An international prospective general population-based study of respiratory work disability

Background: Previous cross-sectional studies have shown that job
change due to breathing problems at the workplace (respiratory work
disability) is common among adults of working age. That research
indicated that occupational exposure to gases, dust and fumes was
associated with job change due to breathing problems, although
causal inferences have been tempered by the cross-sectional nature
of previously available data. There is a need for general
population-based prospective studies to assess the incidence of
respiratory work disability and to delineate better the roles of
potential predictors of respiratory work disability.Methods: A
prospective general population cohort study was performed in 25
centres in 11 European countries and one centre in the USA. A
longitudinal analysis was undertaken of the European Community
Respiratory Health Survey including all participants employed at
any point since the baseline survey, 6659 subjects randomly sampled
and 779 subjects comprising all subjects reporting
physician-diagnosed asthma. The main outcome measure was new-onset
respiratory work disability, defined as a reported job change
during follow-up attributed to breathing problems. Exposure to
dusts (biological or mineral), gases or fumes during follow-up was
recorded using a job-exposure matrix. Cox proportional hazard
regression modelling was used to analyse such exposure as a
predictor of time until job change due to breathing
problems.Results: The incidence rate of respiratory work disability
was 1.2/1000 person-years of observation in the random sample (95%
CI 1.0 to 1.5) and 5.7/1000 person-years in the asthma cohort (95%
CI 4.1 to 7.8). In the random population sample, as well as in the
asthma cohort, high occupational exposure to biological dust,
mineral dust or gases or fumes predicted increased risk of
respiratory work disability. In the random sample, sex was not
associated with increased risk of work disability while, in the
asthma cohort, female sex was associated with an increased
disability risk (hazard ratio 2.8, 95% CI 1.3 to 5.9).Conclusions:
Respiratory work disability is common overall. It is associated
with workplace exposures that could be controlled through
preventive measures.