Codes refer to International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. ALS indicates advanced life support; BLS, basic life support.
a Pickup locations included residence, scene of accident or acute event, skilled nursing facility, and non–skilled nursing facility residential, domiciliary, custodial, or nursing home facility.
b Present on admission status for cardiac arrest is either no or unknown.
c Rural areas are defined as counties that do not meet the metropolitan or micropolitan criteria as defined by the US Bureau of the Census. Metropolitan counties have at least 1 urbanized area of 50 000 or more population, and micropolitan counties have at least 1 urban cluster of at least 10 000 but less than 50 000 population. Both types have adjacent territory that has a high degree of social and economic integration with the core as measured by commuting ties.