Overview of the shenzhen emergency medical service call pattern.

Background: In Shenzhen, the Emergency Medical Service (EMS) system has been in service since 1997. This study aims to examine the operation of Shenzhen 120 EMS center and to identify the reasons of calling EMS.

Methods: In this retrospective quantitative descriptive study, the data from the Shenzhen 120 EMS registry in 2011 were analyzed.