Figure 1: Analysis of potential effect modifiers of the association of occupational lifetime exposure to very loud for ≥15 years and prevalent chronic obstructive pulmonary disease (COPD). The scale of the graph is logarithmic. P-values stand for statistical significance of interaction terms. Models are based on weighted logistic regression to obtain nationally representative estimates. Models are adjusted for gender, age, race/ethnicity (white, black/African American, American Indian/Chinese/Filipino/Asian Indian, and multiple race/other), annual family income (<$35,000, $35,000–74,999, $75,000–99,999, and ≥$100,000), cigarette-smoking status (never smoker, former smoker, current some day smoker, and current every day smoker), smoking other tobacco products, alcohol-drinking status (lifetime abstainer, former drinker, and current drinker), light/moderate physical activity (never, unable to do it, <3 times/week, 4–7 times/week, and >7 times/week), vigorous physical activity (never, unable to do it, <3 times/week, 4–7 times/week, and >7 times/week), body mass index (<25.00 kg/m2, 25.00–29.99 kg/m2, and ≥30.00 kg/m2), asthma and Standard Occupational Classification major occupation group (unless stratified by the respective factor). Some of the covariates are re-categorized when they were tested as effect modifiers. Data source: CDC/NCHS, National Health Interview Survey, 2014.