Ethnic disparities in the incidence and outcome from out-of-hospital cardiac arrest: A New Zealand observational study

BACKGROUND: New Zealand (NZ) has an ethnically diverse population. International studies have demonstrated significant differences in health equity by ethnicity; however, there is limited evidence in the context of out-of-hospital cardiac arrest in NZ. We investigated whether heath disparities in incidence and outcome of out-of-hospital cardiac arrest exist between NZ ethnic groups. METHOD: A retrospective observational study was conducted using NZ cardiac arrest registry data for a 2-year period. Ethnic cohorts investigated were the indigenous Māori population, Pacific Peoples and European/Others. Incidence rates, population characteristics and outcomes (Return of Spontaneous Circulation sustained to hospital handover and thirty-day survival) were compared. RESULTS: Age-adjusted incidence rates per 100,000 person-years were higher in Māori (144.4) and Pacific Peoples (113.5) compared to European/Others (93.8). Return of spontaneous circulation sustained to hospital handover was significantly lower in Māori (adjusted OR 0.74, 95% CI 0.64-0.87, p < 0.001). Survival to thirty-days was lower for both Māori (adjusted OR 0.61, 95% CI 0.48-0.78, p < 0.001) and Pacific Peoples (adjusted OR 0.52, 95% CI 0.37-0.72, p < 0.001). A higher proportion of events occurred in all age groups below 65 years old in Māori and Pacific Peoples (p < 0.001), and a higher proportion of events occurred among women in Māori and Pacific Peoples (p < 0.001). CONCLUSIONS: There are significant differences in health equity by ethnicity. Both Māori and Pacific Peoples have higher incidence of out-of-hospital cardiac arrest and at a younger age. Māori and Pacific Peoples have lower rates of survival to thirty-days. Our results provide impetus for targeted health strategies for at-risk ethnic populations.