Longitudinal determinants of posttraumatic stress in a population-based cohort study.

BACKGROUND Posttraumatic stress disorder is a prevalent and disabling psychologic pathology. Longitudinal research on the predictors of posttraumatic stress symptomatology is limited. METHODS We recruited 2752 participants to a prospective, population-based cohort study by conducting a telephone survey of adult residents of the New York City metropolitan area in 2002; participants completed 3 follow-up interviews over a 30-month period. Censoring weights were estimated to account for potential bias. We used generalized estimating equation logistic regression models with bootstrapped confidence intervals to assess the predictors of posttraumatic stress over time in multivariable models. RESULTS Predictors of posttraumatic stress over time included ongoing stressors (odds ratio [OR] = 1.91 per 1 unit increase in number of stressors, [95% confidence interval = 1.55-2.36]) and traumatic events (OR = 1.92 per 1 unit increase in number of traumatic events [CI = 1.71-2.22]), social support (compared with high levels, OR = 1.71 for medium [1.09-2.52]; OR = 1.57 for low [1.08-2.35]), low income (OR = 0.87 per $10,000 increase [0.81-0.92]), female sex (1.60 [1.11-2.23]), and Latino ethnicity (compared with white, OR = 1.74 [1.05-2.97]). CONCLUSIONS These findings suggest that ongoing stressors play a central role in explaining the trajectory of posttraumatic stress over time, and that factors beyond the experience of stressors and traumas may account for sex and ethnic differences in posttraumatic stress risk. Interventions that focus on reducing ongoing adversity may help mitigate the consequences of traumatic events.