The mailing sample included 3,000 longhaul drivers, 1,104 P&D drivers, 2,638 combination workers, 400 hostlers, 2,258 dock workers, 299 mechanics, 2,256 clerks, 21 janitors, and 10 managers. The overall response rate among workers in the remaining sample was 40.5%, omitting the 632 questionnaires returned either due to an incorrect mailing address or because the employee was deceased. The distribution of job titles, gender, region of residence, and terminal size and location among responders and non-responders was similar (). However, the response rate among Whites (44%) was higher than among Blacks (25%) and Hispanics (28%). Also, responders (mean age=53.0 years) were older than the non-responders (mean age=49.9 years).
Characteristics of Responders and Non-Responders to a Smoking Survey in Trucking Industry Workers
Due to small numbers of females and non-white employees, we restricted this analysis to white males. We further excluded 36 responders with missing information on smoking and 3 janitors and 1 manager. Therefore, there were a total of 3,362 individuals available for analysis.
Characteristics by job title are presented in . Longhaul drivers and clerks were older than other workers. Combination workers and P&D drivers worked in smaller terminals. Education status was similar across groups.
Characteristics of White Men in the Trucking Industry by Job Categories
Age-standardized smoking rates and pack-years smoked were determined by job titles, education, region of residence, terminal size, and terminal location (). Longhaul drivers had the highest prevalence of smoking (18% current smokers and 49% ex-smokers), followed by hostlers (16% current smokers and 49% ex-smokers) and P&D drivers (8% current smokers and 55% ex-smokers). There was only minor variation in never smoking rates between non-clerk job titles. Similarly, although smoking rates were higher among workers in the Midwest, the variation by region of residence was relatively small. Smoking rates were also higher in workers with less than high school education, and varied little by terminal location and size.
Age-Standardized* Smoking Characteristics of White Men in the Trucking Industry
After adjusting for age, education, region of residence, terminal size, and terminal location, the long-haul drivers were more likely to smoke than the workers in other job categories (). However, these differences were small, with the exception of comparison to the clerks. The likelihood of ever smoking increased statistically significantly with increasing age. Workers in the South and West were significantly less likely to be ever smokers as compared with those in the Midwest. Among ever smokers, P&D drivers were significantly more likely to have quit smoking as compared with long-haul drivers, but there were only minor differences among other job titles (). The likelihood of quitting smoking also increased with increasing age. When pack-years was used as the outcome in linear regression models, employment as a longhaul truck driver, increasing age, and terminal location in urban areas were significantly associated with greater lifetime smoking (pack-years) (data not shown).
Unadjusted and Adjusted Likelihood of Smoking among 3,362 White Men in the Trucking Industry
Unadjusted and Adjusted Likelihood of Quitting Smoking (among Ever Smokers) for 2,083 White Men in the Trucking Industry
Similar results were obtained when regression analyses were conducted after excluding people who responded to the shorter personal history questionnaire on postcards (data not shown). Results were also similar if educational status (which had missing values) was dropped from the regression models.