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Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

Background: Exposure to shift work has been associated with negative health consequences, although the association between shift work and sickness absence remains unclear. The aim of this study is to investigate associations between cumulative exposure to shift work and sickness absence among ground staff employees of an airline company. Methods: This study used data from the MORE (Monitoring Occupational Health Risks in Employees) cohort, which is a 5-year historic cohort. The population of the present study consisted of 7562 ground staff employees. For each employee, work schedules and sickness absence days between 2005 and 2009 were obtained from company records. For the exposure to different shift schedule types and to the cumulative number of night shifts, the association with long-term sickness absence (>7 consecutive sickness absence days) and the number of sickness absence episodes during 2009, was calculated using logistic and Poisson regression analyses. Socio-demographic variables, work-related variables, job classification variables, and previous sickness absence days were regarded as confounders. Results: After adjusting for previous sickness absence and job classification variables, only the group of employees that switched into working in a three-shift schedule, showed a significantly increased risk for long-term sickness absence (OR = 1.31, 95%CI 1.02-1.69). Night shift exposure was not significantly associated with long-term sickness absence. Exposure to shift work was negatively associated with more sickness absence episodes. Employees who were exposed to more than 46 night shifts also showed a lower risk for more sickness absence episodes. Subgroup analyses showed that single employees and employees without children had an increased risk for long-term sickness absence when exposed to a three-shift schedule, and when they had changed between shift schedule types. Conclusions: Cumulative exposure to shift work proved to be negatively associated with more sickness absence episodes, and was not associated with more long-term sickness absence, although selection bias could not be ruled out. Future research should explore the influence of household composition, and take into account both previous sickness absence and psychosocial and physical work factors to obtain a better estimation of the association between shift work and sickness absence.

Aim: To investigate differences in health perception and electromagnetic fields (EMF) between people within the general population reporting sensitivity or non-sensitivity to EMF, and people who registered themselves as sensitive to EMF at a non-governmental organisation (NGO). Methods: Correlations and regression analysis to compare a sample of the general population recruited via internet panel to individuals with idiopathic environmental intolerance to EMF (IEI-EMF) recruited via an interest group. Results: The general population sensitive group was more similar to the non-sensitive group in personal characteristics than to the NGO sensitive group. They experienced more – and more frequent – non-specific symptoms, reported higher perceived risk of EMF, and attributed their symptoms more to EMF than the non-sensitive group, but less than the NGO sensitive group. There was a positive association between attribution of symptoms to EMF and reported intensity of non-specific symptoms, which was stronger for the NGO sensitive subjects than for the general population. Conclusions: People sensitive to EMF and recruited via an internet panel differ from people sensitive to EMF and recruited via an NGO, who reported a higher frequency of non-specific symptoms. Attribution of symptoms to EMF is one of the predictors of the intensity of physical symptoms. Changing the perceived association between EMF and health problems in individuals with IEI-EMF might contribute to a better health experience.

Trust in government policy affects the way people perceive and handle risks. In our study, we investigated the relationships between trust in government policy regarding electromagnetic fields (EMF), perceived risk and perceived benefits of public and personal EMF sources, perceived control over exposure to EMF and responses to the possible EMF health risk (e.g. protest against placement of mobile phone base stations or power lines, or taking own measures against EMF exposure). Previous research indicated that perceived risk and benefits mediate the relationship between trust and peoples risk responses. Additionally, we suggest that perceived control over EMF exposure affects the relation between trust in government policy and perceived risk, and, consequently, the risk responses. We performed a survey among the Dutch population (n = 1009), which contained questions about risk responses to EMF, perceived risk and benefits of several EMF sources, trust in government policy and perceived control over EMF exposure. Comparing public EMF sources, i.e. power lines and mobile phone base stations, to personal EMF sources, i.e. microwave ovens and cordless and mobile phones, we tested our hypotheses. Variations in risk responses to both public and personal EMF sources were mainly explained by risk perception. In addition, perceived risk partially mediated the relationship between trust in government policy and risk responses. For public sources, perceived control over exposure weakened the negative relationship between trust and perceived risk. We conclude that, especially in people with low perceived control, a lack of trust in government policy may enhance perceptions of health risks, thereby increasing their inclination for risk responses. © 2013 Taylor & Francis Group, LLC.

Little attention has been devoted to the potential diversity in residents' health responses when exposed to an uncertain environmental health risk. The present study explores whether subgroups of residents respond differently to a new high-voltage power line (HVPL) being put into operation. We used a quasi-experimental prospective field study design with two pretests during the construction of a new HVPL, and two posttests after it was put into operation. Residents living nearby (0-300 m, n = 229) filled out questionnaires about their health and their perception of the environment. We applied latent class growth models to investigate heterogeneity in the belief that health complaints were caused by a power line. Classes were compared on a wide range of variables relating to negative-oriented personality traits, perceived physical and mental health, and perceptions of the environment. We identified five distinct classes of residents, of which the largest (49%) could be described as emotionally stable and healthy with weak responses to the introduction of a new power line. A considerable minority (9%) responded more strongly to the new line being activated. Residents in this class had heard more about the health effects of power lines beforehand, were more aware of the activation of the new line, and reported a decrease in perceived health afterwards. Based on our findings we can conclude that there is a considerable heterogeneity in health responses to a new HVPL. Health risk perceptions appear to play an important role in this typology, which has implications for risk management.

Screenshots of the mobile application used during the MORE Energy intervention. (PDF 1072Â kb)

Detailed explanation of all bugs that occured during the intervention period. (DOCX 16Â kb)

The way health risks of electromagnetic fields are portrayed in the media may shape public concerns that the growing exposure to electromagnetic fields in daily life constitutes a health hazard. We analysed the content of information on electromagnetic fields and health in Dutch media to identify aspects that might be linked to the public perception of electromagnetic fields. A systematic search was performed on archives of five major Dutch newspapers (from March 2008 to March 2010) and on the internet (in April 2010). Content analyses included the identification of main characteristics and the context or frame in which the information can be clearly understood. We identified 155 newspaper articles and 23 relevant websites. Analyses showed that the media content often suggested a negative relationship between electromagnetic field exposure and health but lacked detailed information about research, technical aspects, possible biological mechanisms and regulation policy. Regional media predominantly feature...

OBJECTIVE: This systematic review aims to summarize the available evidence to elucidate the effects of shift work, which includes night work, on body weight change. METHODS: A systematic search strategy using longitudinal studies was performed. Articles were included based on strict inclusion criteria; methodological quality was assessed by a standardized quality checklist. The results were summarized using a levels of evidence synthesis. RESULTS: The search strategy resulted in eight articles that met the inclusion criteria. Five of them were considered to be high- and three of them low-quality studies. Seven studies presented crude results for an association between shift work exposure and change in body weight: five high- and two low-quality studies. There was strong evidence for a crude relationship between shift work and body weight increase. Five studies presented weight-related outcomes adjusted for potentially relevant confounders (age, gender, bodyweight at baseline, and physical activity). Two studies found a significant difference between groups in the same direction. Consequently, the evidence for a confounders-adjusted relationship between shift work exposure and body weight was considered to be insufficient. CONCLUSIONS: Strong evidence for a crude association between shift work exposure and body weight increase was found. In order to further clarify the underlying mechanisms, more and better high quality studies about this subject are necessary.

Contains fulltext : 90661.pdf (Publisher’s version ) (Closed access) Given the inconsistent associations of cortisol with posttraumatic stress disorder (PTSD), analysis of basal functioning of the hypothalamic-pituitary-adrenal (HPA) axis in subjects frequently exposed to trauma and critical incidents with a range of PTSD symptomatology, may be valuable. In an epidemiological sample of 1880 police officers and firefighters, associations of salivary cortisol with PTSD, negative life events (NLE) and exposure to a major air disaster more than 8 years earlier, was explored. Probable PTSD was unrelated to cortisol level while past (>8 years earlier) and more recently experienced NLE were associated with lower cortisol levels even after adjustment for confounders. Disaster exposure interacted significantly with PTSD symptoms on cortisol level. In the disaster-exposed subgroup, PTSD symptomclusters of intrusion and hyperarousal (in particular sleep disturbances), were associated with lower and higher cortisol levels, respectively. A final model using backward elimination strategy, retained time of saliva sampling, smoking, gender, and NLE > 8 years earlier in the total sample, and additionally symptomclusters of intrusion and hyperarousal in the disaster-exposed subgroup. The final model explained 10% of the variance in cortisol. The findings are discussed in relation to literature on posttraumatic stress and basal functioning of the HPA-axis.

Objectives. To examine the relationships between exposure to the air disaster in Amsterdam and multiple physical symptoms among firefighters and police officers, and to explore the role of post-traumatic stress symptoms (PTSS) herein. Design. Historic cohort study. Methods. On average 8.5 years post-disaster, exposed professional firefighters (N = 334) and police officers (N = 834) and their nonexposed colleagues (N = 194 and N = 634, respectively) completed questionnaires on disaster exposure and current symptoms. Logistic regression with adjustment for background characteristics was used to compare exposed and nonexposed workers. PTSS were added to these models, as was the interaction between exposure and PTSS, to explore potential mediating and modifying effects, respectively. Results. Exposed workers reported multiple physical symptoms significantly more often. Multiple physical symptoms seemed to have particularly affected the exposed firefighters who rescued people, and the exposed police officers who supported injured victims and workers, who were involved in the identification of or search for victims and human remains, who witnessed the immediate disaster scene or had a close one affected by the disaster. These exposure effects were essentially independent of PTSS, and no significant interactions between exposure and PTSS were found. Conclusions. In conclusion, the excess in post-disaster multiple physical symptoms in exposed workers could not be attributed to PTSS. © 2008 The British Psychological Society.

Background. The Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess long-term health effects in professional assistance workers involved in the 1992 air disaster in Amsterdam. As part of ESADA indications of nephrotoxicity due to exposure to uranium from the balance weights of the crashed aircraft were assessed. Methods. Data of a historically defined cohort of 2499 (exposed and non-exposed) firefighters, police officers and hangar workers were collected 8.5 years after the disaster. Urinary uranium concentrations were determined by sector field inductively coupled plasma mass spectrometry. Urine albumincreatinine ratio and fractional excretion of beta(2)-microglobulin were calculated from a single-spot urine specimen and simultaneous blood sample. Exposed assistance workers were compared with their non-exposed colleagues, and associations between uranium and kidney function parameters were explored. Results. Median uranium concentrations were around 2 ng/g creatinine. Median values of albumincreatinine ratio and fractional excretion of beta(2)-microglobulin were well below the level for microalbuminuria and for tubular damage, respectively. No statistically significant differences between exposed and non-exposed workers were found in uranium concentrations and kidney function parameters, although exposed hangar workers had lower uranium concentrations. No statistically significant associations were found between uranium concentrations and kidney function parameters in the total cohort. Conclusions. Occupational exposure to the air disaster in Amsterdam was neither significantly associated with higher uranium concentrations, nor with disturbed kidney function parameters. In this large cohort of professional assistance workers, urinary uranium concentrations were in the low range compared with previously published reference populations. No indications of nephrotoxicity were found at urinary uranium concentrations around 2 ng/g creatinine.

Background: Shift work research has shown that the relationship between exposure to irregular working times and sickness absence may differ between working populations. Not much is known about the prevalence of sickness absence in flight crews or about the relationship between exposure to different flight schedules and sickness absence in this population. Aims: To examine the association between cumulative exposure to different flight types and sickness absence in flight crew members. Methods: The study population consisted of flight crew members from a 5 year historic cohort. Flight schedule and sickness absence data were obtained from company records. The association between the cumulative exposure to different flight types and sickness absence episodes of >7 days was determined using univariate and multivariate logistic regression analyses. Adjusted models were obtained by adding potential confounders. Previous sickness absence was added to compose the fully adjusted models. Results: The records of 8228 employees were analysed. The fully adjusted univariate analyses showed that the numbers of medium-haul flights and flights with time zone crossings were associated with an increase in the odds for sickness absence. The fully adjusted multivariate analyses showed no significant associations between flight types and sickness absence. Conclusions: Cumulative exposure to flight types was not independently associated with sickness absence in flight crew members when previous sickness absence was taken into account. Because sickness absence in the past can predict future absence, preventive strategies targeted at flight crew members with a history of high sickness absence may be effective.

BACKGROUND: In 1992 a cargo aircraft crashed into apartment buildings in Amsterdam. In the troublesome aftermath rumours emerged on potential toxic exposures and health consequences. The aim of this study is to assess the long-term impact of this disaster on the health-related quality of life (HRQoL) of professional assistance workers.METHODS: Historic cohort study, using questionnaires to assess occupational disaster exposure, HRQoL (SF36), and background variables, at on average 8.5 years post-disaster. Participating were the exposed professional firefighters (n = 334) and police officers (n = 834) who reported disaster-related task(s), and their non-exposed colleagues who did not report such tasks (n = 194, and n = 634, respectively).RESULTS: Multivariate logistic regression analysis showed that exposed workers reported a significantly lower physical HRQoL and vitality than non-exposed workers. Exposed police officers also reported a lower mental HRQoL. Among exposed workers, a lower HRQoL was reported significantly more often by workers who had a close one affected by the disaster; by firefighters who rescued people, cleaned-up, or witnessed the immediate disaster scene; and by police officers who supported the injured. Exposed police officers who perceived the disaster as 'not bad' reported a lower HRQoL less often than those to whom it was 'the worst ever'.CONCLUSIONS: This study demonstrates that professional disaster assistance workers are at risk for a lower HRQoL, even after years.

Confirmatory factor analyses were done to assess the dimensionality of the stress response in a sample of police officers and fire fighters (n = 1168) involved in the 1992 air disaster in Amsterdam. The confirmatory factor analyses were applied to the responses on two psychometrically different instruments, i.e., the Self-Rating Inventory for Posttraumatic Stress Disorder (SRIP) and the Impact of Event Scale (IES). The previously found distinction between (active) avoidance and numbing in samples highly affected by posttraumatic stress disorder appears to be applicable to the stress response of a less affected sample. For the SRIP, a five-factor structure (i.e., intrusion, avoidance, hyperarousal, emotional numbing and sleep disturbance) appeared to fit slightly better than the four-factor structures from previous findings. For the IES, our results replicated findings of a four-dimensional structure (i.e., intrusion, avoidance, numbing and sleep disturbance) underlying the posttraumatic stress response. The factors of the best-fitting structure of both instruments proved reliable. Due to the psychometric properties of the two instruments, the relationship between similar factors in both instruments was only low to moderate. Compared with the IES, factors of the SRIP were, however, less discriminative from other symptoms of psychopathology. Replication in different traumatized or community samples is recommended.

Background: In the aftermath of a cargo aircraft crash in Amsterdam in 1992, indications of autoimmune disorders appeared in some of the affected population. Methods: This epidemiologic study sought to determine the possible long-term autoimmune health effects of the aircraft disaster on professional assistance workers. Exposed professional firefighters (n=334) and police officers (n = 834) who performed at least 1 disaster-related task and hangar workers who sorted and investigated the wreckage (n=241) were compared with reference groups of nonexposed colleagues who did not perform any disaster-related tasks (n=194, n=634, and n=104, respectively). Data were collected a mean of 8.5 years after the disaster. Questionnaires were used to assess disaster-related tasks and 11 autoimmune-like symptoms. All serum samples were tested for the presence of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic and anticardiolipin antibodies. Results: Compared with nonexposed colleagues, exposed workers reported significantly more autoimmunelike symptoms. They reported the following symptoms significantly more often: tingling sensations, myalgia, loss of strength, easily fatigued, and a feeling of sand in the eyes (all groups); infection proneness (firefighters); skin abnormalities and nocturnal transpiration (police officers and hangar workers); and vasculitis-like symptoms and Raynaud discoloring (police officers). In contrast, we found no significant difference between exposed and nonexposed workers in autoantibody prevalence. Conclusion: Occupational exposure to the aircraft disaster resulted in an excess of long-term self-reported autoimmune-like symptoms in exposed professional assistance workers, but there was no difference between exposed and nonexposed workers in the prevalence of autoantibodies. ©2005 American Medical Association. All rights reserved.

The objective of this study was to compare sick leave data obtained from questionnaires with data from company records. During a period of 12 months, questionnaires were completed monthly for 6 months and then at 9 and 12 months. The sensitivity and specificity of questionnaires for detecting an episode of sick leave were determined, using the company records as a reference standard. In addition, the duration of sick leave episodes reported in the two data sets was compared. In this analysis, company records were not assumed to be superior, and agreement was assessed with intraclass correlation coefficients (ICCs). The sensitivity of questionnaires for detecting an episode of sick leave was 55% (95% CI = 0.50-0.60) and the specificity 83% (95% CI = 0.72-0.94). The ICC for all episodes was 0.58 (95% CI = 0.47-0.67). The only satisfactory ICC (0.87; 95% CI = 0.74-0.93) was found for the questionnaires at 9 and 12 months. No large systematic differences were found between the duration of episodes reported in the two data sets. In conclusion, in our study, the sensitivity of questionnaires for detecting an episode of sick leave was very low. Furthermore, when episodes were recalled, there was little agreement on the duration of the episode between questionnaire data and data in the company records. Based on these results and considering the risk of missing questionnaires, data on sick leave gathered from company records are clearly preferable as an outcome measure in research.

Background: There is public concern about the potential health effects of exposure to extremely low frequency electromagnetic fields (ELF-EMF) of high-voltage power lines (HVPLs). Some residents living near HVPLs believe ELF-EMF might cause non-specific health complaints. Objectives: The present study is the first to prospectively investigate whether self-reported health complaints and causal beliefs increase after the construction of a new power line. Methods: We used a quasi-experimental design with two pretests before and two posttests after a new HVPL was put into operation. Residents living near (0-300. m, n=229; 300-500. m, n=489) and farther away (500-2000. m, n=536) participated in the study. Linear mixed models were fitted to test whether symptom reports and beliefs that power lines caused health complaints increased more in residents living close to the new line compared to residents living farther away. Results: A significantly (. p

This study examined the use of health care by police officers after the air disaster in Amsterdam. On average 8.5 years post-disaster, involved police officers (n = 834, who reported disaster-related tasks), and their non-involved colleagues (n = 634) completed questionnaires on disaster involvement and health care in the preceding 12 months. Logistic regression showed that involved police officers more often used drugs on their own initiative, sleeping pills or tranquillisers, and consulted a general practitioner or medical specialist, a paramedical specialist, and a privately practicing psychologist or psychiatrist. Thus, even after years, police officers involved in disaster work may use more self-initiated health care. © The Author 2007. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Context. - Low back pain is a frequent and costly health problem. Prevention of low back pain is important bath for the individual patient and from an economic perspective. Objective. - To assess the efficacy of lumbar supports and education in the prevention of low back pain in industry. Design. - A randomized controlled trial with a factorial design. Setting. - The cargo department of an airline company in the Netherlands. Participants. - total of 312 workers were randomized, of whom 282 were available for the 6- month follow-up. Interventions. - Subjects were randomly assigned to 4 groups: (1) education (lifting instructions) and lumbar support, (2) education, (3) lumbar support, and (4) no intervention. Education consisted of 3 group sessions on lifting techniques with a total duration of 5 hours. Lumbar supports were recommended to be used during working hours for 6 months. Main Outcome Measures. - Low back pain incidence and sick leave because of back pain during the 6-month intervention period. Results. - Compliance with wearing the lumbar support at least half the time was 43%. In the 282 subjects for whom data were available, no statistically significant differences in back pain incidence (48 [36%] of 134 with lumbar support vs 51 [34%] of 148 without, P = .81) or in sick leave because of low back pain (mean, 0.4 days per month with lumbar support vs 0.4 days without, P = .52) were found among the intervention groups. In a subgroup of subjects with low back pain at baseline, lumbar supports reduced the number of days with low back pain per month (median, 1.2 vs 6.5 days per month; P = .03). Conclusions. - Overall, lumbar supports or education did not lead to a reduction in low back pain incidence or sick leave. The results of the subgroup analysis need to be confirmed by future research. Based on our results, the use of education or lumbar supports cannot be recommended in the prevention of low back pain in industry.

Background A considerable percentage of flight crew reports to be fatigued regularly. This is partly caused by irregular and long working hours and the crossing of time zones. It has been shown that persistent fatigue can lead to health problems, impaired performance during work, and a decreased work-private life balance. It is hypothesized that an intervention consisting of tailored advice regarding exposure to daylight, optimising sleep, physical activity, and nutrition will lead to a reduction of fatigue in airline pilots compared to a control group, which receives a minimal intervention with standard available information. Methods/design The study population will consist of pilots of a large airline company. All pilots who posses a smartphone or tablet, and who are not on sick leave for more than four weeks at the moment of recruitment, will be eligible for participation. In a two-armed randomised controlled trial, participants will be allocated to an intervention group that will receive the tailored advice to optimise exposure to daylight, sleep, physical activity and nutrition, and a control group that will receive standard available information. The intervention will be applied using a smartphone application and a website, and will be tailored on flight- and participant-specific characteristics. The primary outcome of the study is perceived fatigue. Secondary outcomes are need for recovery, duration and quality of sleep, dietary and physical activity behaviours, work-private life balance, general health, and sickness absence. A process evaluation will be conducted as well. Outcomes will be measured at baseline and at three and six months after baseline. Discussion This paper describes the development of an intervention for airline pilots, consisting of tailored advice (on exposure to daylight and sleep-, physical activity, and nutrition) applied into a smartphone application. Further, the paper describes the design of the randomised controlled trial evaluating the effect of the intervention on fatigue, health and sickness absence. If proven effective, the intervention can be applied as a new and practical tool in fatigue management. Results are expected at the end of 2013. Trial registration Netherlands Trial Register: NTR2722

OBJECTIVES: To determine the effectiveness of a weight-management program with personal counseling by phone or e-mail. METHODS: A randomized controlled trial of a 6-month program comparing two modes of intervention delivery (phone, n = 462; Internet, n = 464) with self-directed materials (control, n = 460), among overweight employees. Change in body weight after 2 years was the main outcome. RESULTS: Among complete cases, weight loss in the Internet group was 1.2 kg (95% confidence interval [CI], -1.9 to -0.4) and in the phone group 0.8 kg (95% CI, -1.5 to 0.03), compared with the control group. Multiple imputation of missing body weight resulted in comparative weight losses of -0.9 kg (95% CI, -2.0 to 0.3) and -0.4 kg (95% CI, -1.4 to 0.7). CONCLUSIONS: Among complete cases, the Internet intervention showed modest long-term weight loss, but among all participants neither program version was more effective than self-help. ©2011The American College of Occupational and Environmental Medicine.

Background Overweight (Body Mass Index [BMI] ≥ 25 kg/m2) and obesity (BMI≥ 30 kg/m2) are associated with increased cardiovascular risk, posing a considerable burden to public health. The main aim of this study was to investigate lifestyle intervention effects on cardiovascular risk factors in healthy overweight employees. Methods Participants were 276 healthy overweight employees (69.2% male; mean age 44.0 years [SD 9.2]; mean BMI 29.7 kg/m2 [SD 3.1]). They were randomized to one of two intervention groups receiving a six month lifestyle intervention with behavior counseling by phone (phone group) or e-mail (Internet group), or to a control group receiving usual care. Body weight, height, waist circumference, sum of skinfolds, blood pressure, total cholesterol level and predicted aerobic fitness were measured at baseline, at 6 and at 24 months. Regression analyses included the 141 participants with complete data. Results At 6 months a significant favorable effect on total cholesterol level (-0.2 mmol/l, 95%CI -0.5 to -0.0) was observed in the phone group and a trend for improved aerobic fitness (1.9 ml/kg/min, 95%CI -0.2 to 3.9) in the Internet group. At two years, favorable trends for body weight (-2.1 kg, 95%CI -4.4 to 0.2) and aerobic fitness (2.3 ml/kg/min, 95%CI -0.2 to 4.8) were observed in the Internet group. Conclusions The intervention effects were independent of the used communication mode. However short-term results were in favor of the phone group and long-term results in favor of the internet group. Thus, we found limited evidence for our lifestyle intervention to be effective in reducing cardiovascular risk in a group of apparently healthy overweight workers. Trial registration ISRCTN04265725

Background The work setting provides an opportunity to introduce overweight (i.e., Body Mass Index ≥ 25 kg/m2) adults to a weight management programme, but new approaches are needed in this setting. The main purpose of this study was to investigate the effectiveness of lifestyle counselling by phone or e-mail on body weight, in an overweight working population. Secondary purposes were to establish effects on waist circumference and lifestyle behaviours, and to assess which communication method is the most effective. Methods A randomized controlled trial with three treatments: intervention materials with phone counselling (phone group); a web-based intervention with e-mail counselling (internet group); and usual care, i.e. lifestyle brochures (control group). The interventions used lifestyle modification and lasted a maximum of six months. Subjects were 1386 employees, recruited from seven companies (67% male; mean age 43 (SD 8.6) y; mean BMI 29.6 (SD 3.5) kg/m2). Body weight was measured by research personnel and by questionnaire. Secondary outcomes fat, fruit and vegetable intake, physical activity and waist circumference were assessed by questionnaire. Measurements were done at baseline and after six months. Missing body weight was multiply imputed. Results Body weight reduced 1.5 kg (95% CI -2.2;-0.8, p < 0.001) in the phone group and 0.6 kg (95% CI -1.3; -0.01, p = 0.045) in the internet group, compared with controls. In completers analyses, weight and waist circumference in the phone group were reduced with 1.6 kg (95% CI -2.2;-1.0, p < 0.001) and 1.9 cm (95% CI -2.7;-1.0, p < 0.001) respectively, fat intake decreased with 1 fatpoint (1 to 4 grams)/day (95% CI -1.7;-0.2, p = 0.01) and physical activity increased with 866 METminutes/week (95% CI 203;1530, p = 0.01), compared with controls. The internet intervention resulted in a weight loss of 1.1 kg (95% CI -1.7;-0.5, p < 0.001) and a reduction in waist circumference of 1.2 cm (95% CI -2.1;-0.4, p = 0.01), in comparison with usual care. The phone group appeared to have more and larger changes than the internet group, but comparisons revealed no significant differences. Conclusion Lifestyle counselling by phone and e-mail is effective for weight management in overweight employees and shows potential for use in the work setting. Trial registration ISCRTN04265725.

No general, theoretical framework exists for exposure monitoring strategies for epidemiological purposes nor for the analysis of these data. It is, however, recognized that the variation in exposure over time and between workers is an important element of consideration in the design of measurement strategies and the analysis of exposure data. In this paper, the partitioning of exposure variability is discussed for two types of monitoring strategies. First, a monitoring strategy is considered in which all members of the study population are monitored on various occasions. In this strategy, the ratio of within and between worker variance gives information about the magnitude of underestimation of the exposure-response relationship. The second strategy discussed is one based on “homogeneous” exposure categories. This strategy is illustrated with a study among animal feed workers in The Netherlands. It is shown that the grouping which results from this strategy can be applied for epidemiological purp...

Objective. To identify subgroups of workers absent from work due to low back pain who are more or less likely to return to work earlier as a result of a graded activity intervention, and to investigate whether this intervention is effective in reducing pain-related fears and if so, whether these reductions in pain-related fears mediate return to work. Methods. A subgroup analysis was conducted on data from a previous randomized controlled trial of 134 Dutch airline workers, which found that a behaviorally-oriented graded activity intervention was more effective than usual care in stimulating return to work. The subgroup analyses added interaction terms to a Cox regression model that described the relationship between treatment allocation and return to work over 12 months of followup. Furthermore, we studied the effects of graded activity on pain-related fears and added variables indicating a reduction in pain-related fears to the model in order to investigate their influence on return to work. Results. Statistically significant interactions were found for disability, fear-avoidance beliefs about physical activity, and fear-avoidance beliefs about work. No indication was found that the reduction in pain-related fears in the graded activity group mediated more favorable return-to-work results in this group. Conclusion. Workers who perceive their disability to be moderate and workers with moderate scores for fear-avoidance beliefs return to work more rapidly as a result of the graded activity intervention than workers with higher scores. The return to work of workers receiving the graded activity intervention is possibly independent from the reductions in pain-related fears caused by this intervention. © 2008, American College of Rheumatology.

The objective of this study is to compare the costs and benefits of a graded activity (GA) intervention to usual care (UC) for sick-listed workers with non-specific low back pain (LBP). The study is a single-blind, randomized controlled trial with 3-year follow-up. A total of 134 (126 men and 8 women) predominantly blue-collar workers, sick-listed due to LBP were recruited and randomly assigned to either GA (N = 67; mean age 39 +/- 9 years) or to UC (N = 67; mean age 37 +/- 8 years). The main outcome measures were the costs of health care utilization during the first follow-up year and the costs of productivity loss during the second and the third follow-up year. At the end of the first follow-up year an average investment for the GA intervention of 475 euros per worker, only 83 euros more than health care utilization costs in UC group, yielded an average savings of at least 999 euros (95% CI: -1,073; 3,115) due to a reduction in productivity loss. The potential cumulative savings were an average of 1,661 euros (95% CI: -4,154; 6,913) per worker over a 3-year follow-up period. It may be concluded that the GA intervention for non-specific LBP is a cost-beneficial return-to-work intervention.

Objective: To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. Design and Setting: In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. Participants: Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. Main results: Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non-specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. Conclusions: The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.

BACKGROUND: On 4 October 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, the Netherlands. Fire-fighters and police officers assisted with the rescue work.OBJECTIVES: To examine the long term health complaints in rescue workers exposed to a disaster.METHODS: A historical cohort study was performed among police officers (n = 834) and fire-fighters (n = 334) who performed at least one disaster related task and reference groups of their non-exposed colleagues (n = 634 and n = 194, respectively). The main outcome measures included digestive, cardiovascular, musculoskeletal, nervous system, airway, skin, post-traumatic stress, fatigue, and general mental health complaints; haematological and biochemical laboratory values; and urinalysis outcomes.RESULTS: Police officers and fire-fighters who were professionally exposed to a disaster reported more physical and mental health complaints, compared to the reference groups. No clinically relevant statistically significant differences in laboratory outcomes were found.CONCLUSIONS: This study is the first to examine long term health complaints in a large sample of rescue workers exposed to a disaster in comparison to reference groups of non-exposed colleagues. Findings show that even in the long term, and in the absence of laboratory abnormalities, rescue workers report more health complaints.

Background In 1992 a cargo aircraft crashed into a residential area of Amsterdam. A troublesome aftermath followed, with rumors on potential toxic exposures and health consequences. Health concerns remained even though no excess morbidity was predicted in retrospective risk evaluations. This study aimed to assess to what extent the rescue workers attribute long-term physical complaints to this disaster, including its aftermath, and to examine associations between such attribution and types of exposure and background variables. Methods Historic cohort study that collected questionnaire data on occupational disaster exposure, attribution of physical complaints, and background variables on average 8.5 years post-disaster. For the present study the workers who were exposed to the disaster were selected from the historic cohort, i.e. the professional firefighters (n = 334), police officers (n = 834), and accident and wreckage investigators (n = 241) who performed disaster-related tasks. Results Across the three occupational groups, a consistent percentage (ranging from 43% to 49%) of exposed workers with long-term physical complaints attributed these to the disaster, including its aftermath. Those with more physical complaints attributed these to a stronger degree. Multivariate logistic regression analyses showed that attribution was significantly more often reported by firefighters who rescued people, and by police officers who reported the identification and recovery of or search for victims and human remains, clean-up, or security and surveillance of the disaster area; who witnessed the immediate disaster scene; who had a close one affected by the disaster; and who perceived the disaster as the worst thing that ever happened to them. Age, sex and educational level were not significantly associated with attribution. Conclusion This study provides further cross-sectional evidence for the role of causal attribution in post-disaster subjective physical health problems. After on average 8.5 years, almost a third (32%) of all the exposed workers, and almost half (45%) of the exposed workers with physical complaints, attributed these complaints to the disaster, including its aftermath. The similarity of the results across the occupational groups suggests a general rather than an occupation-specific attribution process. Longitudinal studies are needed to determine whether causal disaster attribution leads to persistence of post-disaster complaints and health care utilization.

Introduction: Behaviorally oriented graded activity interventions have been suggested for sick-listed workers with low back pain on return to work, but have not been extensively evaluated. Methods: One hundred and thirty-four workers were randomly assigned to either a graded activity intervention (n = 67) or usual care (n = 67) and followed-up for 12 months. Results: The graded activity group returned back to work faster with a median of 54 days compared to 67 days in the usual care group. The graded activity intervention was more effective after approximately 50 days post-randomization (HRR = 1.9, CI = 1.2-3.1, p = 0.01). Differences between the groups in number of recurrent episodes, total number of days of sick leave due to low back pain, and total number of days of sick leave due to all diagnoses, were in favor of the graded activity group, although not statistically significant. No effects of the graded activity intervention were found for functional status or pain. Conclusion: Graded activity intervention is a valuable strategy to enhance short-term return to work outcomes. © 2005 Springer Science + Business Media, Inc.

The effectiveness of return-to-work intervention for subacute low-back pain on work absenteeism, pain severity, and functional status was examined by means of a systematic review of randomized controlled trials. Publications in English that met the selection criteria were identified in a computer-aided search and assessed for methodological quality. A best-evidence synthesis was performed instead of statistical data pooling, because of the heterogeneity of the interventions and study populations. Five of nine studies comparing return-to-work intervention with usual care were identified as methodologically high-quality studies. Strong evidence was found for the effectiveness of return to work intervention on the return-to-work rate after 6 months and for the effectiveness of return-to-work intervention on the reduction of days of absence from work after > or = 12 months. It can be concluded that return-to-work interventions are equal or more effective regarding absence from work due to subacute low-back pain than usual care is.

Background In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. Methods/Design Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. Discussion In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers.

Background: Long-term health consequences of disasters have not been studied extensively, one reason amongst others is that no pre-disaster observation is available. This study focuses on an aeroplane crash on an Amsterdam suburb. The ongoing Longitudinal Aging Study Amsterdam has one pre-disaster and several post-disaster observations, making it possible to study changes in health, taking pre-disaster health characteristics into account. Methods: Three exposure groups are distinguished: those living within a radius of 1km from the disaster (initial n = 39), those living between a radius of 1 and 2km from the disaster (initial n = 56), and those living in the rest of the city of Amsterdam (initial n = 508). Health measures include general health, health in comparison with age peers, functional limitations, disability and cognitive functioning. These measures are based on self-ratings, interviewer observations, or both. Results: Older persons living closest to the disaster area are likely to experience health decline in the wake of a disaster, over and above the health decline that would occur normally with aging. The disaster-associated health decline is small, and most obvious in the ability to perform actions (such as mobility), but is not observed in either disability in daily functioning, nor in self-perceptions of health. Cognitive functioning even shows a short-term improvement. Conclusion: These findings suggest substantial resilience in older adults, despite their common health problems. © The Author 2005. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

BACKGROUND: Low back pain is a common medical and social problem frequently associated with disability and absence from work. However, data on effective return to work after interventions for low back pain are scarce.OBJECTIVE: To determine the effectiveness of a behavior-oriented graded activity program compared with usual care.DESIGN: Randomized, controlled trial.SETTING: Occupational health services department of an airline company in the Netherlands.PATIENTS: 134 workers who were absent from work because of low back pain were randomly assigned to either graded activity (n = 67) or usual care (n = 67).INTERVENTION: Graded activity, a physical exercise program based on operant-conditioning behavioral principles, to stimulate a rapid return to work.MEASUREMENTS: Outcomes were the number of days of absence from work because of low back pain, functional status (Roland Disability Questionnaire), and severity of pain (11-point numerical scale).RESULTS: The median number of days of absence from work over 6 months of follow-up was 58 days in the graded activity group and 87 days in the usual care group. From randomization onward, graded activity was effective after 50 days of absence from work (hazard ratio, 1.9 [95% CI, 1.2 to 3.2]; P = 0.009). The graded activity group was more effective in improving functional status and pain than the usual care group. The effects, however, were small and not statistically significant.CONCLUSIONS: Graded activity was more effective than usual care in reducing the number of days of absence from work because of low back pain.

The study describes results of the first part of a follow-up study among 50 animal feed and grain elevator workers. The initial results suggest that the change in lung function over a 5 year period is related to the dust exposure. Workers in the high exposure category showed a greater decline in lung function than workers in the low exposure category. The decline in lung function was strongest for workers who were low exposed at the beginning of the study and who became high exposed during the follow-up period.

Low back pain is a major medical and social problem associated with disability, work absenteeism and high costs. Given the impact of the problem, there is a need for effective treatment interventions in occupational healthcare that aim at the prevention of chronic disability and the realisation of return to work. These so-called return-to-work (RTW) interventions are becoming increasingly popular. As well as questions concerning the effectiveness of RTW interventions, there are also important questions on the actual content and underlying concepts of these multifactorial intervention strategies. The purpose of this review is to examine the literature on the content and underlying concepts of RTW interventions for low back pain. A systematic literature search identified 14 randomised controlled trials (RCTs) evaluating the effects of 19 RTW interventions. The content and concepts of these RTW interventions are described, compared and discussed in this review. Further, the contents of the RTW interventions are classified by the use of predefined components (physical exercises, education, behavioural treatments and ergonomic measures). The identified RTW interventions varied with respect to the disciplines involved, the target population and the number and duration of sessions. The classification showed that physical exercises were a component of most of the selected interventions, followed by education, behavioural treatments and ergonomic measures. The most prevalent combination of components was the combination of physical exercises, behavioural treatment and education. However, the types of physical exercises, behavioural treatment and education varied widely among the RTW interventions. The described concepts for the physical exercises were an increase of muscle strength, coordination, range of motion of the spine and cardiovascular fitness, and a decrease of muscle tension. Education as a part of RTW interventions is believed to increase the understanding of patients regarding their disorder and treatment. Behavioural treatments were mainly based on the gate control theory of pain (psychophysiological processes are involved in pain perception) and/or the operant conditioning hypothesis (pain behaviour is determined by its consequences). No concepts were described for ergonomic measures. Finally, the plausibility of the described concepts is discussed. Future RCTs on this topic should evaluate the underlying concepts of the RTW intervention in addition to its effectiveness.

The benefits of using linear mixed-effects models for occupational exposure assessment were studied by re-analysing three data sets from two published surveys with repeated exposure measurements. The relative contributions of particular characteristics affecting exposure levels were assessed as in a multiple regression model, while controlling for the correlation between repeated measurements. While one-way ANOVA allows one only to estimate unconditioned variance components, a mixed model enables estimation of between- and within-worker variance components of exposure levels while accounting for the fixed effects of work characteristics. Consequently, we can identify the work characteristics affecting each variance component. Mixed models were applied to the data sets with repeated measurements and auxil iary information on work characteristics. The between-worker variance components were reduced by 35, 66 and 80%, respectively, in the three data sets when work characteristics were taken into account. The within-worker (day-to-day) variability was reduced only in the pig farmer data set, by 25%, when accounting for work activities. In addition, coefficients of work characteristics from the mixed model were compared with coefficients resulting from originally published multiple linear regression models. In the rubber manufacturing data, the coefficients of the mixed model showed similar relative importance, but were generally smaller than the coefficients from regression models. However, in the pig farm data, only the coefficients of work activities were somewhat reduced. The mixed model is a helpful tool for estimating factors affecting exposure and suitable variance components. Identifying the factors in the working environment that affect the between-worker variability facilitates a posteriori grouping of workers into more uniformly exposed groups. Identifying the factors that affect the within-worker variance is helpful for hazard control and in designing efficient sampling schemes with reference to time schedule.

Study Design. A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. Objective. To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. Summary of Background Data. A restriction of trunk motion and a reduction in required back muscle forces in lifting are two proposed mechanisms of action of lumbar supports. Available studies on these putative mechanisms of action of lumbar supports have reported contradictory results. Methods. A literature search for controlled studies on mechanisms of action of lumbar supports was conducted. The methodologic quality of the studies was assessed. The evidence for the two proposed mechanisms of action of lumbar supports was determined in meta-analyses. Results. Thirty-three studies were selected for the review. There was evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending, with overall effect sizes of 0.70 (95% confidence interval [Cl] 0.39-1.01) and 1.13 (95% Cl 0.17-2.08), respectively. The overall effect size for rotation was not statistically significant (0.69; 95% Cl -0.40-4.31). There was no evidence that lumbar supports reduce the electromyogram activity of erector spinae muscles (effect size of 0.09; 95% Cl -0.41-0.59) or increase the intra-abdominal pressure (effect size of 0.26; 95% Cl -0.07-0.59). Conclusion. There is evidence that lumbar supports reduce trunk motion for flexion-extension and latera bending. More research is needed on the separate outcome measures for trunk motion before definite conclusions can be drawn about the work conditions in which lumbar supports may be most effective. Studies of trunk motion at the workplace or during specified lifting tasks would be especially useful in this regard.

Objective - To assess the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry. Methods - A computerised search for controlled clinical trials was conducted. A criteria list was used to assess the methodological quality of the studies. The available evidence for the effectiveness of the interventions was graded with a rating system for the level of evidence. Effect sizes of individual studies were combined if the studies were sufficiently similar. Results - 11 studies were identified for the review. The methodological quality of all studies was low, with a maximum score of three out of seven for internal validity. There was no evidence for the effectiveness of lumbar supports due to contradictory outcomes of the studies. Five of the six studies on education reported no effect. Thus there is limited evidence that education does not help to prevent back pain. All three studies on exercise reported a positive result, indicating limited evidence for the effectiveness of exercise. The combined effect size for exercise was 0.53, which is a medium sized effect. Conclusions - Although widely used, there is little evaluative research on the preventive measures studied here. The review showed that there is limited evidence that exercise has some effect in the prevention of back pain and that education is not effective. No conclusive evidence was found for or against the effectiveness of lumbar supports. Research of higher methodological quality is needed before firm conclusions on the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry can be drawn.