# Association Between Urban–Rural Geographical Location and 30-Day Survival After Out-of-Hospital Cardiac Arrest

## TL;DR

This study finds that people in rural areas have lower survival rates after cardiac arrest compared to urban areas, possibly due to slower emergency response times.

## Contribution

The study identifies rural-urban survival disparities in OHCA and suggests early defibrillation as a key mediator.

## Key findings

- Rural OHCA patients have lower 30-day survival odds compared to urban patients.
- Early EMS arrival time is linked to better survival and may mediate rural-urban disparities.
- Reducing defibrillation delay could improve survival in rural areas.

## Abstract

The aim of this study is to investigate the association between the urban–rural geographical location of out-of-hospital cardiac arrest (OHCA) and 30-day survival after OHCA in Scotland.

For these analyses, data from a population-based study were utilized. In this cohort, all adult, nonemergency medical services (EMS)–witnessed patients with nontraumatic OHCA, for whom the Scottish Ambulance Service attempted resuscitation between April 1, 2011, and March 1, 2020, were included. We used the 2-fold and 6-fold urban-rural classification determined by the Scottish Government to classify cases in our cohort. We used 30-day survival after OHCA as an outcome measure. We performed univariable and multivariable logistic regression to assess the association between urban–rural geographical locations of OHCA and 30-day survival after OHCA. Furthermore, we conducted a mediation analysis to identify potential mediators.

This cohort included 20,378 OHCA cases. Patients living in rural areas have a lower odds of 30-day survival after OHCA compared with people living in urban areas (adjusted odds ratio, 1.19; 95% CI, 1.02 to 1.40; adjusted for age, sex, and the Scottish Index of Multiple Deprivation. Early EMS arrival time (a likely proxy for time to first defibrillation) was associated with improved 30-day survival after OHCA and was identified as a probable mediator explaining part of the association found between urban–rural geographical location of OHCA and 30-day survival after OHCA.

Policies focusing on reducing time to first defibrillation are likely to be most effective in reducing the difference in 30-day survival after OHCA between urban and rural communities.