Care processes and associated long-term outcomes following out-of-hospital cardiac arrest in British Columbia: Novel data linkage and analyses
The overall goal of this project is to identify care gaps for out-of-hospital-cardiac cardiac arrest (OHCA) in BC in order to implement and refine key care processes for OHCA that are important for improving long-term clinical outcomes. The crucial first step is to understand the incidence of OHCA in BC, identify processes of care (including gaps) that currently exist, and determine their association with long-term patient outcomes. Our findings will facilitate improvement of systems of cardiac arrest care elsewhere in Canada and globally.
The specific objectives of the project, broken down into two studies, are to:
Study 1. Examine pre-hospital predictors of long-term outcomes among OHCA patients, including the association of increasing duration of in-field resuscitation with long-term survival. This will allow us to better understand the prevalent use of components of care (bystander CPR, early defibrillation) and their association with long-term survival. The results will help implement public health initiatives for bystander CPR and provide feedback to the pre-hospital providers.
i. Specific Aim 1. To describe baseline clinical characteristics, pre-hospital care processes (bystander CPR, defibrillation) among all OHCA patients stratified by time to return of spontaneous circulation (ROSC) ( 20 mins).
**Hypothesis: We hypothesize that baseline patient characteristics and pre-hospital care will differ among the pre-specified ROSC groups. Specifically, the patients with time to ROSC
ii. Specific Aim 2. To determine the association between increasing time to ROSC ( 20 mins) and 1-year outcomes.
**Hypothesis: We hypothesize that increasing time to ROSC is inversely associated with outcomes, even after adjustment for known confounders.
iii. Specific Aim 3. To determine pre-hospitals predictors of 1-year survival.
**Hypothesis: We hypothesize that younger age, male sex, arrest in a public location, witnessed arrest, bystander CPR, interval from dispatch to EMS arrival, and shockable rhythms will be associated with 1-year survival.
Study 2. Assess temporal trends in long-term survival and readmission among comatose survivors of OHCA. We will describe the baseline clinical characteristics, pre- and in-hospital care processes, and in-hospital outcomes among comatose OHCA patients admitted alive to hospital between 2005 and 2016. We can then assess post-discharge survival and readmission rates. This work will allow us to quantify the burden of OHCA in BC, and describe in-hospital processes (i.e., early coronary angiography and targeted temperature management) that may be associated with improved long-term outcomes.
i. Specific Aim 1. To describe baseline clinical characteristics and pre-hospital care processes among OHCA patients admitted alive to hospital over time from 2005 to 2016.
**Hypothesis: We hypothesize that patient characteristics will not change over time, but there may be improvement in pre-hospital care (shorter time to ROSC, increased rates of bystander CPR).
ii. Specific Aim 2. To compare pre- and in-hospital outcomes and in-hospital interventions among OHCA patients over time from 2005 to 2016.
**Hypothesis: We hypothesize that pre-hospital outcomes will improve over time given improved pre-hospital care and that in-hospital outcomes will also improve due to the improved pre-hospital care and in-hospital care processes.
iii. Specific Aim 3. To describe up to 3 years post-discharge survival and readmission rates among comatose patients with OHCA who survive to hospital admission between 2005 and 2016.
**Hypothesis: We hypothesize that there will be improved long-term survival and reduced rates of readmission over time; however, overall survival will remain poor.