Is there an association between 30-day mortality from out-of-hospital cardiac arrest (OHCA) and deprivation levels within Hampshire? A retrospective cohort study.

Introduction: People who live in population-dense areas, work in routine occupations, originate from a non-white background, have lower education attainment and experience a greater level of deprivation have an increased risk of suffering an OHCA and are less likely to receive bystander CPR. This study seeks to understand if these observed inequalities result in reduced survival by examining the relationship between deprivation and survival at 30 days at a UK single county level. Methods: 30-day survival from non-traumatic OHCA in adults over 18 years of age in Hampshire from local ambulance service data (Jan 2019 - March 2023) was combined with indices of multiple deprivation (IMD) based on the home postcode. Multivariable logistic regression models were developed, through bidirectional stepwise regression, to evaluate the effect of deprivation on 30-day survival. Separate models were developed to consider non-linear relationships before a final model incorporated learning from previous iterations. Results: Overall, 4184 patients were included in the final analysis, with 437 (10%) surviving to 30 days. Age of OHCA patients varied significantly between IMD deciles (p < 0.01), with a trend to younger patients in more deprived deciles. Univariable regression found no relationship between deprivation and survival. However, after controlling for age, sex, shockable rhythm and bystander CPR, increasing deprivation was associated with reduced survival (OR: 1.05, 95% CI 1.01-1.09). Other significant predictors were age, shockable rhythm and bystander CPR. Conclusion: Increasing deprivation was associated with a reduced 30-day survival after accounting for other measured variables.