By occupation, the highest number of IPF deaths occurred among males in management (5,715; 14.4% of IPF deaths in males) and among female office and administrative support workers (4,521; 16.1% of IPF deaths in females). The highest significantly elevated PMRs were among male community and social services workers (1.23; 95% CI = 1.14-1.32) and among female farming, fishing, and forestry workers (1.24; 95% CI = 1.01-1.53). Among both male and female workers, the elevated PMRs were found in the health care practitioners and technical occupations (1.13; 95% CI = 1.06-1.21 and 1.21; 95% CI = 1.16-1.27, respectively).
During 2020-2022, 67,843 deaths (39,712 in males and 28,131 in females) among ever-employed persons aged ≥15 years were associated with IPF. Based on an estimate that 21% of IPF deaths might be related to occupational exposures (6), approximately 14,248 deaths (8,340 in males and 5,908 deaths in females) might have been job-related. However, the estimate was based on non-U.S. reports and might not be directly applicable to the U.S. workforce.
Elevated IPF death rates among persons aged ≥75 years and males are consistent with previous reports of increased mortality in these groups (3). In contrast to findings from a previous study, the overall age-adjusted IPF death rate of 7.1 per 100,000 persons over the 3 years of this study was higher than that reported for 2017 (5.3 per 100,000) and the rates in White and non-Hispanic persons (8.2 and 7.7 per 100,00, respectively) were higher than average annual rates reported for 2004-2017 (6.1 and 6.2 per 100,000, respectively) (3). These differences could be partially explained by differences in research methodologies, improved precision in diagnostic criteria, and increasing implementation of recommendations for diagnosing IPF (1), and differences over time in the prevalences of known IPF-associated risk factors (6,7). The decrease in cigarette smoking (7) (known to be associated with IPF) among adults highlights the potentially increasing proportionate role of environmental and occupational exposures in the development of IPF (4-6).
Higher proportions of IPF deaths were observed among ever-employed persons in several industries and occupations. Among both male and female workers, the highest significantly elevated PMRs were found in the public administration, health care and social assistance, and educational services industries as well as in the health care practitioners and technical occupations. Workers in some of these industries and occupations would be anticipated to have frequent exposure to secondhand smoke (8); vapors, gas, dust, and fumes (8); biologic (e.g., bioaerosols in indoor environments) (2,9,10); chemical (e.g., pesticides) (5); and other hazards in the workplace (5-10). However, for some industries and occupations at increased risk, potential sources of increased risk are unclear and might be related to either work exposures or factors not directly related to work that were not fully addressed by the study design.
The findings in this report are subject to at least eight limitations. First, no ICD-10 code is specific to IPF, and IPF might be underreported on death certificates (3). Second, the IPF diagnosis might be affected by access to specialty care and chest computed tomography, both to identify interstitial lung disease and exclude other known causes of interstitial lung disease. However, access to care information was not available, and IPF deaths were not validated using medical records. Third, because of the cross-sectional study design, no temporal relationship between IPF death and work could be measured. Fourth, information on smoking status and workplace exposures are not recorded on death certificates. Therefore, these exposures could not be evaluated for their association with IPF deaths. Fifth, the decedent's usual industry and occupation information reported on the death certificate might not be the industry and occupation associated with IPF deaths. No work histories are recorded on death certificates to evaluate changes in employment. Sixth, multiple comparisons might identify industries and occupations with elevated PMR by chance and thus these might not actually represent occupational risk. Sixth, small sample sizes for some groups resulted in wide PMR CIs. Seventh, application of a population attributable fraction estimate from a different study population to these data is speculative and should be interpreted with caution. Finally, this was an exploratory analysis with no guiding hypotheses; therefore, these findings should be considered hypothesis-generating.
Estimates of elevated IPF mortality among ever-employed persons in certain industries and occupations suggest areas where targeted studies, and processes to identify and control causative workplace exposures according to the applicable standard might be considered. Primary prevention would involve using the hierarchy of controls (elimination, substitution, engineering controls, administrative controls, and personal protective equipment) to reduce or eliminate exposures to potentially causative work hazards.***** In addition, smoke-free workplace policies and tobacco cessation programs can help reduce or eliminate exposure to tobacco smoke. Continued research to confirm these findings, and surveillance including collection of detailed industry and occupational history and etiologic research to further characterize occupational risk factors for IPF, are essential to guide development and implementation of evidence-based interventions and policies to improve workers' health.