Post–September 11, 2001, Incidence of Systemic Autoimmune Diseases in World Trade Center–Exposed Firefighters and Emergency Medical Service Workers

Abstract

Objective To estimate the incidence of selected systemic autoimmune diseases (SAIDs) in approximately 14,000 male rescue/recovery workers enrolled in the Fire Department of the City of New York (FDNY) World Trade Center (WTC) Health Program and to compare FDNY incidence to rates from demographically similar men in the Rochester Epidemiology Project (REP), a population-based database in Olmsted County, Minnesota. Patients and Methods We calculated incidence for specific SAIDs (rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, and others) and combined SAIDs diagnosed from September 12, 2001, through September 11, 2014, and generated expected sex- and age-specific rates based on REP rates. Rates were stratified by level of WTC exposure (higher vs lower). Standardized incidence ratios (SIRs), which are the ratios of the observed number of cases in the FDNY group to the expected number of cases based on REP rates, and 95% CIs were calculated. Results We identified 97 SAID cases. Overall, FDNY rates were not significantly different from expected rates (SIR, 0.97; 95% CI, 0.77–1.21). However, the lower WTC exposure group had 9.9 fewer cases than expected, whereas the higher WTC exposure group had 7.7 excess cases. Conclusion Most studies indicate that the healthy worker effect reduces the association between exposure and outcome by about 20%, which we observed in the lower WTC exposure group. Overall rates masked differences in incidence by level of WTC exposure, especially because the higher WTC exposure group was relatively small. Continued surveillance for early detection of SAIDs in high WTC exposure populations is required to identify and treat exposure-related adverse effects.

FDNY and 9/11: Clinical services and health outcomes in World Trade Center‐exposed firefighters and EMS workers from 2001 to 2016

“…For that reason, many of our analyses have used external comparison groups including the general U.S. population, REP participants [Webber et al, ], and more recently, NIOSH 3‐cities firefighter cohort [Moir et al, ]. Because FDNY‐WTC rescue/recovery workers had stringent pre‐hire health requirements, and were routinely screened post‐hire, previous comparisons with the general U.S. male population and REP participants may be limited by dissimilar health status at baseline [Zeig‐Owens et al, ; Webber et al, ]. The NIOSH 3‐cities firefighter cohort, a group more similar to FDNY WTC firefighters, is limited by data that ends in 2009 [Daniels et al, ; Moir et al, ] and an absence of data on smoking status and other potential confounders.…”

“…In a later study, we identified 63 rheumatologist‐confirmed cases of SAIDs, but also included 34 additional “probable” cases, that, according to two rheumatologists, likely had SAIDs, but lacked adequate documentation [Webber et al, ]. Although we found that overall SAIDs rates were not significantly different from expected rates (SIR: 0.97; 95%CI: 0.77–1.21), based on comparison with incident cases from Rochester Epidemiology Project (REP) participants, highly WTC‐exposed FDNY rescue/recovery workers had an excess of 7.7 cases of SAIDs, while lesser‐exposed workers had 9.9 fewer cases than expected.…”

World Trade Center Health Program: First Decade of Research

“…Although individually rare, SAIDs substantially impact mortality and morbidity and together are a leading cause of death among women aged < 65 years [ 127 ]. Recent studies have suggested associations between SAIDs, PTSD, and WTC-exposure [ 128 , 129 , 130 ]. A case-control study of responding firefighters found SAIDs incidence increased by 13% (OR = 1.13, 95% CI: 1.02, 1.26) for each additional month worked at the WTC site [ 130 ].…”

Understanding the role of environmental factors in the development of systemic lupus erythematosus

“…Acute, high-level exposure to dusts generated in the World Trade Center Disaster has been linked to a variety of respiratory symptoms and diseases in rescue and clean-up workers [43]. Although there were few SLE cases, rates of composite systemic autoimmune diseases were elevated in workers exposed to the highest levels.…”