Downloaded from http://oem.bmj.com/ on November 28, 2014 - Published by group.bmj.com

OEM Online First, published on November 27, 2014 as 10.1136/oemed-2014-102639 Commentary

Work-related musculoskeletal disorders: are they truly declining? Sergio Vargas-Prada1,2,3 Occupational hazards have undergone significant changes since the middle of the 20th century. In the past, workers were exposed to serious chemical, physical and biological hazards. However, with the improvement of working conditions and reductions in harmful exposures, much of the morbidity and mortality attributable to those hazards has been reduced in high-income countries. Recently, attention has shifted to other disorders, rarely lethal and not exclusively caused by work, but which account for substantial costs and impact on workers’ well-being.1 Musculoskeletal disorders (MSDs) are a part of these ‘new’ work-related disorders. MSDs are a major cause of disability,2 affecting over 40 million West European workers, with direct costs in Europe estimated at between 0.5 and 2% of gross domestic product.3 Minimising occupational disability attributable to MSDs, and the associated costs, is one of the major challenges in industrialised countries. A growing body of evidence, based largely on administrative data, suggests a decline in the incidence of work-related MSDs over the past decade among people of working age in North America4 and in the Netherlands.5 In this context, the study performed by Mustard et al,6 and reported in this issue of Occupational and Environmental Medicine, used three population-based sources: (1) emergency department records, (2) workers’ compensation claims and (3) samples from different waves of the Canadian health survey, to describe trends in the incidence of work-related MSDs in Ontario, Canada over the period 2004–2011. During the observation period, Mustard et al6 found that the incidence of nontraumatic MSDs, as determined from emergency records, lost-time compensation 1

Center for Research in Occupational Health (CiSAL), Universitat Pompeu Fabra, Barcelona, Spain; 2CIBER Epidemiología y Salud Pública (CIBERESP), Spain; 3 IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain Correspondence to Dr Sergio Vargas-Prada, Center for Research in Occupational Health (CiSAL), Universitat Pompeu Fabra, Calle Dr Aiguader 88, 1ra planta, despacho 171.03, edificio PRBB, Barcelona 08003, Spain; [email protected] Commentary on the paper by Mustard et al., Occup Environ Med, 2014.

claims and responses to the Canadian health surveys, decreased by 16%, 48% and 42%, respectively. Moreover, a large drop of approximately 15% was observed in all the three data sources between 2008 and 2009 during the period of economic recession that followed the onset of the global financial crisis. At first sight this apparent decline in the burden of MSDs linked with work seems important news from a preventive perspective. However, the observed trends might simply reflect a change in people’s propensity to attribute non-traumatic MSD to occupation rather than a true reduction in risk, or they could be driven by other nonmeasured causes. It may seem paradoxical that the decline in incidence of non-traumatic MSDs should accelerate during a time of a severe economic recession when work-related stress increases and employment is more precarious.7 As Mustard et al6 mentioned in their manuscript, it is possible that there was a reduction in exposure to mechanical loading in the workplace, either because of ergonomic improvements, or because the numbers of exposed individuals reduced. However, randomised control trials of ergonomic improvements to prevent musculoskeletal pain have tended to demonstrate an absence of benefits.8 Other possible explanations for the observed decline include the use of ‘case definitions’ based only on biomechanical exposures at work, without consideration of other exposures. Although it is generally agreed that occupational physical activities are risk factors for common MSDs,9 a recent meta-analysis of longitudinal studies has suggested that the risk of low back pain is increased by only about 11% in workers who lift weights of 10 kg by hand.9 This implies that among people exposed to occupational lifting, only a minority of pain cases could be ascribed to their work. Furthermore, exposure to physical activities at the workplace does not adequately explain substantial variations between countries,10 and over time within countries,11 in reported rates of musculoskeletal pain and disability. In consequence, it is possible that the apparent decline of non-traumatic MSD observed by Mustard et al6 might be an artefact of the influence of non-measured variables, such as exposure to psychosocial

aspects of the work environment, changes in individuals’ willingness to attend to emergency departments and differences in pain thresholds, or in beliefs and expectations about pain causation and prognosis. Another possible explanation of this declining trend over time is that use of administrative data from workers’ compensation claims to describe trends in the incidence of work-related MSD results in underestimation of the incidence rates.12 Even in industrialised countries, not all work-related diseases or injuries result in compensation claims; and only employees who receive regular wages, pay taxes and have certain rights, such as access to medical care or sick pay, are covered by workers’ compensation schemes. It is also likely that some workers are less willing to claim for MSDs when they occur because they fear losing their jobs or want to avoid reprisals.13 Improving surveillance of work-related MSD is a priority and, therefore, the study reported by Mustard et al6 is very welcome. In order to understand more fully the apparently declining rates of non-traumatic MSD, we need to carry out repeated controlled epidemiological studies of physical as well as psychosocial risk factors in which overall incidence, relative risks and attributable fractions are assessed for different exposures. Acknowledgements The author is very grateful to Professor Fernando G. Benavides (Universitat Pompeu Fabra) and, Professor David Coggon (University of Southampton) and for their support and assistance during the writing of this commentary. Competing interests None. Provenance and peer review Commissioned; internally peer reviewed. To cite Vargas-Prada S. Occup Environ Med Published Online First: [ please include Day Month Year] doi:10.1136/oemed-2014-102639 Received 4 November 2014 Accepted 13 November 2014

▸ http://dx.doi.org/10.1136/oemed-2014-102442 Occup Environ Med 2014;0:1–2. doi:10.1136/oemed-2014-102639

REFERENCES 1 2

3

Coggon D. Occupational medicine at a turning point. Occup Environ Med 2005;62:281–3. Murray CJ, Vos T, Lozano R, et al. Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: a systematic analysis for the Global Burden of Disease Study 2010. Lancet 2012;380:2197–223. Bevan S, Quadrello T, McGee R, et al. Fit for work? Musculoskeletal disorders in the European workforce. The Work Foundation, 2009. [cited 8 Aug 2013]. http://www.fitforworkeurope.eu/Downloads/

Vargas-Prada S. Occup Environ Med Month 2014 Vol 0 No 0

Copyright Article author (or their employer) 2014. Produced by BMJ Publishing Group Ltd under licence.

1

Downloaded from http://oem.bmj.com/ on November 28, 2014 - Published by group.bmj.com

Commentary

4

5

6

2

Website-Documents/Fit%20for%20Work% 20pan-European%20report.pdf Bhattacharya A. Costs of occupational musculoskeletal disorders (MSDs) in the United States. Int J Ind Ergon 2014;44:448–54. Lambeek LC, van Tulder MW, Swinkels IC, et al. The trend in total cost of back pain in the Netherlands in the period 2002 to 2007. Spine (Phila Pa 1976) 2011;36:1050–8. Mustard CA, Chambers A, Ibrahim S, et al. Time trends in musculoskeletal disorders attributed to work exposures in Ontario using three independent data sources, 2004–2011. Occup Environ Med Published Online First: 13 Oct 2014 doi:10.1136/ oemed-2014-102442

7

8

9

10

Benach J, Vives A, Amable M, et al. Precarious employment: understanding an emerging social determinant of health. Annu Rev Public Health 2014;35:229–53. Driessen MT, Proper KI, van Tulder MW, et al. The effectiveness of physical and organisational ergonomic interventions on low back pain and neck pain: a systematic review. Occup Environ Med 2010;67:277–85. Coenen P, Gouttebarge V, van der Burght AS, et al. The effect of lifting during work on low back pain: a health impact assessment based on a meta-analysis. Occup Environ Med 2014;71:871–7. Coggon D, Ntani G, Palmer KT, et al. Disabling musculoskeletal pain in working populations:

11

12

13

is it the job, the person or the culture? Pain 2013;154:856–3. Gun RT. The incidence and distribution of RSI in South Australia 1980–81 to 1986–87. Med J Aust 1990;153:376–80. Stock S, Nicolakakis N, Raïq H, et al. Underreporting work absences for nontraumatic work-related musculoskeletal disorders to workers’ compensation: results of a 2007–2008 survey of the Québec working population. Am J Public Health 2014;104: e94–e101. Pransky G, Snyder T, Dembe A, et al. Underreporting of work-related disorders in the workplace: a case study and review of the literature. Ergonomics 1999;42:171–82.

Vargas-Prada S. Occup Environ Med Month 2014 Vol 0 No 0

Downloaded from http://oem.bmj.com/ on November 28, 2014 - Published by group.bmj.com

Work-related musculoskeletal disorders: are they truly declining? Sergio Vargas-Prada Occup Environ Med published online November 27, 2014

Updated information and services can be found at: http://oem.bmj.com/content/early/2014/11/27/oemed-2014-102639

These include:

References Email alerting service

This article cites 11 articles, 3 of which you can access for free at: http://oem.bmj.com/content/early/2014/11/27/oemed-2014-102639 #BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.

Notes

To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/

Work-related musculoskeletal disorders: are they truly declining?

Work-related musculoskeletal disorders: are they truly declining? - PDF Download Free
165KB Sizes 0 Downloads 6 Views