Dear Editor

A recent article by Daniels [1] in this journal presented occupational stress data from the 15 European Union (EU) countries.

Cross- national comparisons contribute to our scientific understanding of how and why health-related indicators (i.e. stress) are unequally distributed across countries and provide clues and guidelines for researchers, policy makers and trade unions at the EU level. However, we are concerned the data’s strengths and limitations are not explained appropriately to inform the policy debate. Specifically we have four concerns.

Our first concern is related to sample selection. The data were drawn from the Third European Survey on Working Conditions (ESWC) conducted in 2000.[2] The sampling strategy was designed to obtain nationally representative samples of the total active population, including non- Europeans if they could be interviewed in the national language of the country where they worked. Daniels asserted occupational stress is socially constructed and thus used nationality to obtain a more homogeneous sample. However, removing workers who may be experiencing the greatest stress and hazardous working conditions from the sample may represent a severe selection bias.[3]

The inflow of foreign workers (especially the so called low-skilled immigrants) to the EU advanced industrial countries is increasing.[4] Immigrant workers are becoming a significant part of the active EU population and are likely to rise sharply with the addition of the ten new EU countries.[5,6] Compared to native workers, non-EU nationals have greater problems obtaining jobs.[7] They may obtain employment in contractual jobs where exposure to work-related stressors is high.[8] It is plausible foreign workers are more frequently employed in ‘bad’ jobs exposed to more hazardous work environments.[9]

Furthermore, because of the ambiguity of the statement "individuals who were working in a different country as their nationality" (i.e. immigrants) – it is unclear who is being excluded and whether the issue of the social construction of stress can be redressed through the exclusion. The ESWC does not identify whether a person was born in the country of present nationality, lived in the same country since birth with or without the nationality of that country, or lived, or was born, elsewhere before coming to the country of present nationality. Neither does the ESWC provide data on when, in a life course perspective, the arrival of a person to a country occurred which may be relevant for assimilating social constructs by an individual. All these factors can influence health variability and without such detailed data deductions based only on a person’s nationality seems uncertain.

Second, information bias can affect the results.[3] By means of principal component analyses, Daniels grouped a number of items (stress, anxiety, irritability, sleeping problems, stomach ache, headache, or overall fatigue) to create an "index of perceived risk from occupational stress". However, two methodological issues have to be considered. First, if, as Daniels argues, stress is socially constructed and thereby biased by nationality, how can be the occupational stress index be created using the total sample instead of only those workers who were working in the same country as their nationality. We would agree this was the appropriate approach if Daniels would not have argued for a social construction of stress. Second, in the ESWC questionnaire, a filter question existed before the selection of the symptoms that the author did not mention. Only after replying that their work affected their health, which some 60% of the workers did, could participants endorse any of 22 symptoms.[2] In analyses using the same data set,[8,10,11] we found differences in various health-related outcomes (stress, overall fatigue, job dissatisfaction and sickness absence) by country, type of employment, and gender.[12] So, grouping items without exploring individual symptom variation might hide important differences.

Third, in the discussion section, Daniels stated that according to his findings, compared to workers in higher ranked countries, British workers and workers in other lower ranked countries may be less likely to attribute minor or non-specific psychosomatic symptoms to work (or might attribute them erroneously to other life domains) when consulting with health practitioners. We are aware of no data to support such an assertion. Hence, the findings do not support this conclusion, so we suggest prudence in the application of these results to policy and practice decisions.

Fourth, Daniels ranked the EU countries investigated according to the number of stress related symptoms attributed to work. From these differences Daniels’s made inferences about how sociocultural factors and the role of the media can affect health perceptions. Given the concerns expressed above abut selection and information bias we wonder how the results led to these inferences. Furthermore, although Daniels recognised that these processes may not apply to other EU countries, he focused almost the entire discussion section on the UK, building an idiosyncratic and ad hoc explanation for the UK that seems unsupported by the research. A way to facilitate more systematic analyses could be by classifying the countries according to certain common characteristics. In social and policy research, different typologies have been proposed. For instance, Esping-Andersen’s typology has proven to be useful in comparing welfare states and may be helpful in the present study’s context.[13]

Moreover, the Daniels’ ranking is very different, and in some cases completely inverse, than the one obtained by us when analyzing sickness absence data from the same survey.[14] Among other factors that could explain this divergence, it has to be considered that different outcomes could present different between-countries distributions. Compared to Daniels’ occupational stress index, sickness absence is recognised as a public health surveillance measure indicating countries economic performance.[15] Rankings are an important tool scientists can use to communicate with policy makers. The ESWC provides a unique data source for scientists. Differences between our work and Daniels illustrates the need to develop mechanisms to enable researchers using the ESWC to share results prior to publication.

Finally, we do understand that the space available for short papers limits the author’s possibility to explain in detail all relevant issues. However, we think that authors should give the reader as much information as needed to judge the results validity.

References

1.Daniels K. Perceived risk from occupational stress: a survey of 15 European countries. Occup Environ Med 2004; 61: 467-70.

2.Paoli P, Merllié D. Third European Survey on Working Conditions 2000. Dublin: European Foundation for the Improvement of Living and Working Conditions Luxembourg: Office for Official Publication of the European Communities, 2001.

3.Szklo M, Nieto FJ. Understanding lack of validity: Bias. In: Szklo M, Nieto FJ. Epidemiology. Beyond the Basics. Gaithersburg: Aspen Publishers, Inc., 2000; 125-76.

4.Lowell BL, Kemper Y. Transatlantic Roundtable on Low-skilled Migration in the Twenty-first Century: Prospects and Policies. International Migration 2004;42(1):117-40.

5.Hilderink H, van der Gaag N, van Wissen L, Jennissen R, Román A, Salt J, Clarke J, Pinkerton C. Analysis and forecasting of international migration by major groups - Part III. Luxembourg: Office for Official Publication of the European Communities, 2003.

6.Angrist JD, Kugler AD. Protective or counter-productive? Labour market institutions and the effect of immigration on EU natives. Economic Journal 2003; 113(488): F302-F331.

7.Thorogood D, Winqvist K. Women and men migrating to and from the European Union. Statistics in focus 2/2003. European Communities, 2003.

8.Wrench J. Preventing Racism at the Workplace. A summary. European Foundation for the Improvement of Living and Working Conditions. Luxembourg: Office for Official Publications of the European Communities, 1996.

9.Benach J, Gimeno D, Benavides FG. Employment status and health. Dublin: European Foundation for the Improvement of Living and Working Conditions. Luxembourg: Office for Official Publication of the European Communities, 2002.

10.Benach J, Gimeno D, Benavides FG, Martínez JM, Torné MM. Types of employment and health in the European Union: changes from 1995 to 2000. Eur J Public Health (in press).

11.Gimeno D, Benavides FG, Amick III BC, Benach J, Martínez JM. Psychosocial factors and work-related sickness absence among permanent and non-permanent employment. J Epidemiol Community Health (in press).

12.Karjalainen A (Coordinator). Work and health in the EU. A statistical portrait. Data 1994–2002. Luxembourg: Office for Official Publication of the European Communities, 2004.

13.Esping-Andersen G. The three worlds of welfare capitalism. Princeton (NJ): Princeton University Press, 1990.

14.Gimeno D, Benavides FG, Benach J, Amick III BC. Distribution of sickness absence in the European Union countries Occup Environ Med (in press).

15.Kivimaki M, Head J, Ferrie JE, Shipley MJ, Vahtera J, Marmot MG. Sickness absence as a global measure of health: evidence from mortality in the Whitehall II prospective cohort study. BMJ 2003 16;327:364-9.

In a recent short report, a summary of the results of a workplace based colorectal tumour-screening programme in UK was given.[1]

During 2001-02 we organised a similar programme within BASF's – the world's largest chemical company – Ludwigshafen/Germany site. Our findings were published in a German language paper.[2] Our target group included all 13 265 actively working employees aged 45 years or above. Those expressing interest were given a standardised questionnaire concerning risk factors for colorectal cancer and a test for occult faecal blood (FOBT). If the test was positive and/or a positive answer was given to the question on blood in the stool or on a positive family history, colonoscopy – to be arranged via the general practitioner – was advised, in line with the recommendations of the German Society of Digestive and Metabolic Diseases.

Finally, 3732 employees (337 women, 3395 men; mean age 52 years) had completed the questionnaire and the FOBT results were available (28 % of the target group). Colonoscopy was recommended to 688 employees, 323 of whom (47 %) underwent the investigation. Nine of the subjects already had manifest cancer, six of them in the early stage T1 or T2. Adenomatous polyps were found in an additional 61 and subsequently excised.

Cost-benefit calculations were done in a twofold manner: at company level and at public-health system level. The financial cost of screening at company level was € 108 000 (testing kits plus office materials € 6000, staff costs € 102 000). Based on the employer's obligation in Germany to compensate disease-related lost work time during the first six weeks a benefit due to avoided lost work time was calculated to be 1 110 000 (cost -benefit ratio 1:10). The financial cost of the programme at public-health system level was € 50 000 (specialist visit, colonoscopy plus removal of adenoma). The benefit was calculated to be € 700 000 by avoided hospital stay and surgery (cost-benefit ratio 1:14). In the future our workplace based programme will be offered routinely.

References

(1) ECHO: Workplace based faecal occult blood screening. Occup Environ Med 2004; 61,413

(2) Webendörfer S, Messerer P, Eberle F et al. Darmkrebs-Vorsorge im Betrieb. Dtsch Med Wochenschr 2004; 129: 239-243

Dear Editor

Atkinson et al,[1] reported “particularly among those monitored for plutonium exposure there was a significant excess mortality from cancer of the pleura”.

However, they also note the lack of a trend for radiation dose. The authors’ suggest that these cancers are mostly mesothelioma and that asbestos is the likely causative agent. There is no mention of other agents that can cause mesothelioma; although they elude to other causes (“…are strongly related to exposure to asbestos.”). I would like to point out that others [2-4] reported ionizing radiation as a possible aetiological agent for mesothelioma. This appears to include a case4 involving short- term ionizing radiation exposure. In addition, mesothelioma appears to be caused by a number of other agents (e.g. sugar cane, viruses)[5,6] besides asbestos and radiation. It has been suggested that non-asbestos causes of mesothelioma may be as high as 87%,[7] although a lower percent has been reported (around 13%).[8] Readers need to be aware that there appears to be many agents, including spontaneous events5, which may be responsible for cases of pleural cancer (mesothelioma).

References

1. Atkinson WD., Law DV., Bromley KJ., Inskip HM. Mortality of employees of the United Kingdom atomic energy authority, 1946-87. Occup Environ Med. 2004; 61:577-85.

2. Lerman Y, Learman Y, Schachter P, Herceg B, Lieberman Y, Yellin A. Radiation associated malignant pleural mesothelioma. Thorax. 1991;46:463- 4.

3. Hoffman J, Mintzer D, Warhol MJ. Malignant mesothelioma following radiation therapy. Am J Med. 1994;94:379-92.

4. Mizuki M, Yukishige K, Abe Y, Tsuda T. A case of malignant pleural mesothelioma following exposure to atomic radiation in Nagasaki. Respirology. 1997;2:201-5.

5. Hubbard R. The aethiology of mesothelioma: are risk factors other than asbestos exposure important? Thorax 1997;52:406-7.

6. Lange JH. Other non asbestos causes of mesothelioma besides the SV40 virus. (eletter) Thorax. 2004; http://thorax.bmjjournals.com/cgi/eletters/57/4/353#161

7. Peterson JT, Greenberg SD, Buffler PA. (1984) Non-asbestos-related malignant mesothelioma: a review. Cancer 54:951-60.

8. Yates DH, Corrin B, Stidolph PN, Browne K. Malignant mesothelioma in south east England: clincopathological experience of 272 cases. Thorax 1997:52:507-12.

Dear Editor

Gimeno, Amick, Benavides and Benach [1] raise a number of issues with a paper recently published in Occupational and Environmental Medicine.[2] It is important that researchers cross-examine others’ findings and conclusions, as well as explain and defend their own findings and conclusions, so that debate can proceed that is both informed and useful for policy and practice.

In the original paper, I present findings that suggest the perceived risk from occupational stress varied across countries in the EU. I interpreted the findings as suggesting an element of social construction is present in such perceived risk, and that this element of social construction could have implications for policy, in respect of risk communication, for example.

There are two important things to note about these conclusions.

First, I analysed perceived risk from occupational stress, and not objective risk. These are recognised as two separate entities.[3] Whilst they are arguably intertwined closely in occupational stress and emotional health,[4] these data do not speak to this issue, and I drew no conclusions concerning objective risk. However, perceived risk is an important issue that can have practical implications, as noted.[2]

Second, it is uncontroversial in many areas concerned with risks to health (e.g. nuclear power, food) that risk is partially socially constructed, at this social construction has important practical implications.[5] There is no reason I know of why there should be controversy concerning the practical implications of a socially constructed element to risk from occupational stress.

Gimeno et al. raise four concerns.

1. The first issue is related to sample selection. The data were drawn from the Third European Survey on Working Conditions (ESWC), and then a more homogenous sample selected of people working in the same country as their nationality. Albeit imperfect (as noted by Gimeno et al), this procedure excludes workers who are more likely to have recent extensive experience of different working cultures. As noted in the paper, then, ‘variation within individuals due to multiple influences of work cultures was minimized’. Note I use the term minimized, rather than excluded. Notwithstanding, this procedure provides a more accurate means of assessing socio-cultural influences on perceived risk of occupational stress than was possible just by comparing responses across country of data collection or by comparing people of different nationalities.

Gimeno et al. explain that there is an influx of foreign workers into the EU, and that these workers may be exposed to more hazardous working conditions. Gimeno et al. make the argument that ‘removing workers who may be experiencing the greatest stress and hazardous working conditions from the sample may represent a severe selection bias’. I would agree with Gimeno et al.had the purpose of the paper been to determine objective risk in all areas of the labour market in the countries surveyed. Further, I agree that such workers are an important section of EU labour markets deserving of research in their own right with a view to informed intervention to enhance their working conditions – and such research should include assessment of perceived and objective risk in due course.

However, the purpose of the paper was to determine whether there is a socially constructed element in the perceptions of stress that can be attributed to socio-cultural variables at the national level. Including such workers may well have skewed the data by introducing a level of bias related to the nationality of immigrant workers in a country.

Gimeno note ambiguity with the statement "individuals who were working in a different country as their nationality". As well as re- reading the paper, I have conducted an electronic search of the paper, and cannot find this quote. Therefore I am unsure of the context of the quote, and so cannot be sure of the source of the perceived ambiguity. However, Gimeno et al. do raise issues not covered in the ESWC data concerning assimilation of social constructs and life-course data, all of which are relevant to propagation of cultural values at an individual level [6] and possibly also risk perception. However, by including only those people who list their nationality as being the same as the country they work in, it is a reasonable assumption that they will be familiar with the dominant cultural values of that country (even if they do not subscribe to those values themselves). Other data would be desirable of course, but unfortunately, they are not available.

2. The second concern raised by Gimeno et al concerns the use index of perceived risk of occupational stress. They raise an issue concerned with principal components analysis (PCA) conducted on the whole sample, rather than the sub-set used to compare the EU countries. It seems that the implication of this argument is that a different cluster of symptoms would be uncovered by PCA conducted on the sub-sample. I re-analysed the data, using only those people that worked in the same country as their nationality. PCA indicated the same pattern of relationships between perceived risk of symptoms.

What does this analysis mean though? It seems that a cluster of symptoms – which may be labelled stress – are commonly perceived as co- occurring. This might be because when such symptoms occur, they commonly occur together. This could reflect a physiological process, or heightened cognitive processing of physical sensations during emotional episodes.[7] However, as other analyses in [2] show, the extent to which the risk of experiencing these symptoms is attributed to work has a socially constructed component.

Gimeno et al. do raise the point that important differences might exist between individual health-related outcomes, and that these health- related outcomes might vary between factors such as type of employment, gender etc. First, in [2], I did control for industry, demographic factors, job dissatisfaction and perceived working conditions. In this way, factors that might represent cross-national variations in working practices (such as working hours) and individual level factors (such as job dissatisfaction) could not be said to account for the pattern of findings. Second, the ESWC contains many individual level questions assessed by single item indicators. By looking at health outcomes assessed by single indicators, there is danger that any findings reflect the error of measurement embedded in single item indicators of indeterminate reliability - rather than the true variable of interest. This threat is magnified in analyses involving large samples, where even small differences due to error can be labelled statistically reliable. By producing a scale – with an acceptable reliability coefficient (a=0.73), this possibility is lessened.[2]

Gimeno et al. also bring attention to the nature of the questions in the ESWC that I used to examine cross-national differences. It is important to note that the question I used asked participants to attribute various symptoms to work, not whether those symptoms were currently being experienced. Therefore, the question reflects a perception of the impact of work on symptoms – and not symptoms themselves or any underlying pathology. Therefore, any conclusions drawn from the data cannot reflect anything other than factors influencing the perceived influence of work on various symptoms.

3. The third concern raised by Gimeno et al regards the empirical status of my conclusion that workers in lower ranked countries might be less likely to attribute minor or non-specific psychosomatic symptoms to work when consulting with health practitioners. Whilst Gimeno et al are aware of no data that support such a conclusion, this conclusion – however conditional the language within which it is phrased - cannot be dismissed without further work. There is evidence that indicates emotional displays and discussion of life stress during consultation might cause misdiagnosis.[8] This potential for misdiagnosis arguably warrants further investigation.

4. The fourth concern raised by Gimeno et al. concerns the discussion section, especially in relation to conclusions with respect to the UK. I conclude that the media and socio-cultural factors – specifically cultural attitudes – might influence perceptions of risk from occupational stress. There is an extensive literature relating to these issues in relation to other risks – and some of the more prominent examples were referenced in [2]. There is also discussion elsewhere of socio-cultural factors and the media in influencing perceptions of risk from occupational stress [9] and in politicising stress as a social issue that subsequently influences reporting of stress.[10]

Gimeno et al. suggest that classifying countries according to common characteristics could provide an a priori basis for explaining the pattern of findings. The cultural approach to risk perception [11] provides one such approach. In this framework, countries with an individualist orientation (Ireland and Great Britain in this sample) would be expected to be ranked lower than other countries. This was indeed the case in [2]. However, countries with a more egalitarian orientation, such as the Nordic countries and Germanic countries, would be predicted to be ranked near the top, and countries with more hierarchical work cultures – such as France – would be expected to be ranked lower than the Nordic and Germanic countries. The results clearly do not bear such predictions out (see 12 for a cultural typology of European countries).

Therefore, the ranking of countries may reflect more complex processes than simple categorisation of countries on cultural or other factors. This conclusion is supported by some of the literature cited in [2] that has been used to discuss the British case [9,13-15]. In this literature, a number of suggestions have been made, in which, factors such as the media, socio-cultural factors and cognitive processes in the perception of risk have been advocated as explanations or partial explanations for perceived risk from occupational stress. I do not know the extent to which the scientific and policy literature in other countries covers such issues, but the fact there is open debate in the scientific community concerning such issues in Britain makes Britain a useful focus for analysis. Moreover, the British case with respect to monitoring stress and intervention is now more interesting, given the introduction of Stress Management Standards by the UK Health and Safety Executive. In due course, the British case will provide a useful focus for analysis of how advisory rather than coercive processes influence reporting and perception of occupational stress. It was for these reasons that the discussion section had some focus on the British case.

So rather than further cross-national comparisons on perceptions of stress – now we know they exist but not why - researchers might find it useful to examine individual countries on a case-by-case basis, so as to build rich pictures of the factors that influence perceived risk from stress in any one societal context and explain in more detail the pattern of findings in [2]. Once such exploratory work has been completed, research can move to hypothesis testing.

Finally, Gimeno et al. note that different rankings are apparent if different dependent variables are used. This should not be surprising – I can think of no reason why sickness absence has to necessarily mirror findings with attributions of stress-related symptoms to work – although there might be several reasons why they could be loosely coupled. Stress is not the only reason for absence from work.

Whether the ranking in [2] is more or less accurate and the reasons for the rankings, only further research can tell. However, the socially constructed elements of stress have real policy implications. They are worthy of further debate and research. To ignore them or deny them ultimately will be to the detriment of policy, intervention and occupational health.

References

1. Gimeno, D, Amick III BC, Benavides FG, Benach J. Bias and caution. Occup Envirn Med On-line 2004, http://oem.bmjjournals.com/cgi/eletters/61/5/467

2. Daniels, K. Perceived risk from occupational stress: a survey of 15 European countries. Occup Environ Med, 2004; 61: 467-70.

3. Royal Society. Risk: Analysis, Perception and Management. London: Royal Society, 1992.

4. Daniels K, Harris C, Briner R. Understanding the Risks of Stress: A Cognitive Approach. Sudbury: HSE Books, 2002.

5. Kasperson RE, Kasperson JX, Renn O. The social amplification of risk: progress in developing an integrative framework. In S Krimsky, D Golding (eds) Social theories of risk. London: Praeger, 1992.

6. Berry JW. Immigration, acculturation, and adaptation. Applied Psychology: An International Review, 1997; 46: 5-34.

7. Kirmayer LJ, Robbins JM, Paris J. Somatoform disorders: personality and the social matrix of somatic distress. Journal of Abnormal Psychology, 1994; 103: 125-136.

8. Ellington L, Wiebe D. Neuroticism, symptom presentation, and medical decision making. Health Psychology, 1999; 18: 634-643.

9. Daniels, K. Why aren’t managers concerned about occupational stress? Work & Stress, 1996; 10: 352-366.

10. Barley SR, Knight DB. Toward a cultural theory of stress complaints. In B.M.Staw & L.L. Cummings (Eds.), Research in organizational behavior, 1992; 14: 1-48.

11. Thompson M, Ellis R, Wildavsky A. Cultural Theory. Boulder: Westview, 1990.

12. Ronen S, Shenkar, D. Clustering countries on attitudinal dimensions: a review and synthesis. Academy of Management Review, 1985; 10: 435-454.

13. Wesseley S, Hotopf M. Are some public health issues better neglected? Lancet 2001; 357: 976-7.

14. Newton T. ‘Managing stress’ emotion and power at work. London: Sage, 1995.

15. Rick J, Hillage J, Honey S, Perryman S. Stress: big issue, but what are the problems? Brighton: The Institute for Employment Studies, 1997.

16. Gimeno D, Benavides FG, Benach J, Amick III BC. Distribution of sickness absence in the European Union Countries. Occup Environ Med (in press).