D. Choudat

Development of an asthma specific job exposure matrix and its application in the epidemiological study of genetics and environment in asthma (EGEA)

OBJECTIVES To develop a method suitable for estimating exposure risks in population studies of asthma from job titles and international codes, by combining a new job exposure matrix (JEM) with the expert judgement approach. The method was applied in the French epidemiological study of the genetics and environment in asthma (EGEA). METHODS The JEM contains 22 exposure groups including 18 high risk groups based on known risk factors for occupational asthma, divided into high molecular weight agents, low molecular weight agents, and mixed environments. After applying the JEM to job codes, exposure estimates for each subject were re-evaluated by examining job title texts. Three high risk exposure estimates for asthma were compared: firstly, applying the JEM to original codes (from different coders in each study centre); secondly, applying the JEM to revised codes (from one experienced coder); and thirdly, after reviewing JEM exposure estimates in the light of job title texts. RESULTS The study comprised 173 cases with asthma and 285 controls (age 18–65). Odds ratios (ORs) for asthma for high risk jobs were 1.0 (95% confidence interval (95% CI) 0.6 to 1.7), applying the JEM to original codes; 1.4 (95% CI 0.8 to 2.3), applying the JEM to revised codes; and 1.7 (95% CI 1.1 to 2.7), applying the JEM and subsequently re-evaluating exposure estimates from job title texts. Asthma ORs were 1.4 (95% CI 0.6 to 2.9) for high molecular weight agents, 2.3 (95% CI 1.2 to 4.4) for low molecular weight agents, and 2.1 (95% CI 0.9 to 5.2) for mixed environments. CONCLUSIONS This asthma JEM, when enhanced by expert re-evaluation of exposure estimates from job title texts, may be a useful tool in general population studies of asthma. In this study, a 1.7-fold increase in prevalence odds of high risk exposures was found among asthmatic workers compared with controls, with risk magnitude varying for different classes of exposure.

Consequences of occupational asthma on employment and financial status: a follow-up study

The aim of this study was to describe changes in employment and income following a diagnosis of occupational asthma, and to determine what factors might affect these changes. Two hundred and nine patients with occupational asthma were reviewed on average 3.1 yrs after the diagnosis had been made. They were contacted by telephone or were sent a self-administered questionnaire by post. Multiple logistic regression models were constructed to determine which variables were associated with loss of employment after the diagnosis. At the time of review, 44% of patients had left their previous job and 25% were currently unemployed. Remarkably, 32% remained exposed to the offending agents in the same job. Forty six percent of the patients had suffered a reduction of income (84% of those who had left their employer versus 19% of those still employed in the same company (p < 0.001)). Claims for compensation, size of the company, level of education, and age at the time of diagnosis were significantly associated with a risk for becoming unemployed or having a new employer after the diagnosis of occupational asthma. Occupational asthma results in severe socioeconomic consequences. The French compensation system for occupational asthma should be revised, as the criteria currently used to determine compensation for this disease largely underestimate the social and occupational damages.

Work-related asthma in France: recent trends for the period 2001–2009

Objective Knowledge on the time-course (trends) of work-related asthma (WRA) remains sparse. The aim of this study was to describe WRA trends in terms of industrial activities and the main causal agents in France over the period 2001–2009. Method Data were collected from the French national network of occupational health surveillance and prevention (Réseau National de Vigilance et de Prévention des Pathologies Professionnelles (RNV3P)). Several statistical models (non-parametric test, zero-inflated negative binomial, logistic regression and time-series models) were used and compared with assess trends. Results Over the study period, 2914 WRA cases were included in the network. A significant decrease was observed overall and for some agents such as isocyanates (p=0.007), aldehydes (p=0.01) and latex (p=0.01). Conversely, a significant increase was observed for cases related to exposure to quaternary ammonium compounds (p=0.003). The health and social sector demonstrated both a growing number of cases related to the use of quaternary ammonium compounds and a decrease of cases related to aldehyde and latex exposure. Conclusions WRA declined in France over the study period. The only significant increase concerned WRA related to exposure to quaternary ammonium compounds. Zero-inflated negative binomial and logistic regression models appear to describe adequately these data.

Occupational exposure to cleaning products and asthma in hospital workers

Objective Cleaning products may cause work-related asthma, but information regarding the specific exposures involved is scarce. We aimed to determine the associations between asthma and occupational exposure to cleaning agents in hospital workers. Methods Analyses were conducted in 179 (136 women) hospital workers and a reference population of 545 subjects (18–79 years) from the French case-control and familial Epidemiological study on the Genetics and Environment of Asthma (2003–2007). Exposures to cleaning agents were estimated using three methods: self-report, expert assessment and an asthma-specific job-exposure matrix (JEM). Associations between cleaning products and current asthma were evaluated by logistic regressions, stratified by sex and adjusted for age and smoking status. Results According to expert assessment, 55% of male and 81% of female hospital workers were exposed to cleaning/disinfecting tasks weekly (p<0.001). No association was observed between cleaning/disinfecting tasks and current asthma in men or in women whatever the assessment method used. In women, exposure to decalcifiers (expert assessment) was associated with current asthma (OR (95% CI):2.38 (1.06 to 5.33)). In hospital workers classified as exposed according to both the expert assessment and the JEM, additional associations were observed for exposure to ammonia (3.05 (1.19 to 7.82)) and to sprays with moderate/high intensity (2.87 (1.02 to 8.11)). Conclusions Female hospital workers are often exposed to numerous cleaning products, some of which were markedly associated with current asthma. Low numbers prevented a meaningful analysis in men. Objective and more accurate estimates of occupational exposure to cleaning products are needed to better understand the adverse effects of cleaning products.

Healthy worker effect and changes in respiratory symptoms and lung function in hairdressing apprentices

Aims: To compare the prevalence and incidence of respiratory symptoms and lung function values between hairdressing apprentices and office apprentices. Methods: A total of 322 hairdressing apprentices and 277 office apprentices (controls) were studied. Two cross sectional surveys were conducted in 1994 and 1996/97 with longitudinal follow up for a subgroup of apprentices (191 hairdressing apprentices and 189 office apprentices). Results: In the initial phase, the prevalence of respiratory symptoms was significantly lower among hairdressing apprentices than among office apprentices. Lung function test results showed significantly higher values for hairdressing apprentices. Non-specific bronchial reactivity was similar in the two groups. In the final phase, results for respiratory symptoms were similar. The incidence of respiratory symptoms was not significantly different between hairdressing apprentices and office apprentices. Subjects who dropped out had lower values for FVC and FEV1 in the initial phase than those who completed the final phase. There was a significant deterioration of FEV1 and FEF25–75% in hairdressing apprentices compared to office apprentices. There was a link between atopy and the incidence of most of the respiratory symptoms (day/night cough, wheezing, dyspnoea, mucosal hyperresponsiveness) and between smoking and the incidence of bronchial hyperreactivity. There was no significant correlation between change in lung function tests and specific hairdressing activities reported at the end of the apprenticeship or with environmental working conditions in hairdressing salons. Conclusions: Although a healthy worker effect can be suspected, results showed a significant deterioration of baseline values of lung function tests in the hairdressing apprentice group. However, no clear link was shown between change in lung function tests and specific parameters of occupational activities.

Under-estimation of self-reported occupational exposure by questionnaire in hospital workers

Objectives The aim of the study was to determine whether self-reported occupational exposure to cleaning/disinfecting agents in hospital workers is accurate, in comparison to expert assessment, taken to be the gold standard. Methods In the Epidemiological Study of the Genetics and Environment of Asthma (EGEA), participants were interviewed on occupation with a specific questionnaire for hospital workers regarding tasks and cleaning/disinfecting agents. Two estimates of exposure were available: self-report and expert assessment. The expert assessment involved a standardised procedure to estimate intensity, frequency and probability of exposure for each job. The present analysis focused on eight exposures: formaldehyde, glutaraldehyde, bleach/chlorine, alcohol, quaternary ammonium components, ammonia, sprays and latex gloves. Agreement and differences between self-reported and expert estimates were studied by kappa and phi coefficients and McNemar tests, respectively. Results In the survey of 1571 adults, 176 ever hospital workers (327 occupations) with both self-reported and expert exposure assessments were studied. An underestimation of self-reported exposure was observed especially for formaldehyde (26.5% vs 32.7%, p=0.01), ammonia (7.4% vs 18.8%, p<0.0001), alcohol (64.9% vs 93.0%, p<0.0001) and quaternary ammonium components (16.6% vs 70.9%, p<0.0001), compared to expert assessment. Conclusion Occupational exposure to disinfecting/cleaning agents is common and high in hospitals. A large underestimation of self-reported exposure and a lack of knowledge of product components was observed. Our results show the relevance of expert assessment in epidemiological studies to limit measurement bias. This work underlines the need for health education programmes on the occupational risks induced by these types of products.

Genetic differences in omega‐gliadins involved in two different immediate food hypersensitivities to wheat

Background:  Anti‐gliadin IgE are expressed in patients with food allergy associated to skin immediate hypersensitivity to hydrolyzed wheat proteins (IHHWP). It is not known if they react with ω5‐gliadins, the major allergens in wheat dependant exercise‐induced food anaphylaxis (WDEIA), encoded on wheat chromosomes 1B.

Employment status and socio-economic burden in systemic sclerosis: a cross-sectional survey

OBJECTIVE To assess employment status and socio-economic burden in SSc patients. METHODS Eighty-seven SSc patients (72 females), fulfilling the ACR or the Leroy and Medsger criteria, or both, were evaluated for employment status, socio-economic burden and handicap. Statistical analysis involved Mann-Whitney U-test and Fishers exact test and backward stepwise regression analysis. RESULTS In total, 60.9% of the SSc patients were on full-time sick leave and 35.6% were receiving a disability pension. On univariate analysis, myalgia was the only clinical manifestation more frequently encountered in sick-leave patients than others (73.6 vs 47.1%; P = 0.012). Karnofsky performance status (KPS) was lower in SSc patients who were on sick leave or were receiving a disability pension than others [78.5 (10.6) vs 85.8 (9.0); P = 0.004 and 78.1 (8.7) vs 83.1 (11.2); P = 0.016, respectively]. In addition, greater global, hand and mouth handicaps and depression were observed in patients on sick leave [HAQ 0.9 (0.7) vs 0.6 (0.5); P = 0.021; Cochin Hand Function Scale 21.7 (18.9) vs 10.7 (12.1); P = 0.003; mouth handicap scale 20.2 (10.8) vs 14.6 (10.0); P = 0.014; and depression dimension of the hospital anxiety and depression scale 7.1 (3.9) vs 4.8 (3.4); P = 0.003]. On multivariate analysis, factors associated with sick leave were KPS [odds ratio (OR) 0.92; 95%CI 0.88, 0.98] and myalgias (OR 3.19; 95% CI 1.19, 8.58), and the factor associated with receiving a disability pension was decreased income (OR 8.19; 95% CI 2.67, 25.12). CONCLUSIONS SSc patients commonly have to take full-time sick leave from work. Despite such patients receiving disability pensions, the socio-economic burden is considerable.

Do young adults with childhood asthma avoid occupational exposures at first hire

Information on the healthy worker hire effect in relation to asthma is scant. We aimed to assess whether and how childhood asthma-related characteristics (before hire) relate to occupational exposures at first hire. Analyses were conducted in 298 children examined at the first survey of the Epidemiological Study on the Genetics and Environment of Asthma (1991–1995), who reported a training period or a job at follow-up in 2003–2007 (aged 17–29 yrs; 53% males). Exposure likelihood to dust, gases and/or fumes in their first occupation was estimated by the ALOHA job exposure matrix. Asthma before the first occupation and two asthma classifications for severity (Global Initiative for Asthma 2002 guidelines) and symptoms were defined by questionnaire. In their first job, 47% of subjects were exposed. After adjustment (age, sex and education), pre-hire onset asthmatics (59%) were nonsignificantly less likely to be exposed (OR 0.67, 95% CI 0.41–1.11). Associations were stronger when considering those with severe asthma or high symptom score in childhood (OR 0.27 (95% CI 0.11–0.63) and OR 0.49 (95% CI 0.25–0.99), respectively). The association was observed in those who completed a university degree (OR 0.55, 95% CI 0.29–1.04) but not in the others (OR 0.98, 95% CI 0.44–2.22), with consistent results for all asthma characteristics. Results suggest a healthy worker hire effect in subjects with more severe or more symptomatic asthma in childhood. Education may modulate self-selection.

Effects of a combination of napping and bright light pulses on shift workers' sleepiness at the wheel: a pilot study

To assess the effects of napping + bright light on shift work drivers sleepiness at the wheel, we performed a pilot study on nine shift workers on three shifts (morning, afternoon, night), driving on a private road circuit. Sleepiness at the wheel was measured by ambulatory polysomnography and assessed using 30‐s segments of recordings with a percentage of theta electroencephalogram of at least 50% (15 s) of the period recorded. Sleepiness was also assessed by the Stanford Sleepiness Scale (SSS). Participants drove the same car on two similar 24‐h periods of work, with three drivers in each shift (morning, afternoon, night), separated by 3 weeks. During the baseline period, the subjects were told to manage their rest as usual. During the second experimental period, they had to rest lying in a dark room with two naps of 20 min and then exposed to bright light (5000 lux) for 10 min. Subjects showed a significantly decreased sleepiness at the wheel with an average of 10.7 ± 6.7 episodes of theta sleep during the baseline (766 ± 425 s) versus 1.0 ± 1.0 episode lasting 166 ± 96 s during the second period (P = 0.016; P = 0.0109). The percentage of driving asleep was also significantly reduced (3.7% ± 1.9% versus 0.9% ± 0.6%, P = 0.0077). The average SSS score in the group decreased from 2.76 ± 1.27 to 2.28 ± 0.74 (P = 0.09). In this pilot and preliminary study, a combination of napping and bright light pulses was powerful in decreasing sleepiness at the wheel of shift work drivers.