Background: The majority of research into health care use of intimate partner violence (IPV) has focused on female victims and primarily their emergency department use. There are limited data on injury-related hospitalization rates for female victims and even less for male victims and perpetrators. The goal of this study was to determine the annualized rates of inpatient injury-related hospitalization among individuals involved as either victims or defendants in IPV.
Methods: This was an observational retrospective study linking data from two Level 1 trauma centers and the county prosecutor's office from 2000 to 2010 in Kalamazoo County, Michigan. (1) Hospital data included injury-related admissions (DRG International Classification of Diseases-9th Rev. codes 800-959.9 excluding 905-909.9). (2) Prosecutor data contained all charging requests for crimes between intimate partners. Annualized rates were calculated for the year before the IPV crime and for the year after, using the following algorithm: (number of hospitalizations) / (total population) × (per 10,000). Confidence intervals and two-sided statistical significance were calculated at the 95% confidence level.
Results: During the study period, 21,179 IPV crimes were committed, involving 12,913 individual defendants and 14,797 victims. There were 30,301 injury-related hospitalizations by this group during this period. Compared with national hospitalization rates of 3.2 per 10,000 people for injury/poisoning (DRG International Classification of Diseases-9th Rev. 800-959.9 and 990-995), IPV victim annual admission rates were 31.9, defendants at 90.4, and bidirectional individuals at 339.1 per 10,000 people, in the 2 years surrounding the crime. Males, regardless of crime role, have higher injury-related hospitalization rates in this period compared with females (male, 115.6; female, 41.8). Males (victims or defendants) and bidirectional participants of either sex had rates that were significantly higher the year after than the year before the crime.
Conclusion: Individuals involved in IPV have a 10-fold higher injury-related hospitalization rate as compared with age-matched national rates. Admission rates vary by sex, crime role, and time frame, with males and bidirectional participants having the highest rates.
Level of evidence: Epidemiological study, level III.