Respiratory
Heterogeneity in World Trade Center-related cough: a 24-year sequence analysis approach Alexandra Mueller* Alexandra Mueller Mueller Mueller Mueller Montefiore Medical Center/FDNY
Introduction: Nearly 25 years after the World Trade Center (WTC) disaster on 9/11/2001, WTC Cough directly following seems to mostly resolve within a few years. Based on 2024 reports, cough point prevalence is ~8%. However, analyzing this group as a whole may obscure heterogeneity in the timing or persistence of cough outcomes. We characterized underlying patterns of cough trajectories in New York City Fire Department (FDNY) WTC-exposed rescue/recovery workers over 24 years.
Methods: We studied FDNY WTC-exposed responders who completed ≥5 health surveys between 10/2001-9/10/2025, with the first occurring within 1 year of 9/11. Participants answered if they had a cough (present/absent) in the past year unrelated to illness. Sequence analysis characterized longitudinal sequences of cough trajectories. Missing responses were retained. Hierarchical cluster analysis grouped participants with similar trajectories. We measured forced expiratory volume in 1 second % predicted (FEV1%). Diagnoses were obtained from medical records.
Results: In 8,283 people, we identified that 4 distinct clusters best fit the data: Persistent Cough (PC) (14%), Resolved Cough (RC) (40%), No Cough (NC) (35%), and Incomplete Follow-up (IFU) (11%). PC reported cough frequently throughout the study period; RC reported cough at their first exams in 2001-2002 but not often later; NC rarely reported cough; IFU was characterized by shorter follow-up time. 82% of PC had gastroesophageal reflux disease (GERD) compared with 62% of RC and 53% of NC. PC and RC had similar FEV1%, WTC arrival times, BMI, smoking status, and age.
Conclusion: Sequence analysis revealed four distinct cough trajectories over 23 years. While most had no or resolved cough, 14% had persistent cough. Similar WTC exposure timing, smoking, BMI, and, importantly, FEV1% across PC and RC clusters suggest that persistent cough in this cohort may be more related to comorbidities, including GERD which has a known association with chronic cough.
