Research Plus: August/September 2009

Occupational hearing loss

A review of evidence on interventions to prevent occupational noise exposure and hearing loss has been published by the Cochrane Collaboration. Twenty-one studies met inclusion criteria, though the overall evidence quality was low. There was some evidence – again of low quality – that legislation can reduce workplace noise levels, while the evidence on the effectiveness on hearing protection and hearing loss prevention programmes was contradictory. One long-term study found elevated risks of hearing loss among army recruits due to exposure to impulse noise from shooting, despite the implementation of a hearing-loss prevention programme.

Cochrane Database of Systematic Reviews 2009; 3: article number CD006396. DOI: 10.1002/14651858.CD006396.pub2

No raised mortality risk in shiftworkers

An 11-year study of more than 14,000 rotating shift-workers and 17,000 day workers at the chemical company BASF found marginally lower mortality risks in the former, after accounting for age and job level. There were 414 deaths among the shift workers and 463 among day workers during the study period. Since 1983, the company had been providing additional benefits for shiftworkers, including routine medical examinations and health promotion, and the findings suggest that these may have helped mitigate the long-term health consequences of shiftwork. Shiftworkers had taken part in twice as many medical examinations and twice as many health seminars as day workers, and this greater level of surveillance may explain their raised incidences of diagnosed obesity, chronic obstructive pulmonary disease and other conditions; though the effect of shiftwork itself could not be ruled out.

Scandinavian Journal of Work, Environment and Health 2009; 35(4): 309–318.

Occupational asthma consensus

Consensus guidelines on the diagnosis and management of work-related asthma by the American College of Chest Physicians highlight the importance of individual diagnoses in triggering a workplace evaluation to prevent other cases and, in the case of respiratory sensitisers, the need to implement secondary measures, including medical surveillance. A lack of randomised controlled trials was noted and the evidence is largely drawn from clinical diagnoses rather than cross-sectional or longitudinal cohort studies of exposed workers. There are 12 consensus statements, including that individuals should be screened for possible occupational or work-exacerbated asthma for all new-onset or worsening asthma cases.

Chest 2008; 134; 1S–41S.

Occupational solvent exposure during pregnancy

A population-based study of 3,005 pregnant women found significant raised risks of birth defects from occupational exposure to solvents during pregnancy, with cleaners, healthcare and laboratory workers among those at greatest risk. Solvent exposure was assessed from self-report questionnaires and job-exposure matrices. Just less than one-third of the women had been exposed regularly to at least one product that may contain solvents. According to the job-exposure matrix, 18% of the women were in the medium-exposure category and just over 3% in the high-exposure group. There was a significant association between major non-chromosomal, non-genetic malformations and solvent exposure, with a significant dose–response relationship. There were no associations between solvent exposure and chromosomal and genetic malformations.

Occupational and Environmental Medicine 2009; 66: 456–463.

Shiftwork heart risk?

A systematic review of papers published to May 2008 found only limited evidence of a causal association between shiftwork and ischaemic heart disease (IHD)1. There was only weak or no association of shiftwork with fatal IHD events, though a modest association was observed when fatal and non-fatal events were combined. Selection bias and confounding factors could not be ruled out in most papers.

Mental health RTW

A randomised controlled trial of a guidance-based return-to-work intervention for mental health-related absence found no significant improvement over usual care. A total of 240 police workers on sick leave with mental health problems were randomised to the OH intervention or usual care. Occupational physicians received three days’ training in delivering guidance-based care, based on workplace intervention (eg phased return, workplace adjustments and supervisor contact), graded activity and cognitive behavioural principles. It is suggested that the guidance-based intervention might be more successful in those with minor symptoms, and less effective for those with severe problems.

Journal of Occupational Medicine 2009; 51(3): 305–312.

Thoracic spine pain in working adults

A systematic review of thoracic spine pain (TSP) – or pain in the upper or middle back – among working adults identified 52 studies meeting inclusion criteria. Evidence quality was generally poor, mostly from cross-sectional studies. One-year prevalence estimates varied with professional group, but medians of around 30% suggest that the condition is a significant OH problem. Various individual, physical work and psychosocial work factors were associated with TSP, and these were consistent with evidence on other musculoskeletal disorders.

Journal of Occupational Health 2009; 51(3): 177–192.

Predicting work disability

A systematic review concludes that prognostic factors for work disability are similar for workers with various chronic diseases, enabling high-risk groups to be targeted with a general disability management intervention regardless of their particular diagnoses. Forty-three relevant studies were identified, 32 of high quality. For asthma, rheumatoid arthritis and ischaemic heart disease, the common prognostic factors for work disability were perceived health complaints, disease-related limitation in daily physical activity, heavy manual work and female gender. There were no papers on diabetes, and chronic obstructive pulmonary disease was excluded from the analysis since only one paper met inclusion criteria.

Scandinavian Journal of Work, Environment and Health 2009; 35(4): 264–281.

NICE not so good on OH

Occupational health advice is rarely included in guidelines from the National Institute for Health and Clinical Excellence, highlighting the need for greater participation of OH professionals in guideline development. Thirty-one guidelines were selected for the review because of the impact of the underlying condition on work ability and fitness for work. Twelve of the guidelines (39%) include advice on rehabilitation, while impact on work is mentioned in just seven (22%). Only one in 10 include advice on return to work, while one in five provide no OH advice at all.

Occupational Medicine 2009; 59(5): 353–356.