Relations between respiratory symptoms and sickness among workers in the animal feed industry

The survey aimed at studying the associations between prevalent respiratory symptoms in an occupational population and sickness absence due to respiratory disorders.

A cross sectional survey among male workers in an animal feed mill was conducted. A total of 303 production workers and 102 office clerks completed a questionnaire on respiratory complaints, smoking habits, and occupational history. The questionnaire was used to identify workers with respiratory symptoms in the past 12 months. During this period all spells of sickness absence were recorded. Causes of sickness were classified in broad categories encompassing respiratory symptoms, influenza, musculoskeletal disorders, and others.

Logistic regression analysis showed that workers with respiratory complaints experienced a higher sickness absence than those without respiratory complaints. Adjusted for age and smoking the odds ratio (OR) for sickness prevalence was 1.9 among office clerks and 2.6 among blue collar workers. Smoking increased the risk on sickness absence with ORs of 2.4 and 1.6, respectively. When restricting the analysis to sickness due to respiratory complaints, subjects with respiratory complaints had significantly higher risks for absence prevalence and absence rate than those without respiratory complaints. There were no differences in sickness absence between workers with asthma like complaints and those with chronic bronchitis like complaints.

The clear associations between respiratory complaints and prevalence and rate of respiratory sickness absence indicate that workers with respiratory complaints are at risk of temporary disability and, thus, may experience a reduced ability to cope with routine activities at work.