Assembling the Career Firefighter Health Study cohort: A methods overview

Abstract

Background: Studies of World Trade Center (WTC)-exposed rescue/recovery workers report the increased occurrence of health conditions after work at the WTC disaster site. However, the extent to which these associations are due to WTC exposure is unclear, in part due to the lack of suitable comparison groups. Accordingly, we identified a previously assembled National Institute for Occupational Safety and Health (NIOSH) cohort of career firefighters from three US cities (n = 29,992). Here, we document the challenges in establishing this non-WTC-exposed firefighter cohort for the goal of tracking and comparing cancer and chronic health conditions in WTC-exposed and non-WTC-exposed firefighters.Methods: Follow-up process included institutional review board applications, data use agreements, state cancer registry linkages and vital status determination for the NIOSH firefighter cohort. After completion of these steps, we undertook outreach to the three original city fire departments and union officials, before contact tracing and direct recruitment of 14,566 living firefighters to complete a confidential health survey. We staggered recruitment efforts by the city, using letters, postcards, emails, videos, and telephone outreach. Participants who completed the survey received $10.Results: A total of 4962 of 14,566 alive firefighters responded to the baseline survey (34.1% response rate). Respondents were older and more likely to be non-Hispanic white than nonrespondents. Conclusions:We provide an overview of the process for the first survey to collect information on physical and mental health conditions among US firefighters. The data collected will have an important impact on studies of WTC rescue/recovery work, firefighting, and related health conditions.

Comparing self‐reported obstructive airway disease in firefighters with and without World Trade Center exposure

“…Instead, the non‐WTC‐exposed firefighter comparison population was comprised of career firefighters from fire departments in Chicago, Philadelphia, and San Francisco, whose roster information was originally obtained by the National Institute for Occupational Safety and Health 22 . A subset of this population was alive and eligible for follow‐up, as described elsewhere 21 . A subset of eligible non‐FDNY members completed a self‐administered health questionnaire similar to the FDNY health monitoring questionnaire by May 26, 2021 ( n = 3346).…”

“…A subset of eligible non‐FDNY members completed a self‐administered health questionnaire similar to the FDNY health monitoring questionnaire by May 26, 2021 ( n = 3346). Respondents were demographically similar to nonrespondents 21 . We excluded 208 female firefighters and 283 firefighters who reported WTC exposure.…”

“…Respondents were demographically similar to nonrespondents. 21 We excluded 208 female firefighters and 283 firefighters who reported WTC exposure.…”

“…22 A subset of this population was alive and eligible for follow-up, as described elsewhere. 21 A subset of eligible non-FDNY members completed a self-administered health questionnaire similar to the FDNY health monitoring questionnaire by May 26, 2021 (n = 3346). Respondents were demographically similar to nonrespondents.…”

“…Since WTC‐exposed firefighters have also encountered more typical firefighting hazards during their careers, current WTC research has not adequately controlled for the potentially confounding variable of the firefighting occupation 15,17–20 . The present study was undertaken to assess whether WTC‐exposed firefighters have a greater risk of self‐reported OAD diagnoses compared with non‐WTC‐exposed firefighters using data from the Career Firefighter Health Study (CFHS) cohort, which is comprised of career firefighters from the New York City, Chicago, Philadelphia, and San Francisco Fire Departments 21 . Additionally, to provide context for our findings, firefighters from each group (WTC‐exposed and non‐WTC‐exposed) were compared with the general population using data from the National Health Interview Survey (NHIS).…”