Effectiveness of chain of survival for out-of-hospital-cardiac-arrest (OHCA) in resource limited countries: A systematic review.

Aim: Given the critical disparities in survival for out-of-hospital-cardiac-arrest (OHCA) in resource limited countries and the lack of context-specific evidence to guide resuscitation practices, we aimed to systematically evaluate the effectiveness of the chain of survival components including bystander response, emergency medical services (EMS) response, advanced life support, and post-resuscitation care on outcomes such as return of spontaneous circulation, survival to admission, survival to hospital discharge, and neurological outcomes in these settings. Methods: This systematic review, following PRISMA guidelines, included observational and interventional studies on OHCA management from low, lower-middle, and upper-middle-income countries, published in English (2004-2023). PubMed, Embase, CINAHL, and Cochrane Library were searched using predefined terms. Two reviewers independently screened studies, extracted data using the Utstein template, and resolved conflicts with a third reviewer. Data included pre-hospital, patient, and post-resuscitation care factors, as well as short and long-term outcomes. Descriptive analysis and narrative synthesis were conducted, with return of spontaneous circulation (ROSC) rates compared across income groups using Results: Sixteen (16) eligible studies were included. No study was found from low-income countries. ROSC rates ranged from 0.7% to 44%, survival to discharge from 0.6% to 14.1%, and good neurological outcomes (CPC 1-2) from 0.6% to 53.8%. While upper-middle-income countries showed slightly higher ROSC rates, differences were not statistically significant. Risk of bias was moderate to high due to selection bias, inadequate confounding control, and inconsistent reporting. These findings emphasize the need for standardized reporting and further research to improve outcomes in resource limited countries. Conclusion: This review highlights low survival rates for OHCA in resource limited countries, with significant variability and gaps in evidence. Strengthening EMS systems, adopting context-specific strategies, and standardizing reporting are critical to improving outcomes.