International variation in survival after out-of-hospital cardiac arrest : A validation study of the Utstein template

Introduction: Out-of-hospital cardiac arrest (OHCA) survival varies greatly between communities. The Utstein template was developed and promulgated to improve the comparability of OHCA outcome reports, but it has undergone limited empiric validation. We sought to assess how much of the variation in OHCA survival between emergency medical services (EMS) across the globe is explained by differences in the Utstein factors. We also assessed how accurately the Utstein factors predict OHCA survival. Methods: We performed a retrospective analysis of patient-level prospectively collected data from 12 OHCA registries from 12 countries for the period 1 Jan 2006 through 31 Dec 2011. We used generalized linear mixed models to examine the variation in survival between EMS agencies (n = 232). Results: Twelve registries contributed 86,759 cases. Patient arrest characteristics, EMS treatment and patient outcomes varied across registries. Overall survival to hospital discharge was 10% (range, 6% to 22%). Overall survival with Cerebral Performance Category of 1 or 2 (available for 8/12 registries) was 8%(range, 2% to 20%). The area-under-the-curve for the Utstein model was 0.85 (Wald CI: 0.85-0.85). The Utstein factors explained 51% of the EMS agency variation in OHCA survival. Conclusions: The Utstein factors explained 51%. of the variation in survival to hospital discharge among multiple large geographically separate EMS agencies. This suggests that quality improvement and public health efforts should continue to target modifiable Utstein factors to improve OHCA survival. Further study is required to identify the reasons for the variation that is incompletely understood.Peer reviewe

Psychosis risk as a function of age at onset: A comparison between early- and late-onset psychosis in a general population sample

This paper proposes a partial-order semantics for a stochastic process algebra that supports general (non-memoryless) distributions and combines this with an approach to numerically analyse the first passage time of an event. Based on an adaptation of McMillan's complete finite prefix approach tailored to event structures and process algebra, finite representations are obtained for recursive processes. The behaviour between two events is now captured by a partial order that is mapped on a stochastic task graph, a structure amenable to numerical analysis. Our approach is supported by the (new) tool FOREST for generating the complete prefix and the (existing) tool PEPP for analysing the generated task graph. As a case study, the delay of the first resolution in the root contention phase of the IEEE 1394 serial bus protocol is analysed

A Trial of an Impedance Threshold Device in Out-of-Hospital Cardiac Arrest

Background The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. Methods We compared the use of an active ITD with that of a sham ITD in patients with out-ofhospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability). Results Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, −0.1 percentage points; 95% confidence interval, −1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge. Conclusions Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.

Sendmail Meets Erlang: Experiences Using Erlang for Email Applications

Our software engineering team needed to create a system that moves data from a set of legacy applications with diverse properties to data repositories scattered around the network. This system had to be highly concurrent, straightforward to extend, have high performance, and be coded rapidly by a small development staff. Because of these requirements, the authors embarked upon an experiment to write this application in Erlang. This paper describes what we did, why we did it, and what we learned over the course of our development effort. It is our hope that this chronicle may be useful to others thinking about coding in Erlang for the first time and to the incumbent Erlang community to hear an outsider's perspective on this fine language

One‐year survival after out‐of‐ hospital cardiac arrest: Sex‐based survival analysis in a Canadian population

Abstract Objective We investigated sex differences in 1‐year survival in a cohort of patients who survived out‐of‐hospital cardiac arrest (OHCA) to hospital discharge. We hypothesized that female sex is associated with higher 1‐year posthospital discharge survival. Methods A retrospective analysis of linked data (2011–2017) from clinical databases in British Columbia (BC) was conducted. We used Kaplan–Meier curves, stratified by sex, to display survival up to 1‐year, and the log‐rank test to test for significant sex differences. This was followed by multivariable Cox proportional hazards analysis to investigate the association between sex and 1‐year mortality. The multivariable analysis adjusted for variables known to be associated with survival, including variables related to OHCA characteristics, comorbidities, medical diagnoses, and in‐hospital interventions. Results We included 1278 hospital‐discharge survivors; 284 (22.2%) were female. Females had a lower proportion of OHCA occurring in public locations (25.7% vs. 44.0%, P < 0.001), a lower proportion with a shockable rhythm (57.7% vs. 77.4%, P < 0.001), and fewer hospital‐based acute coronary diagnoses and interventions. One‐year survival for females and males was 90.5% and 92.4%, respectively (log‐rank P = 0.31). Unadjusted (hazard ratio [HR] males vs. females 0.80, 95% confidence interval [CI] 0.51–1.24, P = 0.31) and adjusted (HR males vs. females 1.14, 95% CI 0.72–1.81, P = 0.57) models did not detect differences in 1‐year survival by sex. Conclusion Females have relatively unfavorable prehospital characteristics in OHCA and fewer hospital‐based acute coronary diagnoses and interventions. However, among survivors to hospital discharge, we found no significant difference between males and females in 1‐year survival, even after adjustment

Survival Increases with CPR by Emergency Medical Services before defibrillation of out-of-hospital ventricular fibrillation or ventricular tachycardia: Observations from the Resuscitation Outcomes Consortium

BACKGROUND: Immediate defibrillation is the traditional approach to resuscitation of cardiac arrest due to ventricular fibrillation or tachycardia (VF/VT). Delaying defibrillation to provide chest compressions may improve survival. We examined the effect of the duration of Emergency Medical Services (EMS) cardiopulmonary resuscitation (CPR) prior to first defibrillation on survival in patients with out-of-hospital VF/VT. MATERIALS AND METHODS: From a prospective multi-center observational registry of EMS-treated out-of-hospital cardiac arrest, we identified 1,638 EMS-treated cardiac arrests with first recorded rhythm VF/VT or “shockable” and complete data for analysis. Survival to hospital discharge was determined as a function of EMS CPR duration prior to first shock. RESULTS: Compared to the reference group of first EMS CPR duration ≤ 45 seconds, the odds of survival was greater among patients who received between 46 seconds to 195 seconds of EMS CPR before first shock (46 to 75 seconds odds ratio [OR] 1.15, 95% confidence interval [CI] 0.71-1.87; 76 to 105 seconds, OR 1.37, 95% CI 0.80-2.35; 106 to 135 seconds, OR 1.53, 95% CI 0.96-2.45; 136 to 165 seconds, OR 1.24, 95% CI 0.71-2.15; 166 to 195 seconds, OR 1.47, 95% CI 0.85-2.52). The benefit of EMS CPR before defibrillation was reduced when the duration of CPR exceeded 195 seconds (196 to 225 seconds, OR 0.95, 95% CI 0.47-1.81; 226 to 255 seconds, OR 0.91, 95% CI 0.46-1.79; 256 to 285 seconds, OR 0.46, 95% CI 0.17-1.29; 286 to 315 seconds, OR 1.29, 95% CI 0.59-2.85). An optimal EMS CPR duration was not identified and no duration achieved statistical significance. CONCLUSION: In this observational analysis of VF/VT arrest, between 46 and 195 seconds of EMS CPR prior to defibrillation was weakly associated with improved survival compared to ≤ 45 seconds. Randomized trials are needed to confirm the optimal duration of EMS CPR prior to defibrillation and to assess the impact of first CPR duration on all initial rhythms