The incidence of occupational skin disease as reported to The Health and Occupation Reporting (THOR) network between 2002 and 2005

BACKGROUND

Estimated incidence rates for occupational skin disease in the U.K. are provided by voluntary surveillance schemes involving dermatologists and occupational physicians. These rates allow monitoring of occupational dermatoses, and intervention planning aimed at reducing workplace risks.

OBJECTIVES

To summarize occupational skin disease reported to The Health and Occupation Reporting (THOR) network (2002-2005), and to provide baseline information for comparison with future studies of occupational skin disease in the U.K. and beyond.

METHODS

Incidence rates for occupational dermatoses were calculated using THOR data as numerators, and Labour Force Survey data or information from the most recent U.K. survey on provision of occupational physician services as denominators.

RESULTS

In the U.K. (2002-2005) the average annual incidence rate of work-related skin disease reported to THOR by dermatologists was 91.3 [95% confidence interval (CI) 81.8-101.1] per million, and by occupational physicians was 316.6 (95% CI 251.8-381.3) per million. Most reports were of contact dermatitis: dermatologists 68.0 (95% CI 59.8-76.2) per million, occupational physicians 259.7 (95% CI 200.8-318.6) per million.

CONCLUSIONS

Information produced by THOR is an important source for calculating incidence rates of occupational skin disease. A range of reporting groups should also be used when building an overall picture of occupational skin disease incidence in the U.K.

Occupational dermatitis related to chromium and cobalt: experience of dermatologists (EPIDERM) and occupational physicians (OPRA) in the U.K. over an 11-year period (1993-2004)

BACKGROUND

Chromium and cobalt (and their compounds) are well recognized as being important causes of occupational contact dermatitis (OCD), particularly of the hands, although their exact contribution to occupational hand dermatitis varies between different studies. In some European studies, cases of chromium-related dermatitis have decreased following the addition of ferrous sulphate to cement to reduce the amount of available chromium.

OBJECTIVES

To examine, using data from the U.K. occupational skin surveillance schemes, the proportionate reported incidence and changing trends in OCD considered to be related to chromium and cobalt for the 11-year period from February 1993 to December 2004.

METHODS

Surveillance data collected by the two British occupational health surveillance schemes, EPIDERM and OPRA, from February 1993 to December 2004 were studied. These are occupational health surveillance schemes in the U.K. to which physicians voluntarily and anonymously report new cases of skin disease suspected to be work related.

RESULTS

Over the 11-year period, dermatologists reported 22 184 cases of OCD, comprising 77% of all types of occupational skin diseases that were disclosed. Chromium was recorded as being thought to play a role in 1226 (6%) of these, with cobalt identified as being likely to be implicated in 823 (4%). The numbers fluctuated on a year-on-year basis but there were no overall trends during the period of study. The male/female ratio was 5 : 1 for chromium and 1 : 1 for cobalt. Overall, the male/female ratio for OCD was 1.4 : 1. The rates of dermatitis believed to be related to both metals generally increased with age. In women, the highest rate for chromium was seen in the > 60 years age group, whereas conversely, for cobalt the rate decreased with age. For chromium-related OCD the most common occupations were builders and building contractors, bricklayers, construction workers and plasterers. For cobalt-related OCD, the commonest occupations were hairdressers/barbers, builders/building contractors, retail cash/checkout operators, machine operatives and domestic cleaners. Occupational physicians reported 15 016 cases of OCD (82% of all occupational skin diseases reported by them) for the period May 1994-December 2004. Of these, only 38 cases were thought to be related to chromium and 30 to cobalt (25 of the latter were processing labourers).

CONCLUSIONS

In this series, chromium was reported by dermatologists as potentially being involved in 6% of all cases of OCD in the U.K., and cobalt in 4%. Our data support the view that chromium-related dermatitis has an onset in later working life and often affects those in the building trades, whereas cobalt-related dermatitis seems to have an earlier onset and may affect a wide range of employments.

Specialist competencies in occupational medicine: appraisal of the peer-reviewed literature

BACKGROUND

A re-assessment of competencies and therefore learning outcomes for higher specialist training in occupational medicine (OM) is being undertaken. Although peer-reviewed literature on the subject exists, it is limited and needs appraisal.

AIMS

To search, and critically appraise the peer-reviewed literature on specialist competencies in OM.

METHODS

Systematic search of a range of databases of peer-reviewed literature, followed by criterion based appraisal and categorization of the findings.

RESULTS

Two hundred and thirty five papers were found of which only 20 were left after application of the grading and exclusion criteria. These addressed competencies from four perspectives: peer consensus, client, educational and legal.

CONCLUSIONS

Limited evidence can be obtained from the peer-reviewed literature on specialist competencies in OM. However, it suggests the main paradigms for deriving these competencies as well as indicating gaps and the manner in which these might be filled.

Preference of distance learning methods among post-graduate occupational physicians and hygienists

BACKGROUND

The Centre for Occupational and Environmental Health at the University of Manchester has successfully run distance-learning courses for a number of decades. These are based on hundreds of pages of (paper-based) written text, specially commissioned, packaged and distributed in eight binders. Converting printed text to an online format has the potential to improve learning through the benefits of information and communication technology as well as to save printing and distribution costs.

AIM

To determine which distance learning method is preferred by postgraduate occupational health students: paper-based text, or online text with embedded interactive questions and separate practical exercises.

METHODS

From approximately 50 paper-based textual course sub-units, one was converted to an online format, incorporating a variety of interactive text and supplemental practical exercises. Occupational medicine and hygiene students were provided with both the paper-based and online versions and asked, via anonymous postal questionnaire, a series of questions, including their preference for future course sub-units.

RESULTS

Sixty-two replies were received from 91 registered students (68% response). Apart from one student who had never tried the internet, all others described themselves as 'frequent' or 'occasional' internet users, with 78% having access both at home and work. Opinion was overwhelmingly positive with regard to ease of navigation, quality of the interactive exercises and online photo quality. Students tended to prefer multiple-choice questions and photo exercises and disliked interactive functions asking for words to complete paragraphs. Regarding preference for future teaching sub-units, the majority of students answering this question (67%) expressed a desire for mostly paper-based text supplemented with interactive online exercises.

CONCLUSION

Currently enrolled students prefer core teaching materials to remain in the printed medium, with the addition of online practical exercises to supplement learning.

The incidence of work-related illness in the UK health and social work sector: The Health and Occupation Reporting network 2002–2003

BACKGROUND

In the United Kingdom, The Health and Occupation Reporting network (THOR) collects incidence data on work-related illness. THOR data show that the health and social work sector generates a high proportion of case reports. This study analyses the most recent data for the health and social work sector, from 2002 to 2003.

METHODS

Cases returned to the Occupational Physicians Reporting Activity (OPRA) scheme and three other specialist schemes (Surveillance of Occupational Stress and Mental Illness, Musculoskeletal Occupational Surveillance Scheme and occupational skin surveillance) were analysed. Estimates of incidence rates for stress-related illness, musculoskeletal disorders and skin disease were calculated using two denominators.

RESULTS

In this period, 23% (11,016/47,437) of all estimated cases in THOR were in health and social work sector employees. In OPRA, in the health and social work sector, annual average incidence rates per 100,000 calculated using Labour Force Survey (LFS) data as the denominator were 51.2 for mental illness, 35.9 for musculoskeletal disorders and 10.4 for skin disease; using McDonald's data as the denominator the corresponding rates were 119.5, 83.7 and 24.3. In the specialist THOR schemes, annual average incidence rates per 100,000 using LFS data as the denominator were 18.4 (mental illness), 6.1 (musculoskeletal disorders) and 15.3 (skin disease).

CONCLUSIONS

Our results highlight the importance of collecting information on incident cases and denominators, to allow calculation of occupational disease rates. The higher incidence of mental illness (compared with musculoskeletal and skin disorders) in this employment sector merits further investigation.

Physicians' beliefs in the assessment of work attribution when reporting musculoskeletal disorders

BACKGROUND

There is considerable uncertainty about work-relatedness and musculoskeletal disorders in general, and it is also not clear how physicians decide whether work has caused a disorder in an individual patient.

AIMS

To investigate physicians' beliefs about assessment of occupational attribution for work-related musculoskeletal disorders.

METHODS

A questionnaire survey was sent to 526 occupational physicians and 248 rheumatologists on: characteristics of cases seen, assessment of work attribution, definition of work-relatedness and threshold for case reporting. Continuous variables were analysed by mean, standard deviation, an independent two-sample t-test and the Mann-Whitney test. Mean and median values were calculated and Spearman's rank test was applied to ranked data.

RESULTS

Questionnaires were completed by 68% occupational physicians and 64% rheumatologists. Both groups of physicians believed that 'history of onset in relation to workplace changes' and 'symptoms consistent with work exposure' were the most important factors suggesting work attribution. They considered that the most important objective of a reporting scheme was detection of trends in disease incidence and that the most suitable criteria for defining work-relatedness was the probability that exposure at work 'more likely than not' caused the condition (mean 0.73; SD=0.17), in a perceived likelihood scale (0-1).

CONCLUSION

There was a strong agreement between occupational physicians and rheumatologists on questions about work-relatedness and musculoskeletal disorders. The level of probability for concluding work-relatedness has been quantified.

A study of work-related musculoskeletal case reports to The Health and Occupation Reporting network (THOR) from 2002 to 2003

BACKGROUND

Occupational musculoskeletal disorders are frequently seen by occupational physicians and rheumatologists, and there are well-established UK-based schemes set-up for reporting these conditions. An apparent fall in case reporting for work-related musculoskeletal disorders in Great Britain to The Health and Occupation Reporting network (THOR) was observed from 2002 to 2003.

AIMS

To investigate changes in case reporting for musculoskeletal disorders sent by occupational physicians to Occupational Physicians Reporting Activity (OPRA) and by rheumatologists to Musculoskeletal Occupational Surveillance Scheme (MOSS) between 2002 and 2003.

METHODS

Musculoskeletal cases returned by more than 800 physicians from Great Britain reporting to OPRA and MOSS in 2002-2003 were analysed. Changes in reporting are described at individual physician and group levels in: numbers of participants, levels of response, and numbers of case reports by disease category and major occupational and industrial groups.

RESULTS

In 2002-2003, musculoskeletal disease was the most frequently reported major disease category in OPRA. Between 2002 and 2003, the proportion of musculoskeletal case reporting fell by 37% in OPRA, and 7% in MOSS. This fall was seen in many disease categories, across a wide range of occupations and industries. In OPRA, the greatest fall in reporting (74%) was for the category Raynaud's/Hand-Arm Vibration Syndrome/Vibration White Finger.

CONCLUSIONS

The fall in occupational musculoskeletal case reporting between 2002 and 2003 cannot be explained by internal factors within the reporting system. This observation highlights the need for systematic investigation of trends in case reporting for work-related ill-health.

Work-related infectious disease reported to the Occupational Disease Intelligence Network and The Health and Occupation Reporting network in the UK (2000–2003)

BACKGROUND

Infectious diseases remain an important cause of self-reported work-related illness, with socio-economic consequences, including sickness absence. Reporting of infectious disease by occupational and specialist physicians is an important tool in the investigation of occupationally related infections and is relevant in their management.

AIMS

To examine the reporting of cases of infectious disease by occupational and specialist physicians to schemes collecting data on occupational ill-health.

METHODS

Cases of infectious disease reported by occupational and specialist physicians to the UK based schemes, Occupational Disease Intelligence Network (ODIN) and The Health and Occupation Reporting network (THOR), from 2000 to 2003 were analysed by reporting patterns, diagnosis, single case or outbreak reporting and industry.

RESULTS

The total number of estimated cases of infectious disease reported to ODIN and THOR from 2000 to 2003 was 5606; 74.9% cases were diarrhoeal disease, and 11.1% scabies. The majority (81.4%) of cases were reported in SIDAW, where the participation rate for reporters was 55%. Reporting rates were much higher in OPRA, SWORD and EPIDERM (ranging from 86 to 96%). The most frequently reported industrial sectors were social care (39.5%) and health (29.4%); while the manufacture of chemical products contributed 4.3% overall, but 33.8% to estimated cases in OPRA.

CONCLUSIONS

Despite limitations related to under reporting, the occupational and specialist physician schemes in ODIN and THOR provide data that may be used to look at patterns of case reporting for occupational ill-health, including infectious disease. The reporting schemes also provide an important means of alerting peers about potential novel causes, precipitating factors, or industrial sectors associated with occupational disease.

Relationship between chemical structure and the occupational asthma hazard of low molecular weight organic compounds

AIMS

To investigate quantitatively, relationships between chemical structure and reported occupational asthma hazard for low molecular weight (LMW) organic compounds; to develop and validate a model linking asthma hazard with chemical substructure; and to generate mechanistic hypotheses that might explain the relationships.

METHODS

A learning dataset used 78 LMW chemical asthmagens reported in the literature before 1995, and 301 control compounds with recognised occupational exposures and hazards other than respiratory sensitisation. The chemical structures of the asthmagens and control compounds were characterised by the presence of chemical substructure fragments. Odds ratios were calculated for these fragments to determine which were associated with a likelihood of being reported as an occupational asthmagen. Logistic regression modelling was used to identify the independent contribution of these substructures. A post-1995 set of 21 asthmagens and 77 controls were selected to externally validate the model.

RESULTS

Nitrogen or oxygen containing functional groups such as isocyanate, amine, acid anhydride, and carbonyl were associated with an occupational asthma hazard, particularly when the functional group was present twice or more in the same molecule. A logistic regression model using only statistically significant independent variables for occupational asthma hazard correctly assigned 90% of the model development set. The external validation showed a sensitivity of 86% and specificity of 99%.

CONCLUSIONS

Although a wide variety of chemical structures are associated with occupational asthma, bifunctional reactivity is strongly associated with occupational asthma hazard across a range of chemical substructures. This suggests that chemical cross-linking is an important molecular mechanism leading to the development of occupational asthma. The logistic regression model is freely available on the internet and may offer a useful but inexpensive adjunct to the prediction of occupational asthma hazard.

[Assessment of appropriateness and verification of interventions in the professional practice of the occupational physician]

Evaluation of Occupational Health Practice is both an intriguing research field and an essential tool to assure the quality of intervention. The objectives of this paper are: (i) to define the principles of evaluation and the role of quality assurance of intervention, (ii) to define the principles of audit of professional practice, (iii) to outline the role of research in evaluating and improving intervention and other practice.

Particulate air pollution and the blood

BACKGROUND

Particulate air pollution has been associated with excess deaths from, and increases in hospital admissions for, cardiovascular disease among older people. A study was undertaken to determine whether this may be a consequence of alterations in the blood, secondary to pulmonary inflammation caused by the action of fine particles on alveolar cells, by repeatedly measuring haematological factors in older people and relating them to measurements of exposure to airborne particles.

METHODS

One hundred and twelve individuals aged 60+ years in two UK cities provided repeated blood samples over 18 months, 108 providing the maximum of 12 samples. Estimates of individual exposure to particles of less than 10 microm diameter (PM(10)), derived from a mathematical model based on activity diaries and comparative measurements of PM(10) at multiple sites and during a variety of activities, were made for each three day period prior to blood sampling. The relationships between blood values and estimates of both personal exposure and city centre measurements of PM(10) were investigated by analysis of covariance, adjusting for city, season, temperature, and repeated individual measurements.

RESULTS

Estimated personal exposure to PM(10) over the previous three days showed negative correlations with haemoglobin concentration, packed cell volume (PCV), and red blood cell count (p<0.001), and with platelets and factor VII levels (p<0.05). The changes in red cell indices persisted after adjustment for plasma albumin in a sample of 60 of the subjects. City centre PM(10) measurements over three days also showed negative correlations with haemoglobin and red cell count (p<0.001) and with PCV and fibrinogen (p<0.05), the relationship with haemoglobin persisting after adjustment for albumin. C reactive protein levels showed a positive association with city centre measurements of PM(10) (p<0.01). Based on a linear relationship, the estimated change in haemoglobin associated with an alteration in particle concentration of 100 microg/m(3) is estimated to have been 0.44 g/dl (95% CI 0.62 to 0.26) for personal PM(10) and 0.73 g/dl (95% CI 1.11 to 0.36) for city centre PM(10) measurements.

CONCLUSIONS

This investigation is the first to estimate personal exposures to PM(10) and to demonstrate associations between haematological indices and air pollution. The changes in haemoglobin adjusted for albumin suggest that inhalation of some component of PM(10) may cause sequestration of red cells in the circulation. We propose that an action of such particles either on lung endothelial cells or on erythrocytes themselves may be responsible for changing red cell adhesiveness. Peripheral sequestration of red cells offers an explanation for the observed cardiovascular effects of particulate air pollution.