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Biomedical subjects

D Coggon

Publications and source records attributed to D Coggon.

At least 19 recordsLinked to original sources

Questionnaire based exposure assessment methods.

In environmental epidemiological studies, questionnaires may be the method of choice for assessing exposure because no other source of information is available, or because they provide the most efficient study design, allowing a larger study size and greater statistical power than would be possible with other more accurate measurement techniques. Problems may arise from a lack of content validity (the questionnaire does not cover all sources of exposure to the hazard of interest) or criterion validity (e.g., through inaccurate recall or misunderstanding of questions). Methods for validating questionnaires are described. The usefulness of validated 'standard' questionnaires is discussed, particularly in regard to comparison of exposure patterns in various populations studied separately. It is stressed that the validity of standard questionnaires should not be automatically assumed when they are applied to populations other than those in which they have been tested.

Environmental Exposure

Human papillomavirus DNA and TP53 mutations in lung cancers from butchers.

To investigate whether the high frequency of human papillomavirus infection in butchers may be linked to their higher than average incidence of lung cancer, we have examined lung cancers from 40 butchers and 26 controls for the presence of DNA from both HPV type 7, which is found almost uniquely in hand warts from butchers and fishermen, and for those HPV types associated with laryngeal and genital cancers. No HPV 7, and only a low frequency of HPV DNA was found, suggesting that HPV infection does not make an important contribution to the elevated levels of lung cancer in meat handlers. In addition, the frequency of p53 mutation was shown to be slightly lower than previously reported in lung cancers.

Adult

Management of sharps injuries and contamination incidents in health care workers: an audit in the Wessex and Oxford regions.

Fifteen NHS occupational health departments from the Wessex and Oxford regions took part in an audit of the management of sharps injuries and contamination incidents. Data were collected prospectively for a series of 1102 incidents notified over a nine-month period. The rates of notified incidents for each department ranged from 9 to 44 incidents per 1000 staff members per year. The proportion of injured employees who were naturally immune to hepatitis B or had completed a full course of vaccination against the infection ranged from 57 to 83%, with the main shortfall occurring in ancillary workers. Some departments rarely stored source serum, while others did so in the majority of cases. The proportion of cases where the injured person was known to have had hepatitis B antibody levels > 100 IU/l within the past 12 months, or underwent immediate antibody assessment or had an immediate vaccination against hepatitis B varied from 26 to 97%, with a median of 68%. On the basis of these findings, the audit group has set targets against which performance will be re-assessed in a follow-up exercise.

Accidents, Occupational

Osteoarthritis of the hip joint and acetabular dysplasia in women.

OBJECTIVE: To investigate the suggestion that osteoarthritis (OA) of the hip joint is often caused by subclinical acetabular dysplasia among elderly British women. METHODS: We examined 393 hip joints from the radiographs of a sample of women aged 60-75 years undergoing intravenous urography. Acetabular dysplasia was assessed using measurements of the centre-edge (CE) angle and acetabular depth (AD), which are both reduced in this condition. OA was assessed using an overall grade based on the Kellgren and Lawrence system and by measurement of minimum joint space (MJS). RESULTS: MJS was the more repeatable measure of OA, and showed a strong correlation with overall grade (Spearman rank correlation coefficient rs = -0.61, p < 0.01). MJS was significantly negatively correlated with CE angle (Pearson correlation coefficient r = -0.25, p < 0.001) and AD (r = -0.11, p < 0.05). Consistent with these findings, there was a weak but significant positive correlation between overall grade of OA and one of the two measures (CE angle) of acetabular dysplasia. CONCLUSIONS: These results do not support the hypothesis that mild degrees of acetabular dysplasia account for a substantial proportion of hip OA in elderly women. Changes in hip joint geometry as a result of OA may be responsible for the weak negative association observed.

Aged

Low back pain in Hong Kong: prevalence and characteristics compared with Britain.

STUDY OBJECTIVE: To compare the prevalence of low back pain and associated disability in Hong Kong with that in Britain, and to explore whether differences could be explained by certain known risk factors. DESIGN: A cross sectional survey with information collected at interview. Findings were compared with those from an earlier survey in Britain. SETTING: Two housing blocks in Hong Kong. SUBJECTS: Altogether 288 men and 364 women aged 18 years or older, who were resident in the two housing blocks and agreed to interview (response rate = 80%). MAIN RESULTS: Thirty nine per cent (95% confidence interval (CI) 34%, 44%) of interviewees reported having had low back pain at some time, and 21% (95% CI 18%, 25%) had had low back pain in the past 12 months. After standardisation for age and sex, all of the back symptoms examined were substantially less common in Hong Kong than in Britain. The one year period prevalence of low back pain was associated with occupational lifting (in both sexes) and with tall stature (in men only). Subjects tended to carry out less heavy lifting at work and to be shorter than participants in the earlier British study but these differences did not completely explain their lower prevalence of back pain. CONCLUSIONS: The findings indicate a lower prevalence of back symptoms in Hong Kong than Britain that is partly explained by differences in stature and occupational lifting. In addition, Hong Kong people may have a higher threshold for reporting symptoms, or they may differ in their exposure to other, unrecognised risk factors.

Adolescent

Mortality of butchers and cooks identified from the 1961 census of England and Wales.

OBJECTIVES: To explore a suspected hazard of lung cancer in butchers and cooks. METHODS: 4018 male butchers and 2062 male cooks were identified from the 1961 census of England and Wales. 4857 (79.9%) of these men were traced through the National Health Service Central Register, and 3518 deaths were recorded during follow up to the end of 1992. Mortality from lung cancer and other causes was compared with that of the general population by the person-years method. RESULTS: Mortality from all causes was significantly below that of the national population in both butchers (standardized mortality ratio (SMR) 0.94, 95% confidence interval (95% CI) 0.90-0.98) and cooks (SMR 0.89, 95% CI 0.84-0.95). When allowance was made for a latency of 20 years from entry to follow up, the deficit in butchers was reduced, but that in cooks persisted, and was largely explained by a shortfall of deaths from cancer and circulatory disease. Mortality from lung cancer was close to expectation in the butchers (SMR 1.01, 95% CI 0.90-1.13) and below expectation in the cooks (SMR 0.93, 95% CI 0.75-1.13). Cooks had increased mortality from cancers of the oral cavity (SMR 5.57) and pharynx (SMR 2.66). CONCLUSIONS: The findings provide no support for an occupational hazard of lung cancer in either butchers or cooks. The possibility of excess risk in sub-groups of these occupations cannot be discounted. The high rates of oral and pharyngeal cancer in cooks are probably a consequence of high alcohol consumption.

Cause of Death

Manual handling activities and risk of low back pain in nurses.

OBJECTIVE: To investigate the risk factors for low back pain in hospital nurses, with particular emphasis on the role of specific nursing activities. METHODS: A cross sectional survey of 2405 nurses employed by a group of teaching hospitals was carried out. Self administered questionnaires were used to collect information about occupational activities, non-occupational risk factors for back symptoms, and history of low back pain. RESULTS: The overall response rate was 69%. Among 1616 women, the lifetime prevalence of back pain was 60% and the one year period prevalence 45%. 10% had been absent from work because of back pain for a cumulative period exceeding four weeks. Rates in men were generally similar to those in women. In women back pain during the previous 12 months was weakly associated with height, and was significantly more common in those who reported frequent non-musculoskeletal symptoms such as headache and low mood. After adjustment for height and non-musculoskeletal symptoms, significant associations were found with frequency of manually moving patients around on the bed, manually transferring patients between bed and chair, and manually lifting patients from the floor. In contrast, no clear increase in risk was found in relation to transfer of patients with canvas and poles, manually lifting patients in and out of the bath, or lifting patients with mechanical aids. Confirmation of these findings is now being sought in a prospective study of the same population. CONCLUSIONS: This study confirms that low back pain is highly prevalent among nurses and is associated with a high level of sickness absence. People who often report non-musculoskeletal symptoms were significantly more likely to report low back pain. Specific manual handling tasks were associated with an increased risk of back pain; however, no such association was found with mechanised patient transfers.

Adult

Contrasting geographical distribution of mortality from pneumoconiosis and chronic bronchitis and emphysema in British coal miners.

To explore whether the characteristics of coal mine dust that predispose to chronic airways obstruction are the same as those associated with pneumoconiosis, mortality from the two disease was compared in coal miners in 22 counties of England and Wales during 1979-80 and 1982-90. The proportional mortality ratios (PMRs) for coal workers' pneumoconiosis varied from 135 (95% confidence interval (95% CI) 16-488) in Leicestershire to 3825 (95% CI 1538-7881) in South Glamorgan. The PMRs for chronic bronchitis and emphysema were consistently higher than those in other occupations, but showed much less geographical variation and did not correlate geographically with those for pneumoconiosis. These findings indicate that the pathogenetic mechanisms by which coal mine dust causes chronic bronchitis and emphysema depend on different features of the dust from those producing pneumoconiosis. Also, they suggest that current social security regulations in Britain, which require evidence of pneumoconiosis as a condition of compensation for chronic bronchitis and emphysema in coal miners, may discriminate unfairly against claimants from some regions.

Adult

The influence of increased bronchial responsiveness, atopy, and serum IgE on decline in FEV1. A longitudinal study in the elderly.

We have performed a 4-yr prospective survey of the association of allergen skin test positivity, total serum immunoglobulin E (IgE), and bronchial responsiveness to methacholine, with longitudinal decline in FEV1, in subjects over 65 yr of age. In 1987, 324 subjects completed a respiratory questionnaire, and underwent measurement of FEV1 and FVC, methacholine challenge, skin prick testing (to Dermatophagoides pteronyssinus, cat fur, mixed grasses, and Aspergillus fumigatus) and estimation of total serum IgE. After an interval of 4 yr, 212 subjects were reexamined. The mean annual decline in FEV1 was significantly higher in males than in females, but was not significantly influenced by smoking habits defined at the start of the study. The relation of atopy (skin test reaction to allergen > or = 3 mm greater than saline control), increased bronchial responsiveness (PD20FEV1 < or = 6.4 mumoles methacholine) and serum IgE > 80 IU/ml, to annual decline in FEV1 was examined for each risk factor individually with adjustment for age, sex, height, and initial FEV1, by multiple linear regression. Both atopy and bronchial responsiveness were significantly associated with accelerated decline in FEV1. Elevated IgE was correlated with faster FEV1 decline in subjects who were current smokers at the start of the study. In a multiple regression model examining the mutually adjusted associations of all relevant variables with annual decline in FEV1, male sex was the most important predictor (B = 38.6 ml/yr, 95% Cl = 4.3, 72.9). Increased bronchial responsiveness also tended to be associated with accelerated decline in FEV1. In further analyses incorporating the same variables, but restricted to specific smoking categories, age was the only significant factor in the never-smokers, whereas both atopy (B = 44.5 ml/yr, 95% Cl = 3.8, 85.3) and increased bronchial responsiveness (B = 43.5 ml/yr, 95% Cl = 4.6, 82.3) were significant predictors of accelerated FEV1 decline in former and current smokers combined.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Patterns of joint involvement in osteoarthritis of the hand: the Chingford Study.

OBJECTIVE: The hand is the major site of joint involvement in osteoarthritis (OA), but the clustering of this condition at different joint sites within the hand as part of an entity known as generalized OA remains contentious. We examine this issue in a population sample of 967 peri and postmenopausal women. METHODS: The pattern of radiographic involvement of hand joints was examined using the Kellgren and Lawrence system in a sample of women aged 45-64 years, selected from the general population in Chingford, East London. Log linear modelling techniques were used to examine clustering of OA in different joint sites and to examine whether this clustering remained significant after age adjustment. RESULTS: There was clear evidence of clustering in joint involvement: Thus 20 women had 4 or more affected joints compared with only 2 expected (chi 2 = 72.0, 4df, p < 0.001). The risk of multiple distal interphalangeal (DIP) joint involvement, after age adjustment, in a woman with a single affected DIP joint was significantly increased (OR 10.0, 95% CI 7.3-13.7) and was substantially greater than the corresponding risk for proximal interphalangeal joint (OR 3.1, 95% CI 1.4-6.8) involvement. Symmetry was the strongest determinant of pattern with an OR 38.8 (95% CI 14.5-103.5) for corresponding DIP joint involvement in the contralateral hand. CONCLUSION: These data provide clear evidence for a polyarticular subset of hand OA in women. There are 3 major determinants of the pattern of polyarticular involvement; symmetry, clustering by row and clustering by ray, in descending order of importance.

Female

Soft tissue sarcoma and non-Hodgkin's lymphoma in workers exposed to phenoxy herbicides, chlorophenols, and dioxins: two nested case-control studies.

We examined the effect of exposure to chemicals present in the production and spraying of phenoxy herbicides or chlorophenols in two nested case-control studies of soft tissue sarcoma and non-Hodgkin's lymphoma. Eleven sarcoma and 32 lymphoma cases occurring within an international cohort were matched for age, sex, and country of residence with 55 and 158 controls, respectively. Exposures to 21 chemicals or mixtures were estimated by three industrial hygienists who were blind to the subject's case-control status. Excess risk of soft tissue sarcoma was associated with exposure to any phenoxy herbicide [odds ratio (OR) = 10.3; 95% confidence interval (CI) = 1.2-91] and to each of the three major classes of phenoxy herbicides (2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, and 4-chloro-2-methylphenoxyacetic acid), to any polychlorinated dibenzodioxin or furan (OR = 5.6; 95% CI = 1.1-28), and to 2,3,7,8-tetrachlorodibenzo-p-dioxin (OR = 5.2; 95% CI = 0.85-32). Sarcoma risk was not associated with exposure to raw materials or other process chemicals. In the non-Hodgkin's lymphoma study, associations were generally weaker than those found in the study on sarcoma. These findings indicate that workers exposed to phenoxy herbicides and their contaminants are at a higher risk of soft tissue sarcoma.

Case-Control Studies

Lobar pneumonia: an occupational disease in welders.

We have used data from three analyses of occupational mortality for England and Wales to investigate a suspected hazard of pneumonia in welders. Mortality from the disease was consistently raised in welders aged 15-64, with standardised mortality ratios of 184 (95% CI 150-224) in 1959-63 and 157 (121-200) in 1970-72. Analysis of data for 1979-80 and 1982-90 showed that the increased risk is attributable mainly to an excess of pneumococcal and unspecified lobar pneumonia (proportional mortality ratio 255, 95% CI 192-332). No excess occurred in men above retirement age (65). A possible explanation of these findings is that welding fume reversibly increases the susceptibility of the lung to pneumonic infection. The observation of a similar mortality pattern in moulders and coremakers points to the metallic component of the fume as a possible culprit, but ozone or oxides of nitrogen could also be implicated. There are grounds for lobar pneumonia to be considered an occupational disease in welders.

Adolescent

Inflammatory bowel disease and domestic hygiene in infancy.

To test the hypothesis that Crohn's disease is caused by delayed exposure to enteric infections, we did a case-control study. We compared 133 patients who have Crohn's disease and 231 with ulcerative colitis who have controls selected from the general population and matched for age and sex. Crohn's disease was more common in subjects whose first houses had a hot-water tap (odds ratio 5.0, 95% CI 1.4-17.3) and separate bathroom (3.3, 1.3-8.3). Ulcerative colitis showed no clear relation to household amenities in infancy. These findings may explain why the incidence of Crohn's disease has increased in developed countries over the past 50 years.

Adolescent

Determinants of safe behaviour in farmers when working with pesticides.

Despite stringent regulation, accidents occur in the use of pesticides. To explore the factors which might influence farmers' approaches to safety when handling chemicals, we interviewed 84 agricultural workers from south-west Hampshire who reported having worked with pesticides in the previous 12 months. Most of those interviewed claimed that they always followed manufacturers' instructions regarding indications for use, method of application, mixing of chemicals, cleaning up and washing hands, but compliance was lower for recommendations about personal protective equipment and disposal of containers. Only 38% of subjects said that they always read all of the manufacturer's label when using a product for the first time. The main determinant of safe behaviour was the person's approach to safety in other situations, but formal training in the use of pesticides was also associated with more frequent use of personal protective equipment. Possession of a certificate of competence in pesticide use appeared to have less influence on working methods. Future efforts should be directed at changing farmers' handling of pesticides.

Adult

Epidemiological studies of styrene-exposed populations.

The potential human carcinogenicity of styrene has been investigated mainly by epidemiological studies of occupationally exposed populations. Several cohort studies have suggested that workers exposed to styrene in the chemical industry have increased mortality from lymphatic and hematopoietic cancer. However, this finding has not been consistent and has not been reproduced in studies of reinforced plastics manufacturers, whose exposures to styrene are generally higher. The explanation for the observed associations may therefore be confounding by concomitant exposures to other chemicals such as benzene and butadiene, which are not used in the reinforced plastics industry. Despite their large size, the published studies of mortality and cancer incidence lack the statistical power to rule out an important hazard from long-term exposure to high (> 50 ppm) airborne concentrations of styrene. However, they indicate that any risk of cancer from lower levels of exposure is likely to be small.

Humans

Cancer mortality in a historical cohort study of workers exposed to styrene.

OBJECTIVES: The goal of this study was to determine whether exposure to styrene is associated with an increased risk for neoplasms of the lymphatic and hematopoietic tissues. METHODS: A historical cohort study was conducted in Denmark, Finland, Italy, Norway, Sweden, and the United Kingdom. It involved 40,688 workers ever employed in the reinforced plastics industry, where high exposure to styrene occurs. Exposure to styrene was reconstructed through job histories and environmental and biological monitoring data. Cause-specific national death rates were used as the reference. Poisson regression was applied for internal comparisons. RESULTS: Among the exposed workers, no excess was observed for mortality from all neoplasms. Mortality from neoplasms of the lymphatic and hematopoietic tissues increased with time since first exposure and average level of exposure to styrene, but was not consistently associated with duration of exposure or with cumulative exposure. CONCLUSIONS: These findings leave open the possibility of an excess risk of neoplasms of the lymphatic and hematopoietic tissues among workers exposed to styrene.

Cohort Studies

Osteoarthritis of the hip: an occupational disease in farmers.

OBJECTIVE: To test the hypothesis that farmers are at high risk of hip osteoarthritis and to investigate possible causes for such a hazard. DESIGN: Cross sectional survey. SETTING: Five rural general practices. SUBJECTS: 167 male farmers aged 60-76 and 83 controls from mainly sedentary jobs. All those without previous hip replacement underwent radiography of the hip. MAIN OUTCOME MEASURES: Hip replacement for osteoarthritis or radiological evidence of hip osteoarthritis. RESULTS: Prevalence of hip osteoarthritis was higher in farmers than controls and especially in those who had farmed for over 10 years (odds ratio 9.3, 95% confidence interval 1.9 to 44.5). The excess could not be attributed to any one type of farming, and heavy lifting seems the likely explanation. CONCLUSIONS: Manual handling in agriculture should be limited where possible. Consideration should be given to making hip osteoarthritis a prescribed industrial disease in farmers. There may be wider implications for the prevention of hip osteoarthritis in the general population.

Age Factors