Probable posttraumatic stress disorder related to the September 11, 2001, terrorist attacks and self‐inflicted injury–related hospitalizations and emergency department visits

Self-inflicted injury is a known risk factor for suicide. Previous studies have reported associations between posttraumatic stress disorder (PTSD) and self-inflicted injury; however, this association has not been widely studied among disaster-exposed populations. Among 50,386 enrollees in the World Trade Center Health Registry, a cohort of individuals exposed to the September 11, 2001, attacks in New York City (9/11), we examined longitudinal associations between probable 9/11-related PTSD and hospitalizations and emergency department (ED) visits for self-inflicted injuries that occurred between study enrollment (2003-2004) and 2015. Time-dependent Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals (CIs) for associations of time-varying probable 9/11-related PTSD and self-inflicted injury, adjusting for sociodemographic and pre-9/11 mental health symptoms. At study enrollment, 11.0% of enrollees had probable PTSD. Over a median follow-up period of 11.2 years, a total of 171 hospitalizations/ED visits for self-inflicted injury occurred among 146 enrollees. When comparing individuals with probable PTSD to those without probable PTSD, the multivariable-adjusted hazard ratio for self-inflicted injury was 2.45, 95% CI [1.63, 3.66]. Evidence of effect modification by age group was not observed. Our findings suggest that surveillance for PTSD among disaster-exposed populations may help identify individuals at high risk of self-inflicted injury who could benefit from targeted interventions.