Dispatcher-assisted bystander cardiopulmonary resuscitation in a metropolitan city: a before-after population-based study.

<p><b>BACKGROUND: </b>The goal of this study was to determine the effects of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-CPR) on outcomes of out-of-hospital cardiac arrest (OHCA).</p><p><b>METHODS: </b>All EMS in a metropolitan city with a population of 10 million are dispatched by a single, centralized, and physician-supervised center. Data on patients with adult OHCA with cardiac etiology were collected from the dispatch center registry and from EMS run sheets and hospital medical record review from 2009 to 2011. A standardized DA-CPR protocol (aligned with the 2010 AHA guidelines) we implemented as an intervention in January 2011. The end points were survival to discharge, good neurological outcome, and bystander CPR rate. Multivariate logistic analysis was used to compare between intervention group (2011) and historical control group (2009-2010).</p><p><b>RESULTS: </b>Of 8.144 eligible patients, bystander CPR was performed for the patients in 5.7% (148/2600) of cases in 2009, 6.7% (190/2857) in 2010, and 12.4% (334/2686) in 2011 (p&lt;0.001). The survival to discharge rates was 7.1% (2009), 7.1% (2010), and 9.4% (2011) (p=0.001). Good neurological outcomes occurred in 2.1% (2009), 2.0% (2010), and 3.6% (2011) of cases (p&lt;0.001). The adjusted ORs (95% CIs) for survival to discharge compared with 2009 were 1.33 (1.07-1.66) in 2011 and 1.12 (0.89-1.41) in 2010. The adjusted ORs (95% CIs) for good neurological outcomes were 1.67 (1.13-2.45) in 2011 and 1.13 (0.74-1.72) in 2010.</p><p><b>CONCLUSIONS: </b>An EMS intervention using the DA-CPR protocol was associated with a significant increase in bystander CPR and an improved survival and neurologic outcome after OHCA.</p>