Objective: To identify US counties (1) that had either significantly high or significantly low firearm homicide rates among black males 15 through 19 years of age in 1983 through 1985 and in 1987 through 1989, and/or (2) that experienced a significant increase in the firearm homicide rate between 1983 through 1985 and 1987 through 1989.
Design: Using the Compressed Mortality File, a county-level mortality and population database maintained by the National Center for Health Statistics, Centers for Disease Control, Hyattsville, Md, county-level firearm homicide rates are analyzed.
Setting: Eighty counties with a population of at least 10,000 black males 15 through 19 years of age in 1987 through 1989.
Subjects: Black males 15 through 19 years of age whose underlying cause of death was classified as firearm homicide (E965.0 through E965.4, or E970) in the ICD-9 (International Statistical Classification of Diseases, Injuries, and Causes of Death, Ninth Revision).
Main outcome measure: County-specific firearm homicide rate.
Results: In 1983 through 1985 and in 1987 through 1989, seven and 13 counties, respectively, were identified that had significantly high firearm homicide rates. Firearm homicide rates were significantly high in both time periods in the following counties: Los Angeles, California; Wayne, Michigan; Kings, New York; St Louis City, Missouri; and Baltimore City, Maryland. Firearm homicide rates increased significantly between 1983 through 1985 and 1987 through 1989 in 34 of the 80 counties. Twenty counties had significantly low rates in both time periods. Several counties with low rates in 1983 through 1985 experienced significant increases and by 1987 through 1989 were among those with high rates.
Conclusions: Surveillance of firearm homicide rates at the county levels in counties with high and with low rates is a necessary first step in the development of successful violence prevention programs. Those counties where rates are high and increasing are the counties that are in greatest need for intervention strategies. Knowledge of the incidence of nonfatal firearm injuries is also needed.