Prospective risk factors for traumatic event reexposure in community syringe exchange participants.

Background: Traumatic event reexposure in injecting drug users is associated with increased drug use and potential for psychiatric symptoms. This is the first study to examine fixed and time-varying factors that are prospectively associated with new traumatic event reexposure in injecting drug users.

Methods: Injecting drug users registered in a syringe exchange program were enrolled in a 16-month parent study comparing strategies to increase drug abuse treatment enrollment. Participants (N=162) completed baseline measures of demographics, psychiatric treatment history, and lifetime traumatic event exposure. Monthly follow-ups assessed past-month traumatic event exposure, days of heroin and cocaine use, criminal activity, and drug abuse treatment participation. Generalized estimating equations models tested the influence of fixed baseline and time-varying factors on traumatic event reexposure in the same month, the following month, and two months later.

Results: Significant fixed risk factors for traumatic event reexposure include female gender and past psychiatric treatment. In addition, each past traumatic event exposure was associated with an increased likelihood of reexposure. After accounting for all other factors, each day of cocaine use was associated with a small but persistent increased risk of traumatic event reexposure. Reexposure to a traumatic event in the prior month more than doubled the risk of subsequent reexposure.

Conclusions: Injecting drug users experience a pattern in which drug use is associated with increased risk of subsequent traumatic event reexposure, and traumatic event reexposure is associated with further drug use and continued reexposure. Implications for addressing these concerns in injecting drug users are presented.