Trends in chronic obstructive pulmonary disease prevalence by occupation in the U.S. workers, 1997-2004

Chronic obstructive pulmonary disease (COPD) was the fourth leading cause of death in the United States in 2004 and is projected to be the third leading cause of death by 2020. To identify occupations with increased trends in COPD prevalence, we examined the 1997–2004 National Health Interview Survey data for employed adults aged 25–75 years. Because cigarette smoking accounts for 80%–85% of all COPD cases we restricted data to never smokers. The annual estimated COPD prevalence was calculated for 41 occupational groups. Sample weights were used to take into account the complex sampling design and non-response. The large sample approximation for the Mann-Kendall statistic was used to test for increasing trend in COPD prevalence (one-sided test).

The overall COPD prevalence among never smokers was 2.8% (95% CI: 2.7–2.9%) and did not change significantly between 1997 (2.8%) and 2004 (2.7%)(p=0.69). The COPD prevalence significantly increased in food service occupations (e.g., kitchen workers, waiters and waitresses) from 2.0% in 1997 to 3.6% in 2004 (p=0.04) and in freight, stock and material handlers occupations (e.g., garbage collectors, material handlers) from 2.3% in 1997 to 3.5% in 2004 (p=0.04).

Further studies may determine specific risk factors for COPD in these two occupational groups. Public health efforts to increase awareness and understanding of COPD should be maintained.