We obtained daily deaths caused by CHD during the period of 1
January 2006 to 31 December 2011 from the Center for Disease
Control and Prevention. Deaths primarily due to CHD were identified
by codes I20eI25, according to the Tenth Revision of the International
Classification of Disease with codes I20eI25. In
Shanghai, death certificates were completed at the time of death
either by community doctors for deaths at home, or by hospital
doctors for deaths at hospitals. The coding was determined by
physicians according to patients' symptoms, inquiries, complaints,
and results of a medical inspection or descriptions from decedents'
relatives. According to death certificates, OHCD refers to deaths
occurring outside of a hospital (e.g., at home, or in a public place,
ambulance car or emergency room). Individuals who died in an
emergency room almost had experienced a heart attack outside of
the hospital, and were thus considered to be OHCDs. IHCDs refer to
deaths occurring in a hospital