Reducing hospitalizations due to violent injury in San Francisco: The importance of housing status and mental health services

Introduction: Prior analysis has demonstrated high rates of undiagnosed or untreated mental health issues in those who have been involved in violence. 

Methods:  The records of a random sample of those admitted for violent injury from our Level-1 trauma center in 2011 were reviewed (n=380). The 10-year recidivism rate was established; healthcare utilization and cost data was collected. Bivariate and multivariate analysis were performed. Cost was estimated using established methodology.

Results: A total of 701 violent episodes were represented in the cohort of 380 patients. Males comprised 89% of the cohort; 38% were black.  The cohort had a 3.9% hospital mortality rate. Nearly half (48%) of the sample had ever been homeless and 42% had engaged with Safety-Net mental health services (MHS). Those who had ever been homeless were more likely to be a recidivist of violent injury (Risk Ratio: 1.7, p<.0001) and far more likely to have a mental health diagnosis (p<0.001). 51% of the cohort was uninsured, 39% on a safety net plan (Medicare/Medicaid) and 9.9% was privately insured. Patients who had engaged in MHS were less likely to be recidivists in both the homeless (44% vs 61%) and housed (30% vs 61%) subsets (p<0.05).  The yearly cost difference associated with participation in MHS in uninsured homeless violent injury patients is estimated at $796,612.

Conclusion: We found a strong association between access to outpatient MHS and decreased injury recidivism in both the homeless and housed populations. This may represent a potential intervention for violent injury recidivism.