Health and Safety
Executive / Commission
Statistics
Data from four sources have been examined to assess whether there are differences in the occurrence of work-related illness between younger and older workers (or ex workers). The sources used were the Self-reported Work-related Illness surveys of 1995 (SWI95) and 1998/99 (SWI98/99); surveillance reports for the three years 1998-2000 from the Occupational Disease Intelligence Network (ODIN); and the Self-reported Work-related Conditions Survey of 1995 (SWC). In this analysis 'younger' means age 16-44, and 'older' age 45-64 (for the SWI data: 45-59 for women).
The conclusions of this analysis are as follows:
There is most evidence of a statistically significant increase when considering the SWI95 data; all but one of the main complaints shows a significant increase in ill health with age. There is similar evidence of a statistically significant increase when considering values in SWI98/99. The ODIN information also suggests an increase in the rate of ill health (as indicated by the ratio of rates between older and younger workers). Contrary to SWI95 and SWI98/99, there are few occurrences of statistically significant differences by age in the SWC information.
Details of each data source are included towards the end of this document in 'Information on data sources'
Taking into account the figures in all four tables, there is evidence that the rate of stress, depression and anxiety in the older age group is higher than in the younger group.
It is evident from Table 1 (SWI95), that the prevalence rate in the older age group is greater than the rate in the younger group for males, females and all persons; these are all statistically significant increases. Values in Table 2 (SWI98/99) show differences in the same direction. For females and all persons, there are increases that are statistically significant; for males, the difference is not statistically significant. In Table 3 (ODIN), the incidence data portray a similar situation, although it is not possible to determine whether these differences are statistically significant (-see 'Information on data sources' below.) In contrast, working conditions associated with stress, depression or anxiety in Table 4 (SWC) (the first four descriptions in the table) generally show no discernable differences between old and young workers for any of the working conditions; the exception being that there is a significant decrease between females in the younger and older groups for the working condition 'Getting insufficient help and support from people in charge when needed'.
Overall, there is evidence of an increase in musculoskeletal disorders in the older working age group compared to the younger. Table 1 (SWI95) shows not only statistically significant increases in prevalence rates for all musculoskeletal disorders, but also for each of the three sites affected, for males, females and all persons. Likewise, it can be seen in Table 2 (SWI98/99) that there is a significant increase for males, females and all persons. It is evident in Table 3 (ODIN) that although there is generally an increase in the incidence rate when comparing older workers to younger workers, these increases are more modest than those in Table 1, Table 2. In Table 4 (SWC), the working conditions relating to musculoskeletal disorders are the final five in the list. Most of the differences between younger and older workers are not significant, although there is a significant increase for males and all persons for 'Twisting or stooping when lifting or moving heavy loads'. Conversely, there are significant decreases in the rate of older workers compared to younger workers for males and all persons in 'Using appreciable force' and 'Lifting or moving heavy loads'.
There is some evidence of an increase in lower respiratory illness rates between the two age groups. Data in Table 1 (SWI95) exhibit significant increases in prevalence rates between older workers and younger workers in all categories for this complaint. Nevertheless, some of the rates for males and females are based on less than 30 sample cases. For the incidence data in Table 3 (ODIN), there is an increase in the asthma rate of approximately 1.5 for males, females and all persons. In Table 4 (SWC), the working condition most closely associated with lower respiratory disease is 'workers ever exposed to breathing fumes, dusts and other harmful substances in their job'. It can be seen here that there are no discernable changes in the rates between younger and older workers.
There is very little evidence to suggest a change in rates of skin disease. There are no statistically significant differences between the rates for any of the data sources, although there is generally a reduction in the rate of older female workers compared with younger female workers in Table 1 (SWI95) and Table 3 (ODIN). All values for skin disease in Table 1 (SWI95) are based on less than 30 sample cases.
It can be seen from Table 1 (SWI95) that there is a significant increase for both the male rate and all persons rate from younger to older workers; however, many of the values in the table are based on less than 30 sample cases. Table 4 (SWC) does not show any significant differences.
Voluntary surveillance schemes for the reporting of occupational disorders are coordinated by the University of Manchester with HSE funding, and provide information on the incidence of work related ill health. They include schemes known as SWORD1 (Surveillance of Work-related and Occupational Respiratory Disease), EPIDERM2 (Occupational Skin Surveillance Scheme Reported by Dermatologists), MOSS (Musculoskeletal Occupational Surveillance Scheme), and SOSMI (Surveillance of Occupational Stress and Mental Illness)3, and others, and are all incorporated under the umbrella scheme known as ODIN (Occupational Disease Intelligence Network). These schemes count new cases that are caused by work in the opinion of the specialist doctor who sees them. Statistics presented here are for occupational respiratory, skin, musculoskeletal disorders and psychological disorders (including stress). It should be noted that not all cases of occupational disease are seen by participating specialists. In MOSS and SOSMI, unlike the other specialist schemes, the physicians are advised to report cases either caused or made worse by work. In all schemes, a very high proportion of physicians in the relevant specialities participate systematically and voluntarily.
In most of these schemes, there is a sampling process whereby most participating doctors are asked to send in reports for one month in each year, and the numbers of cases that they report are multiplied by 12 in arriving at the estimated annual totals. All the figures presented here are rates derived from the estimated annual totals rather than rates bases on actual numbers of reported cases. Therefore, it should be remembered that many of the estimated numbers shown are based on smaller (often considerably smaller) numbers of actual reported cases. The incidence rates for ODIN cases, per 100 000 workers in each occupation or industry, are calculated using denominators from the Labour Force Survey (LFS). As an alternative to confidence intervals, ratios of incidence rates between old and young workers are included; however, these ratios are for indicative purposes only, as no statistical conclusions can be inferred. It should be noted that information collected by the OPRA scheme has not been included in this analysis due to the fact that the age distribution of cases presented to Occupational Physicians will be biased.
Results from a survey of self-reported work-related illness in 1998/99 (commissioned by the European Union Statistical Office (EUROSTAT)) have recently been published on the HSE website4. This is the third survey of self-reported work-related illness undertaken in conjunction with the Labour Force Survey (LFS) to gain a view of work-related illness based on individuals' perceptions. The Health and Safety Executive (HSE) commissioned the second survey in 1995, which is known as SWI955 (surveys of Self-reported Work-related Illness).
These two surveys provide an indication of the overall prevalence of work-related illness and its distribution by major disease groups and a range of demographic and employment-related variables. Responses obviously depend on lay people's perceptions of medical matters, but such perceptions are of interest and importance in their own right. However, they cannot be taken directly as an indicator of the 'true' extent of work-related illness as people's beliefs may be mistaken: they may ascribe the cause of illness to their work when there is no such link; and they fail to recognise a link with working conditions when there is one.
All estimates derived from these surveys are subject to a margin of error. The main factor which determines the width of the margin is the number of sample cases an estimate is based on. In the published report for each survey4,5, the sampling errors have been expressed as 95% confidence intervals. Each of these represents a range of values that has a 95% chance of containing the true value. However, confidence intervals have been quoted whenever there are less than 30 sample cases.
The differences in the design, coverage and level of information collected means that only broad comparisons can be made between the results of each survey, and even these need to be treated with caution. More details about the differences and how comparable estimates were derived can be found in the SWI98/99 published report4.
The Omnibus survey, otherwise known as SWC6 (Self-reported working conditions in 1995) was designed to help identify features of the job which may be associated with a work-related illness a control population. Respondents were asked the same questions on working conditions that appeared in the follow-up questions for sufferers of work-related illness. In addition, to aid interpretation of the main survey the same questions on chest problems, smoking and general health were asked so that background levels of certain health problems could be determined. The control population questions were included in two monthly cycles of the Office for National Statistics (ONS) Omnibus survey (in August and October 1995).
1 Meredith SK, Taylor VM, McDonald J 'Occupational respiratory disease in the United Kingdom 1989: A report to the British Thoracic Society and the Society of Occupational Medicine by the SWORD project group' British Journal of Industrial Medicine 1991 48 292-298.
2 Cherry N, Meyer J, Adisesh A et al. 'Surveillance of occupational skin disease: EPIDERM and OPRA' British Journal of Dermatology 2000 142 1-8.
3 Cherry N 'Recent advances: occupational disease' British Medical Journal 1999 318 1397-1399.
4 Jones J R, Huxtable C S and Hodgson J T 'Self-reported work-related illness in 1998/99: Results from a EUROSTAT ill health module in the 1999 Labour Force Survey summer quarter', 2001. Published on the Internet at www.hse.gov.uk/hthdir/noframes/euro9899.htm.
5 Jones J R, Hodgson J T and Clegg T A 'Self-reported work-related illness in 1995' HSE Books 1998 ISBN 0 7176 1509 X. . Published on the Internet at http://www.hse.gov.uk/statistics/2002/swi95.pdf.
6. Jones JR, Hodgson JT, Osman J. Self-reported Working Conditions in 1995: Results from a household survey, HSE Books 1997 ISBN 0 7176 1449 2. Published on the Internet at http://www.hse.gov.uk/statistics/2002/swc95.pdf