Surveillance for homicide among intimate partners--United States, 1981-1998

A substantial percentage of all homicides in the United States are committed by intimate partners of the victims. Among females, approximately 1 in 3 homicides are intimate partner homicides (IPHs). Intimate partner homicides cannot be tracked by using death certificates because death certificates do not record the victim's relationship to the perpetrator.

This report summarizes information regarding IPHs that occurred in the United States during 1981-1998.

This report is based on Supplemental Homicide Reports (SHRs) collected by the Federal Bureau of Investigation (FBI) as part of their Uniform Crime Reporting System. SHRs are filed voluntarily by police departments for homicides occurring within their jurisdiction. SHRs include demographic variables regarding victims and perpetrators, their relationship, and weapon(s) used. Data from the SHR file were weighted by comparison with homicide data from death certificates to compensate for underreporting. IPHs were restricted to victims aged > or = 10 years.

The risk for death from IPH among males was 0.62 times the risk among females. However, the rate among black males was 1.16 times the rate among black females. Among racial groups, rates among blacks were highest, and the rates among Asian or Pacific Islanders were lowest. Rates were highest among females aged 20-49 years and among males aged 30-59 years. During the study period, rates among white females decreased 23%, and rates among white males decreased 61.9%. Rates among black females decreased 47.6%, and rates among black males decreased 76.4%. Highest rates occurred in the southern and western states among both white and black females. A graded increase in IPH risk occurred with community population size. Approximately 50% of IPHs were committed by legal spouses and 33% by boyfriends or girlfriends for both male and female victims. IPH rates were less than expected during the months of January, October, and November.

Although total homicide rates have fluctuated during 1981-1998, IPH rates have decreased steadily during this period, and among certain subpopulations, the decrease has been substantial. Decreases are temporally associated with the introduction of social programs and legal measures to curb intimate partner violence, but a causal relationship has not been established. Likewise, no confirmed explanation exists for the greater decrease in rates among males compared with rates among females. The differences in IPH rates by race indicate that economic, social, and cultural factors are involved. The analysis by community population size and state demonstrates that regional sociocultural differences might be involved also. Access to firearms might be a key factor in both male and female IPHs.

The descriptive epidemiology of IPH is changing rapidly and should continue to be monitored. Understanding the reasons forthe recent decreases in IPHs might help identify methods for primary and secondary prevention and further reduce IPH rates.