Abstract
BACKGROUND: 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. OBJECTIVE: To investigate how IPV affects hospitalization rates and outcomes in adult patients. DESIGN: Matched cohort study. Five hospitals in an integrated, academic healthcare system in the Northeast. PARTICIPANTS: 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. MAIN MEASURES: 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. KEY RESULTS: 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. CONCLUSIONS: 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.