Comorbid Trends in World Trade Center Cough Syndrome and Probable Posttraumatic Stress Disorder in Firefighters

Background: We describe the relationship between World Trade Center (WTC) cough syndrome symptoms, pulmonary function, and symptoms consistent with probable posttraumatic stress disorder (PTSD) in WTC-exposed firefighters in the first year post-September 11, 2001 (baseline), and 3 to 4 years later (follow-up). Methods: Five thousand three hundred sixty-three firefighters completed pulmonary function tests (PFTs) and questionnaires at both times. Relationships among WTC cough syndrome, probable PTSD, and PFTs were analyzed using simple and multivariable models. We also examined the effects of cofactors, including WTC exposure. Results: WTC cough syndrome was found in 1,561 firefighters (29.1%) at baseline and 1,186 (22.1%) at follow-up, including 559 with delayed onset (present only at follow-up). Probable PTSD was found in 458 firefighters (8.5%) at baseline and 548 (10.2%) at follow-up, including 343 with delayed onset. Baseline PTSD symptom counts and probable PTSD were associated with WTC cough syndrome at baseline, at follow-up, and in those with delayed-onset WTC cough syndrome. Similarly, WTC cough syndrome symptom counts and WTC cough syndrome at baseline were associated with probable PTSD at baseline, at follow-up, and in those with delayed-onset probable PTSD. WTC arrival time and work duration were cofactors of both outcomes. A small but consistent association existed between pulmonary function and WTC cough syndrome, but none with PTSD. Conclusions: The study showed a moderate association between WTC cough syndrome and probable PTSD. The presence of one contributed to the likelihood of the other, even after adjustment for shared cofactors such as WTC exposure. CHEST 2011; 140(5):1146-1154