Association between Intimate Partner Violence and Hospital-Based Healthcare Utilization: A Matched Cohort Analysis

Intimate partner violence (IPV) is a serious public health issue associated with increased healthcare utilization and worse outcomes. The majority of IPV research is conducted in emergency and outpatient populations.

To investigate how IPV affects hospitalization rates and outcomes in adult patients.

Matched cohort study. Five hospitals in an integrated, academic healthcare system in the Northeast.

Patients with at least one hospitalization from October 1, 2016-October 1, 2019. IPV-exposed patients responded "yes" to a standardized abuse screen, received a referral to the hospital IPV program, or had a diagnostic billing code for IPV. Control patients responded "no" to the abuse screen.

The primary outcome was hospitalization rate per patient-year. Secondary outcomes included mean length of stay (LOS), self-directed discharge, restraint use, and measures of healthcare utilization and in-hospital morbidity. Each exposed patient was matched to three controls on sex, location of abuse screening, and age within 5 years. We performed multivariable regression analysis and staged mediator analyses for mental health diagnoses, substance use diagnoses, and both.

Our cohort consisted of 2095 IPV-exposed patients and 6285 matched controls (76% female, mean age 52). IPV-exposed patients had significantly higher hospitalization rates compared to unexposed patients (1.12 hospitalizations/year vs 0.74 hospitalizations/year, aIRR 1.51 [1.44, 1.58], p < 0.01). IPV-exposed patients also had significantly longer LOS; higher rates of three or more consults, restraint use, single-dose antipsychotic use, self-directed discharge, and higher pain scores; and lower rates of procedures. Staged mediation analysis revealed 9% mediation of primary outcome by mental health diagnoses, 15% by substance use diagnoses, and 19% by both.

IPV exposure is associated with increased hospitalization rates and greater in-hospital utilization and morbidity. Our findings underscore the importance of IPV detection and intervention efforts in hospitals to improve care of this vulnerable population.