This study involved cotton textile workers enrolled in a longitudinal study of respiratory disease among textile workers in Shanghai, China. The baseline study in 1981 included 447 cotton textile workers (52 percent female). These represented 90 percent of workers employed more than 2 years and working in eligible jobs. The follow-up survey was performed 5 years later when all but 62 workers (37 female, 25 male) were restudied. Included in the lost worker category are six deceased workers, none of whom died of respiratory disease, and four others who were too ill to participate in the follow-up survey.
The workers studied were employed in the yarn preparation areas of two cotton textile milk in Shanghai, China. Buy allegra online itat on The mills were in the same urban neighborhood, with workers living close by. Both are state-owned and because of the structure of industry in urban China during the time of study (1981 to 1986), worker turnover was low.
Respiratory symptoms were recorded by using a modified and translated American Thoracic Society questionnaire with additional questions on acute work-related responses. The questionnaire was administered by a trained interviewer to each worker upon his or her return to work after a 48-h rest period and before entering the production area. All questionnaires were administered by native speakers using the local dialect. The questionnaire used in the follow-up study was identical to the initial survey questionnaire except for minor modifications regarding acute symptom periodicity, which was a necessary amendment to accommodate the respondents’ unusual work rotation. The workweek was 8 days long, with a change of shift every 2 days and a 2-day break at the end of 6 days of work. Since workers rotated their shift forward on an 8-day cycle, instead of asking a worker to name the day of the week when symptoms were most likely to occur, he or she was asked orally whether symptoms occurred on the first day back after 48 h off, in the middle of the 8-day work cycle, or at the end of the cycle. This modification was incorporated into the written questionnaire at the time of the second survey. This modification, though minor, may have resulted in noncomparable reports of byssinosis in the first and second surveys.