0.97-1.00), and male sex was associated with higher odds (aOR = 1.26, 95% CI 1.03-1.53). Significant regional disparities persisted after adjustment. CONCLUSION: Using a conservative documentation-based definition, bystander CPR engagement in SRCA-attended OHCA cases remains low and uneven across regions. Substantial variation in documentation completeness highlights the importance of standardized reporting for accurate surveillance and benchmarking. Strengthening dispatcher-assisted CPR, expanding population-level training, and enhancing registry harmonization may improve early resuscitation response across SRCA-attended EMS settings in Saudi Arabia.
Tags
Bystanders & volunteers · Equity & disparities · Time intervals