Association of socioeconomic status with 30-day survival following out-of-hospital cardiac arrest in Scotland, 2011-2020.

BACKGROUND AND AIMS: The aim of this study was to investigate the crude and adjusted association of socioeconomic status with 30-day survival after out-of-hospital cardiac arrest (OHCA) in Scotland and to assess whether the effect of this association differs by sex or age. METHODS: This is a population-based, retrospective cohort study, including non-traumatic, non-Emergency Medical Services witnessed patients with OHCA where resuscitation was attempted by the Scottish Ambulance Service, between April 1, 2011 and March 1, 2020. Socioeconomic status was defined using the Scottish Index of Multiple Deprivation (SIMD). The primary outcome was 30-day survival after OHCA. Crude and adjusted associations of SIMD quintile with 30-day survival after OHCA were estimated using logistic regression. Effect modification by age and sex was assessed by stratification. RESULTS: Crude analysis showed lower odds of 30-day survival in the most deprived quintile relative to least deprived (OR 0.74, 95%CI 0.63-0.88). Adjustment for age, sex and urban/rural residency decreased the relative odds of survival further (OR 0.56, 95%CI 0.47-0.67). The strongest association was observed in males < 45 years old. Across quintiles of increasing deprivation, evidence of decreasing trends in the proportion of those presenting with shockable initial cardiac rhythm, those receiving bystander cardiopulmonary resuscitation and 30-day survival after OHCA were found. CONCLUSIONS: Socioeconomic status is associated with 30-day survival after OHCA in Scotland, favouring people living in the least deprived areas. This was not explained by confounding due to age, sex or urban/rural residency. The strongest association was observed in males < 45 years old.

Association between sex and survival after out-of-hospital cardiac arrest: A systematic review and meta-analysis.

The current literature on sex differences in 30-day survival following out-of-hospital cardiac arrest (OHCA) is conflicting, with 3 recent systematic reviews reporting opposing results. To address these contradictions, this systematic literature review and meta-analysis aimed to synthesize the literature on sex differences in survival after OHCA by including only population-based studies and through separate meta-analyses of crude and adjusted effect estimates. MEDLINE and Embase databases were systematically searched from inception to March 23, 2022 to identify observational studies reporting sex-specific 30-day survival or survival until hospital discharge after OHCA. Two meta-analyses were conducted. The first included unadjusted effect estimates of the association between sex and survival (comparing males vs females), whereas the second included effect estimates adjusted for possible mediating and/or confounding variables. The PROSPERO registration number was CRD42021237887, and the search identified 6712 articles. After the screening, 164 potentially relevant articles were identified, of which 26 were included. The pooled estimate for crude effect estimates (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.22-1.66) indicated that males have a higher chance of survival after OHCA than females. However, the pooled estimate for adjusted effect estimates shows no difference in survival after OHCA between males and females (OR, 0.93; 95% CI, 0.84-1.03). Both meta-analyses involved high statistical heterogeneity between studies: crude pooled estimate I2 = 95.7%, adjusted pooled estimate I2 = 91.3%. There does not appear to be a difference in survival between males and females when effect estimates are adjusted for possible confounding and/or mediating variables in non-selected populations.

Incidence, characteristics and outcomes of out-of-hospital cardiac arrests in patients with psychiatric illness: A systematic review.

AIM: To conduct a systematic literature review of the existing evidence on incidence, characteristics and outcomes after out-of-hospital cardiac arrest (OHCA) in patients with psychiatric illness. METHODS: We searched Embase, Medline, PsycINFO and Web of Science using a comprehensive electronic search strategy to identify observational studies reporting on OHCA incidence, characteristics or outcomes by psychiatric illness status. One reviewer screened all titles and abstracts, and a second reviewer screened a random 10%. Two reviewers independently performed data extraction and quality assessment. RESULTS: Our search retrieved 11,380 studies, 10 of which met our inclusion criteria (8 retrospective cohort studies and two nested case-control studies). Three studies focused on depression, whilst seven included various psychiatric conditions. Among patients with an OHCA, those with psychiatric illness (compared to those without) were more likely to have: an arrest in a private location; an unwitnessed arrest; more comorbidities; less bystander cardiopulmonary resuscitation; and an initial non-shockable rhythm. Two studies reported on OHCA incidence proportion and two reported on survival, showing higher risk, but lower survival, in patients with psychiatric illness. CONCLUSION: Psychiatric illness in relation to OHCA incidence and outcomes has rarely been studied and only a handful of studies have reported on OHCA characteristics, highlighting the need for further research in this area. The scant existing literature suggests that psychiatric illness may be associated with higher risks of OHCA, unfavourable characteristics and poorer survival. Future studies should further investigate these links and the role of potential contributory factors such as socioeconomic status and comorbidities.