Women have lower chances than men to be resuscitated and survive out-of-hospital cardiac arrest.

AIMS: Previous studies on sex differences in out-of-hospital cardiac arrest (OHCA) had limited scope and yielded conflicting results. We aimed to provide a comprehensive overall view on sex differences in care utilization, and outcome of OHCA. METHODS AND RESULTS: We performed a population-based cohort-study, analysing all emergency medical service (EMS) treated resuscitation attempts in one province of the Netherlands (2006-2012). We calculated odds ratios (ORs) for the association of sex and chance of a resuscitation attempt by EMS, shockable initial rhythm (SIR), and in-hospital treatment using logistic regression analysis. Additionally, we provided an overview of sex differences in overall survival and survival at successive stages of care, in the entire study population and in patients with SIR. We identified 5717 EMS-treated OHCAs (28.0% female). Women with OHCA were less likely than men to receive a resuscitation attempt by a bystander (67.9% vs. 72.7%; P < 0.001), even when OHCA was witnessed (69.2% vs. 73.9%; P < 0.001). Women who were resuscitated had lower odds than men for overall survival to hospital discharge [OR 0.57; 95% confidence interval (CI) 0.48-0.67; 12.5% vs. 20.1%; P < 0.001], survival from OHCA to hospital admission (OR 0.88; 95% CI 0.78-0.99; 33.6% vs. 36.6%; P = 0.033), and survival from hospital admission to discharge (OR 0.49, 95% CI 0.40-0.60; 33.1% vs. 51.7%). This was explained by a lower rate of SIR in women (33.7% vs. 52.7%; P < 0.001). After adjustment for resuscitation parameters, female sex remained independently associated with lower SIR rate. CONCLUSION: In case of OHCA, women are less often resuscitated by bystanders than men. When resuscitation is attempted, women have lower survival rates at each successive stage of care. These sex gaps are likely explained by lower rate of SIR in women, which can only partly be explained by resuscitation characteristics.

Sex differences in the association of comorbidity with shockable initial rhythm in out-of-hospital cardiac arrest.

BACKGROUND: Lower survival chances after out-of-hospital cardiac arrest (OHCA) in women is associated with lower odds of a shockable initial rhythm (SIR). We hypothesized that sex differences in the prevalence of SIR are due to sex differences in comorbidities. We aimed to establish to what extent sex differences in the cumulative comorbidity burden, measured using the Charlson Comorbidity Index (CCI), or in individual comorbidities, account for the lower proportion of SIR in women. METHODS: The association between CCI or its constituent comorbidities, and presence of SIR was studied using data (2010-2014) from a Dutch community-based OHCA registry, and included 2510 OHCA patients aged ≥18y with presumed cardiac cause. RESULTS: The mean age was 67.8 ± 13.8y, 71% were men. Women were more often in high CCI categories than men. However, moderate or high disease burden was associated with lower odds of SIR compared to no disease burden only in men (OR 99 %CI 0.73 [0.53-1.00] and OR 0.54 [0.37-0.80] P-trend < 0.001), but not in women (1.00 [0.58-1.72] and 1.02 [0.57-1.84 P-trend 0.93). Adding CCI to a multivariable model did not alter the OR of sex with SIR. Of the individual comorbidities, only previous myocardial infarction was both differently distributed between sexes (men 22.7% vs. women 13.1%, p < 0.001) and associated with odds of SIR (higher in both sexes). Adding this variable to the model changed the association of sex with initial rhythm from 0.49 (0.38-0.64) to 0.53 (0.41-0.69). CONCLUSION: Sex differences in comorbidities explained lower odds of SIR in women only modestly: differences in previous myocardial infarction contributed little, and cumulative comorbidity not at all.

Management of first responder programmes for out-of-hospital cardiac arrest during the COVID-19 pandemic in Europe.

AIM: First responder (FR) programmes dispatch professional FRs (police and/or firefighters) or citizen responders to perform cardiopulmonary resuscitation (CPR) and use automated external defibrillators (AED) in out-of-hospital cardiac arrest (OHCA). We aimed to describe management of FR-programmes across Europe in response to the Coronavirus Disease 2019 (COVID-19) pandemic. METHODS: In June 2020, we conducted a cross-sectional survey sent to OHCA registry representatives in 18 European countries with active FR-programmes. The survey was administered by e-mail and included questions regarding management of both citizen responder and FR-programmes. A follow-up question was conducted in October 2020 assessing management during a potential "second wave" of COVID-19. RESULTS: All representatives responded (response rate = 100%). Fourteen regions dispatched citizen responders and 17 regions dispatched professional FRs (9 regions dispatched both). Responses were post-hoc divided into three categories: FR activation continued unchanged, FR activation continued with restrictions, or FR activation temporarily paused. For citizen responders, regions either temporarily paused activation (n = 7, 50.0%) or continued activation with restrictions (n = 7, 50.0%). The most common restriction was to omit rescue breaths and perform compression-only CPR. For professional FRs, nine regions continued activation with restrictions (52.9%) and five regions (29.4%) continued activation unchanged, but with personal protective equipment available for the professional FRs. In three regions (17.6%), activation of professional FRs temporarily paused. CONCLUSION: Most regions changed management of FR-programmes in response to the COVID-19 pandemic. Studies are needed to investigate the consequences of pausing or restricting FR-programmes for bystander CPR and AED use, and how this may impact patient outcome.

European first responder systems and differences in return of spontaneous circulation and survival after out-of-hospital cardiac arrest: A study of registry cohorts.

BACKGROUND: In Europe, survival-rates after out-of-hospital cardiac arrest (OHCA) vary widely between regions. Whether a system dispatching First Responders (FRs; main FR-types: firefighters, police officers, citizen-responders) is present or not may be associated with survival-rates. This study aimed to assess the association between having a dispatched FR-system and rates of return of spontaneous circulation (ROSC) and survival across Europe. METHODS: Results of an inventory of dispatched FR-systems for OHCA in Europe were combined with aggregate ROSC and survival data from the EuReCa-TWO study and additionally collected data. Regression analysis (weighted on number of patients included per region) was performed to study the association between having a dispatched FR-system and ROSC and survival-rates to hospital discharge in the total population and in patients with shockable initial rhythm, witnessed OHCA and bystander cardiopulmonary resuscitation (CPR; Utstein comparator group). For regions without a dispatched FR-system, the theoretical survival-rate if a dispatched FR-system would have existed was estimated. FINDINGS: We included 27 European regions. There were 15,859 OHCAs in the total group and 2,326 OHCAs in the Utstein comparator group. Aggregate ROSC and survival-rates were significantly higher in regions with an FR-system compared to regions without (ROSC: 36% [95%CI 35%-37%] vs. 24% [95%CI 23%-25%]; P<0.001; survival in total population [N=15.859]: 13% [95%CI 12%-15%] vs. 5% [95%CI 4%-6%]; P<0.001; survival in Utstein comparator group [N=2326]: 33% [95%CI 30%-36%] vs. 18% [95%CI 16%-20%]; P<0.001), and in regions with more than one FR-type compared to regions with only one FR-type. All main FR-types were associated with higher survival-rates (all P<0.050). INTERPRETATION: European regions with dispatched FRs showed higher ROSC and survival-rates than regions without. FUNDING: This project/work has received funding from the European Union's Horizon 2020 research and innovation programme under acronym ESCAPE-NET, registered under grant agreement No 733381 (IO, HLT and MTB) and the European Union's COST programme under acronym PARQ, registered under grant agreement No CA19137 (IO, DC, HLT, MTB). HLT and MTB were supported by a grant from the Netherlands CardioVascular Research Initiative, Dutch Heart Foundation, Dutch Federation of University Medical Centres, Netherlands Organization for Health Research and Development, Royal Netherlands Academy of Sciences - CVON2017-15 RESCUED (HLT), and CVON2018-30 Predict2 (HLT and MTB).

The contribution of comorbidity and medication use to poor outcome from out-of-hospital cardiac arrest at home locations.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) at home is associated with lower rates of shockable initial rhythm and survival than OHCA in a public location. We determined whether medical history and medication use explain the association between OHCA location and presence of shockable initial rhythm and survival rate. METHODS: Data from ARREST, an OHCA registry in the Netherlands, were used (January 2009-December 2012). We assessed if OHCA location remained associated with a) presence of shockable initial rhythm and b) survival when taking medical history, medication use, resuscitation characteristics and demographics into account in a multivariable regression analysis. The relative contributions of the above mentioned variables to variance in both outcome measures was estimated using the Nagelkerke test. RESULTS: We included 1404 patients (1034 [73.6%] home OHCA, 370 [26.4%] public OHCA). OHCA location remained significantly associated with shockable initial rhythm (home 42.7%, public 78.1%; P < 0.01) and survival to hospital discharge (home 14.0%, public 45.7%; P < 0.01). Adding resuscitation characteristics to models of shockable initial rhythm and survival rate resulted in an increase in explained variance (13.0%-23.6%), whereas adding medical history or medication use to these models resulted in only a limited increase in explained variance (medical history to 27.6%, medication use to 30.0%). CONCLUSIONS: Comorbidity and medication use do not substantially contribute in explaining the poor outcome from out-of-hospital cardiac arrest occurring at home. Even when adjusted for medical history, medication use, resuscitation characteristics, and demographics, a large gap of unexplained variance in shockable initial rhythm and survival remains.

Comorbidity and survival in the pre-hospital and in-hospital phase after out-of-hospital cardiac arrest.

INTRODUCTION: Cumulative disease burden may be associated with survival chances after out-of-hospital cardiac arrest (OHCA). The relative contributions of cumulative disease burden on survival rates at the pre-hospital and in-hospital phases of post-resuscitation care are unknown. METHODS: The association between cumulative comorbidity burden as measured by the Charlson Comorbidity Index (CCI) and pre-hospital and in-hospital survival rates was studied using data (2010-2014) from a prospective OHCA registry in the Netherlands. The association between CCI and survival rate (overall survival [OHCA-hospital discharge], pre-hospital survival [OHCA-hospital admission] and in-hospital survival [hospital admission-hospital discharge]) was assessed using logistic regression analyses. The relative contributions of CCI on pre-hospital and in-hospital survival rates were determined using the Nagelkerke test. RESULTS: We included 2510 OHCA patients aged ≥18y. CCI was significantly associated with overall survival rate (OR 0.71; 95%CI 0.61-0.83; P < 0.01). CCI was not associated with pre-hospital survival rate (OR 0.96; 95%CI 0.76-1.23; P = 0.92) whereas high CCI was significantly associated with low in-hospital survival rate (OR 0.41; 95%CI 0.27-0.62; P = 0.01). The relative contributions of CCI on pre-hospital and in-hospital survival were 1.1% and 8.1%, respectively. CONCLUSION: Pre-existing high comorbidity burden plays a modest role in reducing survival rate after OHCA, and only in the in-hospital phase. The present study offers data that may guide clinicians in discussing resuscitation options during advance care planning with patients with high comorbidity burden. This may be helpful in creating a patients' informed choice.

Occurrence of shockable rhythm in out-of-hospital cardiac arrest over time: A report from the COSTA group.

BACKGROUND: Prior research suggests that the proportion of a shockable initial rhythm in out-of-hospital cardiac arrest (OHCA) declined during the last decades. This study aims to investigate if this decline is still ongoing and explore the relationship between location of OHCA and proportion of a shockable initial rhythm as initial rhythm. METHODS: We calculated the proportion of patients with a shockable initial rhythm between 2006-2015 using pooled data from the COSTA-group (Copenhagen, Oslo, Stockholm, Amsterdam). Analyses were stratified according to location of OHCA (residential vs. public). RESULTS: A total of 19,054 OHCA cases were included. Overall, the total proportion of cases with a shockable initial rhythm decreased from 42% to 37% (P < 0.01) from 2006 to 2015. When stratified according to location, the proportion of cases with a shockable initial rhythm decreased for OHCAs at a residential location (34% to 27%; P = 0.03), while the proportion of a shockable initial rhythm was stable among OHCAs in public locations (59%-57%; P = 0.2). During the last years of the study period (2011-2015), the overall proportion of a shockable initial rhythm remained stable (38%-37%; P = 0.45); this was observed for both residential and public OHCA. CONCLUSION: We found a decline in the proportion of patients with a shockable initial rhythm in OHCAs at a residential location; this decline levelled off during the second half of the study period (2011-2015). In public locations, we observed no decline in shockable initial rhythm over time.

Factors that motivate individuals to volunteer to be dispatched as first responders in the event of a medical emergency: A systematic review protocol.

Background: Voluntary First Response is an important component of prehospital care for medical emergencies, particularly cardiac arrest, in many countries. This intervention entails the mobilisation of volunteers, known as Community First Responders (CFRs), by the Emergency Medical Services to respond to medical emergencies in their locality. They include lay responders and/or professional responders (e.g. police officers, fire fighters, and general practitioners). A wide variety of factors are thought to motivate CFRs to join and remain engaged in Voluntary First Response schemes, such as the availability of learning opportunities, recognition, counselling, and leadership. The aim of this review is to develop an in-depth understanding of CFR motivation, including the factors that influence the initial decision to volunteer as a CFR and the factors that sustain involvement in Voluntary First Response over time. Any factors relevant to CFR de-motivation and turnover will also be examined. Methods: This is a protocol for a qualitative systematic review of the factors that influence the motivation of individuals to participate in Voluntary First Response. A systematic search will be carried out on seven electronic databases. Qualitative studies, mixed-methods studies, and any other studies producing data relating to the review question will be eligible for inclusion. Title and abstract screening, as well as full text screening, will be completed independently by two authors. A narrative synthesis, which is an established qualitative synthesis methodology, will be performed. The quality of each of the included studies will be critically appraised. Discussion: The findings of this review will be used to optimise the intervention of Voluntary First Response. Specifically, the results will inform the design and organisation of Voluntary First Response schemes, including their recruitment, training, and psychological support processes. This could benefit a range of stakeholders, including CFRs, paramedics, emergency physicians, patients, and the public.

Socio-economic differences in incidence, bystander cardiopulmonary resuscitation and survival from out-of-hospital cardiac arrest: A systematic review.

BACKGROUND: Individuals with a low socioeconomic status (SES) may have a greater mortality rate from out of hospital cardiac arrest (OHCA) than those with a high SES. We explored whether SES disparities in OHCA mortality manifest in the incidence of OHCA, the chance of receiving bystander cardiopulmonary resuscitation (CPR) or in the chance of surviving an OHCA. We also studied whether sex and age differences exist in such SES disparities. METHODS: The Medline, Embase and Scopus databases were searched from 01-01-1993 until 31-01-2019. Studies utilising any study design or population were included. Studies were included if the exposure was SES of the OHCA victim or the OHCA location and the outcome was either OHCA incidence, CPR provision and/or survival rate after OHCA. Study selection and quality assessment were conducted by two reviewers independently. Descriptive data and measures of association were extracted, both in the total study population and in subgroups stratified by age and/or sex. This review was carried out following the PRISMA guidelines. RESULTS: Overall 32 studies were included. Twelve studies reported on OHCA incidence, thirteen on bystander CPR provision and fourteen on survival. Some evidence for SES differences was found in each identified stage. In all the studies on incidence, SES was measured over the area of the OHCA victims' residence and was consistently associated with OHCA. In studies on bystander CPR, SES of the area in which the OHCA occurred was associated with bystander CPR, while evidence on individual SES was lacking. In studies on OHCA survival, SES of the victim measured at the individual level and SES of the area in which the OHCA occurred were associated, while SES of the victim, measured at the area of residence was not. Studies reporting age and sex differences in the SES trends were scarce. CONCLUSION: SES disparities in OHCA mortality likely manifest in OHCA incidence, bystander CPR provision and survival rate after OHCA. However, there is a distinct lack of data on SES measured at the individual level and on differences within subgroups, e.g. by sex and age.

First-response treatment after out-of-hospital cardiac arrest: a survey of current practices across 29 countries in Europe.

BACKGROUND: In Europe, survival rates after out-of-hospital cardiac arrest (OHCA) vary widely. Presence/absence and differences in implementation of systems dispatching First Responders (FR) in order to arrive before Emergency Medical Services (EMS) may contribute to this variation. A comprehensive overview of the different types of FR-systems used across Europe is lacking. METHODS: A mixed-method survey and information retrieved from national resuscitation councils and national EMS services were used as a basis for an inventory. The survey was sent to 51 OHCA experts across 29 European countries. RESULTS: Forty-seven (92%) OHCA experts from 29 countries responded to the survey. More than half of European countries had at least one region with a FR-system. Four categories of FR types were identified: (1) firefighters (professional/voluntary); (2) police officers; (3) citizen-responders; (4) others including off-duty EMS personnel (nurses, medical doctors), taxi drivers. Three main roles for FRs were identified: (a) complementary to EMS; (b) part of EMS; (c) instead of EMS. A wide variation in FR-systems was observed, both between and within countries. CONCLUSIONS: Policies relating to FRs are commonly implemented on a regional level, leading to a wide variation in FR-systems between and within countries. Future research should focus on identifying the FR-systems that most strongly influence survival. The large variation in local circumstances across regions suggests that it is unlikely that there will be a 'one-size fits all' FR-system for Europe, but examining the role of FRs in the Chain of Survival is likely to become an increasingly important aspect of OHCA research.