# Where you live matters: socioeconomic disparities in out-of-hospital cardiac arrest incidence and survival in Western Australia – A population-based cohort study

## TL;DR

People in more disadvantaged areas in Western Australia face higher rates of out-of-hospital cardiac arrests and lower survival chances.

## Contribution

This study uses fine spatial resolution data to show socioeconomic disparities in OHCA incidence and survival in Western Australia.

## Key findings

- OHCA incidence was 193.81 per 100,000 in the most disadvantaged areas, dropping to 73.18 in the least disadvantaged.
- Patients in the least disadvantaged areas had 67% higher odds of 30-day survival after OHCA.
- Socioeconomic status was linked to both higher OHCA incidence and poorer survival outcomes.

## Abstract

•OHCA incidence increased with increasing socioeconomic disadvantage.•OHCA survival declined with increasing socioeconomic disadvantage.•High SES patients had 67% greater odds of survival than low SES patients.•SES was assigned using small-area (SA1) data, providing finer spatial resolution.

OHCA incidence increased with increasing socioeconomic disadvantage.

OHCA survival declined with increasing socioeconomic disadvantage.

High SES patients had 67% greater odds of survival than low SES patients.

SES was assigned using small-area (SA1) data, providing finer spatial resolution.

Investigate socioeconomic differences in the incidence and odds of survival of adult out-of-hospital cardiac arrests [OHCA] in Western Australia [WA].

OHCA data for patients aged 15 years and older were sourced for the period 2015–2024 for WA. Socioeconomic status was classified using the Australian Bureau of Statistics Index of Relative Socio-Economic Disadvantage. Socioeconomic status was attributed based on each patient’s residential address and classified in quintiles. Crude and age-standardised incidence rates per 100,000 adult population was calculated for all OHCA. Survival (return of spontaneous circulation at hospital arrival and survival to 30-days) was assessed for resuscitation-attempted OHCA with medical aetiology. Incidence by socioeconomic quintile was modelled using negative binomial linear regression, and odds of survival by socioeconomic quintile using logistic regression.

A total of 23,975 OHCAs were attended by emergency medical services in WA, with a crude incidence of 117.34 per 100,000 population per year. Outcomes varied across the socioeconomic gradient, with higher incidence and poorer survival in more disadvantaged populations. Incidence decreased from 193.81/100,000 in the most disadvantaged quintile to 73.18/100,000 in the least disadvantaged quintile (p < 0.001). Among resuscitation-attempted medical OHCA, patients in the least disadvantage areas had 67% greater odds of 30-day survival than those in the most disadvantaged areas (OR: 1.67; 95%CI: 1.28–2.18).

Greater socioeconomic disadvantage is associated with a greater incidence of OHCA and poorer survival outcomes.