Abstract Body (Do not enter title and authors here): Introduction
Out-of-hospital cardiac arrest (OHCA) is a critical public health concern. Effective and timely cardio-pulmonary resuscitation (CPR) is crucial to survival. Our review aims to evaluate the prevalence, trends and barriers to layperson bystander CPR in regions with limited resources, low public health awareness, and variable emergency medical services (EMS).

Methods
We screened PubMed, Google Scholar, Embase, and Scopus for eligible articles in the last 10 years. Out of 806 studies screened, 7 studies were included in the final review. The protocol was registered on PROSPERO. Two reviewers independently performed screening and bias assessments, with any disagreements resolved by a third reviewer.

Results
Seven observational studies (n=2956) with adult OHCA cases, and published between 2016 and 2024 were included in the review. 5 studies were from India and 2 from Pakistan, with no data from other South Asian countries. A male predominance (n=2160) and a high prevalence of prior cardiovascular comorbidities (n=929) were observed in OHCA cases. Most OHCAs occurred at home (n=1723), with mean and median ages ranging from 54.9 to 68 years. Layperson bystander CPR was provided in 170 cases. 71 of these achieved return of spontaneous circulation (ROSC). Krishna et al. found improved survival outcomes with CPR durations under 30 minutes (p=0.04). Vampu et al. reported that continuous CPR en route to the hospital significantly increased survival to hospital (RR = 9.05; 95% CI: 3.59–22.8; p < 0.001). Factors positively associated with ROSC and survival included shockable rhythms (OR=18.97; p < 0.001) and shorter arrest durations (OR = 0.937 per minute; p = 0.047). 3 studies reported data on survival to hospital discharge (n for CPR cases vs all OHCA cases: 23 vs 26). Neurological recovery among survivors was favorable but limited in number (CPC ≤ 2 in greater than 50% of recovered cases). Clerk et al. reported more favorable neurological outcomes in females (9%) than in males (5.6%) (p=0.004). Barriers to CPR implementation included lack of awareness, cultural hesitations, and legal fears. EMS integration was low (CPR delivery of 21% and no AED use).

Conclusion
Bystander CPR prevalence in South Asia falls below global standards. Limited awareness and cultural barriers impacts implementation and survival. Initiatives aimed at enhancing community training, and improving EMS integration are vital for better outcomes in OHCA cases in South Asia.