EPIC's main data sets include fatal and hospitalized nonfatal injuries. We identify fatal cases
by searching the death certificates of California residents for any record where the underlying
cause of death was an injury (defined as cases where there was an E-Code as the underlying cause of
death). Similarly, we identify nonfatal injuries by searching hospital discharge data (HDD) for
records where a California resident was hospitalized for an injury (an E-Code was present in the
record). To make sure we do not include an injury event twice, cases that died in the hospital are
removed from our HDD data. Thus our fatal and nonfatal data sets should be mutually exclusive. We
also exclude injuries due to adverse effects of medical encounters and drugs.
Prior to 1999, both fatal and nonfatal causes of injury were coded using ICD-9 E-Codes. Beginning
in 1999, deaths were coded using ICD-10 (V, W, X and Y Codes), while hospitalizations continued to
use ICD-9 E-Codes. This poses problems both in the continuity of death data across time as well as
in comparisons between fatal and nonfatal injuries in 1999 and beyond.