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Purpose The objective of this study is to investigate the effect of a Self-Management Program for workers with a chronic disease. This program is based on the Chronic Disease Self-Management Program of Stanford University, modified for workers with a chronic somatic disease. Methods In a randomized controlled trial, the effectiveness of a Self-Management Program was evaluated. Participants were randomly assigned to the experimental group (n = 57) and the control group (n = 47). The experimental group received an intervention, the control group received care as usual. Primary outcome measures were self-efficacy at work and the attitude towards self-management at work. Secondary outcomes were the SF-12 health survey questionnaire, job satisfaction and intention to change job. The results were measured at baseline, after the intervention and 8 months after the intervention. Results The attitude towards self-management at work (enjoyment) improved after 8 months for the intervention group ( p = 0.030). No other outcome variable differed significantly. As an interaction effect, it was found that low educated workers developed a better physical health quality (SF-12) in the intervention group compared with the control group. The attitude towards self-management at work (importance) improved in the intervention group for older and female workers and the attitude toward enjoying self-management at work improved for female workers only. Conclusion The results show that low educated workers, older workers and women benefit significantly more from the training than higher educated workers, younger workers and men. [ABSTRACT FROM AUTHOR]

Purpose: To study the course and consequences of work-related upper extremity disorders in the registry of the Netherlands Centre for Occupational Diseases (NCvB). Methods: A follow-up study was performed in a sample of consecutive cases of work-related upper extremity disorders notified to the NCvB. Perceived severity was measured with VAS (0-100), quality of life with VAS (0-100) and SF-36, functional impairment with DASH and sickness absence with a questionnaire. Measurements took place directly after notification (T0) and after 3, 6 and 12 months (T1-T3). A linear mixed model was used to compare scores over time. Results: Average age of the 48 consecutive patients (89% response) was 42 years; 48% were men. Perceived severity, functional impairment and sickness absence decreased statistically significant during the follow-up period, and quality of life scores improved. Patients older than 45 years scored worse on perceived severity of the disease, functional impairment and quality of life than did younger patients. Conclusions: The role of registries of occupational diseases for preventive policy can be extended by creating longitudinal data in sample projects. In the sample from our registry, work-related upper extremity disorders had a favourable course. [ABSTRACT FROM AUTHOR]

Background: Rheumatic diseases are a major cause of permanent work disability. In the process of occupational rehabilitation several health professionals may have a role.Objective: To assess the quality and quantity of communication and cooperation between Dutch rheumatologists and occupational physicians.Methods: A postal survey among 187 Dutch rheumatologists.Results: 153/187 rheumatologists (82%) returned the questionnaire. They considered reducing pain and fatigue to be their major responsibility in the process of occupational rehabilitation, followed by improving work participation (68/153 (44%)) and quality of work (55/153 (36%)). Although 112/153 (73%) of the rheumatologists judged the communication and cooperation with occupational physicians as reasonable to good, 119/153 (78%) of them were willing to improve the collaboration. Perceived bottlenecks mentioned were a lack of clarity about the occupational physician's position and activities, and the absence of practice guidelines. The most important prerequisites for improvement were found to be guarantees about the occupational physician's professional independence and more clarity about the competence of the occupational physicians and how they used the information provided.Conclusion: Dutch rheumatologists are willing to improve cooperation and communication with occupational physicians. The perceived lack of clarity about their mutual tasks appears to be a major obstacle. Thus the development of a joint education programme and a guideline for occupational rehabilitation in rheumatic diseases may be appropriate first steps towards improvement. [ABSTRACT FROM AUTHOR]

Periodic Occupational Health Surveys (POHS) are frequently used by occupational health and safety services in the Netherlands as a risk assessment instrument. These surveys include a questionnaire on work and health. Systematic attention is paid in this questionnaire to a broad range of working conditions and health complaints. In this article a method is presented to identify and evaluate work risks and health problems in groups of workers. Working conditions and health in any given company or department are assessed by comparing questionnaire data from its worker populations with data from one or more reference populations. Significant differences are interpreted as signals for both adverse working conditions and health problems. Considerations and choices with regard to the technical, operational and strategic quality of the method are elucidated. Probabilities of α- and β-errors, choice of significance levels, and selection of reference populations are dealt with. Finally, a way of presentation of the results is shown. The method is considered to be part of a broader approach toward risk assessment. We recommend the combined use of questionnaire results and other available information, such as workplace surveys and sickness absence data. Questionnaires about work and health can be seen as one step in a multi-phase design: like in many diagnostic processes, the latter phases can enhance the precision of previous results. Recommendations are made for validating and evaluating this instrument. [ABSTRACT FROM AUTHOR]

Objectives: To investigate cooperation between occupational physicians (OPs) and general practitioners (GPs).Methods: Literature review; structured interviews; questionnaires sent to randomised samples of OPs (n = 232) and GPs (n = 243).Results: Actual cooperation is poor. However, more than 80% of both groups responded that they want to improve their cooperation, aiming at better quality of care. Obstacles identified by OPs include insufficient knowledge among GPs about occupational health services (OHSs) (57%) and their patients' working conditions (52%). OPs also consider that GPs suspect them of serving employers more than employees (44%) and of verifying reasons of absence, with information from GPs (34%). Responses from GPs confirm these two suspicions (48%, response 58%), adding obstacles like commercialisation of OHS, lack of financial incentives, etc. Both groups are unanimous about prerequisites for improvement, especially guaranteeing the professional autonomy of OPs (OPs 86%, GPs 76%).Conclusion: As a first step to overcome obstacles to cooperation, OPs must clarify their position to GP colleagues. Initiatives have been taken after presenting this study. [ABSTRACT FROM AUTHOR]

Objectives: To assess if the implementation of guidelines for occupational rehabilitation of patients with low back pain by means of process variables--a set of objective criteria for technical performance and continuity of care--led to a better outcome in clinical and return to work variables.Methods: The study group consisted of 59 patients with at least 10 days of sick leave because of low back pain. Univariate analyses as well as multiple logistic regression and Cox's regression analyses were performed to assess the relation between quality of care and outcome.Results: Process indicators for technical competence, continuity of care, and total performance were all significantly related to satisfaction of employees. Continuity of care and total performance were significantly related to working status at 3 months, and time to return to work. None of the process indicators was related to pain or disability after 3 months follow up. Satisfaction was not related to any of the other outcome variables. This indicates that if guidelines for occupational rehabilitation are met, outcome is better.Conclusion: Quality of the process of care was related to outcome. Interventions of occupational physicians need improvement in the areas of continuity of care and communication with treating physicians. The effectiveness of an improved intervention should be studied in a subsequent randomised clinical trial. [ABSTRACT FROM AUTHOR]

Objectives: To (a) describe differences in the outcome of cross sectional and longitudinal analysis on musculoskeletal complaints relative to age and work demands, and (b) to assess the entrance and drop out selection on musculoskeletal complaints among groups of employees relative to age and work demands.Methods: A study population was selected on the basis of questionnaire data from periodical occupational health surveys of almost 45,000 employees collected between 1982 and 1993. From all companies within this data base that participated twice in company wide surveys four years apart, male employees were selected, and stratified for age and work demands. There were several populations: follow up (participation in both surveys); drop out (participation only in the first survey); entrance (participation only at the second survey); and two cross sectional populations (all participants at each survey). Prevalences of back complaints and turnover rates were analysed.Results: Reported back complaints in the cross sectional analysis declined over the oldest age groups in heavy physical work versus a small increase in the longitudinal analysis. The age group 50-9 and back complaints were identified as predictors at the first survey for not participating at the second survey. Neither age nor work demands at the first survey indicated drop out among those employees with back complaints at the first survey. The effects of entrance selection on estimated prevalences were small.Conclusions: The results indicate that musculoskeletal disorders lead to selection out of work, affecting the validity of both cross sectional and longitudinal epidemiological studies. In future studies analyses of turnover figures on musculoskeletal complaints relative to work demands and age are recommended. [ABSTRACT FROM AUTHOR]

Objectives: To achieve a coherent programme of topics for research in occupational health and safety, with well founded priorities and to relate them to perceived gaps and needs in The Netherlands.Methods: In the first phase of the study 33 key informants were interviewed. In the second phase questionnaires were sent to 150 Dutch experts (including the key informants). Four groups were recruited, originating from: occupational health and safety services; scientific research institutes; governmental and other administrative bodies; and companies. Using the Delphi technique, the experts were asked to prioritize several topics, which were placed under different headings. In the third phase five workshops were organised to elaborate on the highly prioritized topics.Results: The response rates were 86% for the first and 81% for the second questionnaire. In the second round consistency was reached and consensus proved to be satisfactory; so that the Delphi process was stopped. There were surprisingly few differences in opinion between the four groups. The most important heading was "design/implementation/evaluation of measures", in which the topic cost-benefit analysis of measures had the highest score. "Assessment of relations between exposure and effect" was the second most important heading. Under this heading, topics on work stress were generally judged to be more important than topics on safety and biological, chemical, and physical hazards. The headings "occupational rehabilitation/sociomedical guidance" and "occupational health care/occupational health services" had about the sam priority, closely following the heading "assessment of relations between exposure and effect".Conclusions: The general agreement on priorities should provide a sufficiently broad basis for decision makers to initiate a long term programme for occupational health research and development in The Netherlands. [ABSTRACT FROM AUTHOR]

Guidelines for occupational rehabilitation of workers with low-back pain were developed as part of a larger study. We have formulated criteria for good practice of occupational rehabilitation on the basis of these guidelines. To assess the quality of occupational rehabilitation in the Netherlands, these criteria were subsequently used in an audit of medical records. The number of patients who received care consistent with the guidelines was compared to the number of patients eligible to receive that kind of care (performance rate). Six performance rates were calculated from the medical files of 40 workers with 48 new episodes of low-back pain. Two performance rates proved to be below 25% and two almost 50%. The highest performance rate, that for curative policy, was 90%. These results are discussed in the light of the reliability of the original data. We recommend construction of guidelines as well as reliable registration of the occupational rehabilitation process to increase the possibilities of auditing and to raise the quality of occupational health care. [ABSTRACT FROM PUBLISHER]

Background: Germline data have become widely available in paediatric oncology since the introduction of paired tumour-germline sequencing. To guide best practice in cancer predisposition syndrome (CPS) diagnostics, we aimed to assess the diagnostic yield of extensive germline analysis compared with clinical selection-based genetic testing among all children with cancer., Methods: In this prospective diagnostic study, all children (aged 0-19 years) with newly diagnosed neoplasms treated in the Netherlands national centre, the Princess Máxima Center for Pediatric Oncology (Utrecht, Netherlands), between June 1, 2020, and July 31, 2022, were offered two approaches to identify CPSs. In a phenotype-driven approach, paediatric oncologists used the McGill Interactive Pediatric OncoGenetic Guidelines tool to select children for referral to a clinical geneticist, and for genetic testing. In a phenotype-agnostic approach, CPS gene panel sequencing (143 genes) was offered to all children. In children declining the research CPS gene panel, 49 CPS genes were still analysed as part of routine diagnostics by the pathologist. Children with a causative CPS identified before neoplasm diagnosis were excluded. The primary objective was to compare the number and type of patients diagnosed with a CPS between the two approaches., Findings: 1052 children were eligible for this study, of whom 733 (70%) completed both the phenotype-driven approach and received phenotype-agnostic CPS gene panel sequencing (143 genes n=600; 49 genes n=133). In 53 children, a CPS was identified: 14 (26%) were diagnosed by the phenotype-driven approach only, 22 (42%) by CPS gene sequencing only, and 17 (32%) by both approaches. In 27 (51%) of the 53 children, the identified CPS was considered causative for the child's neoplasm. Only one (4%) of the 27 causative CPSs was missed by the phenotype-driven approach and was identified solely by phenotype-agnostic CPS gene sequencing. In 26 (49%) children, a CPS with uncertain causality was identified, including 14 adult-onset CPSs. The CPSs with uncertain causality were mainly detected by the phenotype-agnostic approach (21 [81%] of 26)., Interpretation: Phenotype-driven genetic testing and phenotype-agnostic CPS gene panel sequencing were complementary. The phenotype-driven approach identified the most causative CPSs. CPS gene panel sequencing identified additional CPSs, many of those with uncertain causality, but some with clinical utility. We advise clinical evaluation for CPSs in all children with neoplasms. Phenotype-agnostic testing of all CPS genes is preferably conducted only in research settings and should be paired with counseling., Funding: Stichting Kinderen Kankervrij., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Following an audit, the flexible assertive community treatment-teams (FACT-teams), in Winterswijk, the Netherlands, set out to discover a more recovery-oriented approach to treatment and monitoring. Their findings support researching four recovery phases described previously.
AIM: A pilot-study to investigate the possibilities to create a more recovery-oriented working method by applying the four recovery phases - ranging from being overwhelmed by the condition to living past the condition - in FACT-teams.
METHOD: The FACT-teams started to monitor patients during the recovery phases and developed a semi-structured interview that can be used to determine the current recovery phase. After the phase has been determined, a plan is written on how to progress to the next phase.
RESULTS: Monitoring during the recovery phases proved to be useful in showing both succesfull and stagnating treatments. The recovery phases also became part of the standard treatment plans in the electronic patient dossier. An important result of this project was the recovery-oriented interview we developed.
CONCLUSION: Monitoring and interviewing based on the four recovery phases subjectively leads to more in-depth and more recovery-oriented evaluations of treatment. More empirical research into this method is necessary.

Purpose: Working in conditions with daily exposure to organic solvents for many years can result in a disease known as chronic solvent-induced encephalopathy (CSE). The aims for this study were to describe the neuropsychological course of CSE after first diagnosis and to detect prognostic factors for neuropsychological impairment after diagnosis., Methods: This prospective study follows a Dutch cohort of CSE patients who were first diagnosed between 2001 and 2011 and underwent a second neuropsychological assessment 1.5-2 years later. Cognitive subdomains were assessed and an overall cognitive impairment score was calculated. Paired t tests and multivariate linear regression analyses were performed to describe the neuropsychological course and to obtain prognostic factors for the neuropsychological functioning at follow-up., Results: There was a significant improvement on neuropsychological subdomains at follow-up, with effect sizes between small and medium (Cohen's d 0.27-0.54) and a significant overall improvement of neuropsychological impairment with a medium effect size (Cohen's d 0.56). Prognostic variables for more neuropsychological impairment at follow-up were a higher level of neuropsychological impairment at diagnosis and having a comorbid diagnosis of a psychiatric disorder at diagnosis., Conclusions: Results are in line with previous research on the course of CSE, stating that CSE is a non-progressive disease after cessation of exposure. However, during follow-up the percentage patients with permanent work disability pension increased from 14 to 37%. Preventive action is needed in countries where exposure to organic solvents is still high to prevent new cases of CSE.

Objectives: Large biobanks with uniform collection of biomaterials and associated clinical data are essential for translational research. The Netherlands has traditionally been well organized in multicenter clinical research on pancreatic diseases, including the nationwide multidisciplinary Dutch Pancreatic Cancer Group and Dutch Pancreatitis Study Group. To enable high-quality translational research on pancreatic and periampullary diseases, these groups established the Dutch Pancreas Biobank., Methods: The Dutch Pancreas Biobank is part of the Parelsnoer Institute and involves all 8 Dutch university medical centers and 5 nonacademic hospitals. Adult patients undergoing pancreatic surgery (all indications) are eligible for inclusion. Preoperative blood samples, tumor tissue from resected specimens, pancreatic cyst fluid, and follow-up blood samples are collected. Clinical parameters are collected in conjunction with the mandatory Dutch Pancreatic Cancer Audit., Results: Between January 2015 and May 2017, 488 patients were included in the first 5 participating centers: 4 university medical centers and 1 nonacademic hospital. Over 2500 samples were collected: 1308 preoperative blood samples, 864 tissue samples, and 366 follow-up blood samples., Conclusions: Prospective collection of biomaterials and associated clinical data has started in the Dutch Pancreas Biobank. Subsequent translational research will aim to improve treatment decisions based on disease characteristics.

The LifeLines Cohort Study is a large population-based cohort study and biobank that was established as a resource for research on complex interactions between environmental, phenotypic and genomic factors in the development of chronic diseases and healthy ageing. Between 2006 and 2013, inhabitants of the northern part of The Netherlands and their families were invited to participate, thereby contributing to a three-generation design. Participants visited one of the LifeLines research sites for a physical examination, including lung function, ECG and cognition tests, and completed extensive questionnaires. Baseline data were collected for 167 729 participants, aged from 6 months to 93 years. Follow-up visits are scheduled every 5 years, and in between participants receive follow-up questionnaires. Linkage is being established with medical registries and environmental data. LifeLines contains information on biochemistry, medical history, psychosocial characteristics, lifestyle and more. Genomic data are available including genome-wide genetic data of 15 638 participants. Fasting blood and 24-h urine samples are processed on the day of collection and stored at -80 °C in a fully automated storage facility. The aim of LifeLines is to be a resource for the national and international scientific community. Requests for data and biomaterials can be submitted to the LifeLines Research Office [LLscience@umcg.nl]., (© The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Although genome-wide association studies (GWAS) have identified many common variants associated with complex traits, low-frequency and rare variants have not been interrogated in a comprehensive manner. Imputation from dense reference panels, such as the 1000 Genomes Project (1000G), enables testing of ungenotyped variants for association. Here we present the results of imputation using a large, new population-specific panel: the Genome of The Netherlands (GoNL). We benchmarked the performance of the 1000G and GoNL reference sets by comparing imputation genotypes with 'true' genotypes typed on ImmunoChip in three European populations (Dutch, British, and Italian). GoNL showed significant improvement in the imputation quality for rare variants (MAF 0.05-0.5%) compared with 1000G. In Dutch samples, the mean observed Pearson correlation, r(2), increased from 0.61 to 0.71. We also saw improved imputation accuracy for other European populations (in the British samples, r(2) improved from 0.58 to 0.65, and in the Italians from 0.43 to 0.47). A combined reference set comprising 1000G and GoNL improved the imputation of rare variants even further. The Italian samples benefitted the most from this combined reference (the mean r(2) increased from 0.47 to 0.50). We conclude that the creation of a large population-specific reference is advantageous for imputing rare variants and that a combined reference panel across multiple populations yields the best imputation results.

Objective: To describe the enabling factors and barriers experienced in the Wheelchair Expert Evaluation Laboratory - implementation (WHEEL-i) project, in which scientific knowledge, tools and associated systematic analyses of hand-rim wheelchair propulsion technique, user's wheelchair propulsion capacity, wheelchair-user interface, and wheelchair mechanics were implemented in 2 rehabilitation centres., Design: Implementation project., Patients: Spinal cord injury., Methods: In this implementation project standardized tests were performed: wheelchair skills tests, 2 questionnaires, and a steady-state exercise test on a treadmill in which propulsion technique (forces and torques) and physical strain (oxygen uptake, heart rate and mechanical efficiency) were measured., Results: Good interpretation of the test outcomes was the most important barrier. In order to discuss individual wheelchair performance results with patients and clinicians, reference data were developed, smallest detectable differences were calculated and software was developed to simultaneously show video recordings and force and torque signals., Conclusion: Based on pilot results, the greatest barrier to systematic monitoring of the individual wheelchair fitting and learning process in rehabilitation with, among others, instrumented measurement wheels, was interpretation of outcomes. For proper interpretation of individual outcomes, the availability of reference data, smallest detectable differences and visualization of outcomes is of utmost importance.

Within the Netherlands a national network of biobanks has been established (Biobanking and Biomolecular Research Infrastructure-Netherlands (BBMRI-NL)) as a national node of the European BBMRI. One of the aims of BBMRI-NL is to enrich biobanks with different types of molecular and phenotype data. Here, we describe the Genome of the Netherlands (GoNL), one of the projects within BBMRI-NL. GoNL is a whole-genome-sequencing project in a representative sample consisting of 250 trio-families from all provinces in the Netherlands, which aims to characterize DNA sequence variation in the Dutch population. The parent-offspring trios include adult individuals ranging in age from 19 to 87 years (mean=53 years; SD=16 years) from birth cohorts 1910-1994. Sequencing was done on blood-derived DNA from uncultured cells and accomplished coverage was 14-15x. The family-based design represents a unique resource to assess the frequency of regional variants, accurately reconstruct haplotypes by family-based phasing, characterize short indels and complex structural variants, and establish the rate of de novo mutational events. GoNL will also serve as a reference panel for imputation in the available genome-wide association studies in Dutch and other cohorts to refine association signals and uncover population-specific variants. GoNL will create a catalog of human genetic variation in this sample that is uniquely characterized with respect to micro-geographic location and a wide range of phenotypes. The resource will be made available to the research and medical community to guide the interpretation of sequencing projects. The present paper summarizes the global characteristics of the project.

Objectives: Undergraduate medical teaching in occupational health (OH) is a challenge in universities around the world. Case-based e-learning with an attractive clinical context could improve the attitude of medical students towards OH. The study question is whether case-based e-learning for medical students is more effective in improving knowledge, satisfaction and a positive attitude towards OH than non-case-based textbook learning., Methods: Participants, 141 second year medical students, were randomised to either case-based e-learning or text-based learning. Outcome measures were knowledge, satisfaction and attitude towards OH, measured at baseline, directly after the intervention, after 1 week and at 3-month follow-up., Results: Of the 141 participants, 130 (92%) completed the questionnaires at short-term follow-up and 41 (29%) at 3-month follow-up. At short-term follow-up, intervention and control groups did not show a significant difference in knowledge nor satisfaction but attitude towards OH was significantly more negative in the intervention group (F=4.041, p=0.047). At 3-month follow-up, there were no significant differences between intervention and control groups for knowledge, satisfaction and attitude., Conclusions: We found a significant decrease in favourable attitude during the internship in the experimental group compared with the control group. There were no significant differences in knowledge or satisfaction between case-based e-learning and text-based learning. The attitude towards OH should be further investigated as an outcome of educational programmes.

Background: While many employees who have a chronic disease manage their jobs well, others are hampered in work performance, experience work-related problems and are at risk for job loss., Aims: To identify the practical and psychosocial barriers recognized by employees with chronic disease who experience work-related problems and to examine preferred work accommodations., Methods: A questionnaire was sent by mail and completed by current workers who have a chronic disease and experience serious problems at work., Results: One hundred and twenty-two employees participated in this study. On average, they had been ill for 10 years and 44% had more than one disease. The most outstanding work-related problems were psychosocial, including work-home interference and a lack of acceptance of the chronic disease. Performing and finishing work tasks and social relationships with supervisors or colleagues were also felt to be slightly problematic. The most preferred work accommodations included fewer work hours, working from home, a slower work pace and more autonomy in planning work tasks. Almost three-quarters of the respondents were so fatigued that they were at risk of sickness absence or work disability., Conclusions: A chronic physical disease may lead to both practical and psychosocial problems and serious fatigue. Managing psychosocial problems may decrease fatigue.

Background: Occupational diseases are generally underreported. The aim of this study was to evaluate whether a sentinel surveillance project comprising motivated and guided occupational physicians would provide higher quality information than a national registry for a policy to prevent occupational diseases., Methods: A group of 45 occupational physicians participated in a sentinel surveillance project for two years. All other occupational physicians (N = 1,729) in the national registry were the reference group. We compared the number of notifications per occupational physician, the proportion of incorrect notifications, and the overall reported incidence of occupational diseases., Results: The median number of notifications per occupational physician during the project was 13.0 (IQR, 4.5-31.5) in the sentinel group versus 1.0 (IQR, 0.0-5.0) in the reference group (P < 0.001). The proportion of incorrect notifications was 3.3% in the sentinel group and 8.9% in the reference group (P < 0.001). The overall reported occupational disease incidence was 7 times higher (RR = 6.9, 95% CI: 6.5-7.4) in the sentinel group (466 notifications per 100,000 employee years) than in the reference group (67 notifications per 100,000 employee years)., Conclusions: A sentinel surveillance group comprising motivated and guided occupational physicians reported a substantially higher occupational disease incidence and a lower proportion of incorrect notifications than a national registry., (Copyright 2008 Wiley-Liss, Inc.)

The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

Background: Occupational diseases are under reported. Targeted education of occupational physicians (OPs) may improve their rate of reporting occupational diseases., Aim: To study the effectiveness of an active multifaceted workshop aimed at improving OPs' reporting of occupational diseases., Methods: We undertook a comparative study with 112 OPs in the intervention group and 571 OPs as comparisons. The intervention was a 1-day workshop. Measurements of occupational disease reporting activity in both groups in 6-month periods before and after the intervention were collected via the national registration system. Measurements of OPs' knowledge, self-efficacy and satisfaction were made in the intervention group. Differences between the groups and predictive factors for reporting were subsequently analysed statistically., Results: The percentage of reporting OPs after the intervention was significantly higher in the intervention group compared to the comparison group at 19 versus 11% (P < 0.01). No differences were found in the average number of reported occupational diseases per reporting physician after the intervention: 3.7 (SD 5.37) versus 3.4 (SD 4.56) (not significant). The self-efficacy score was a predictive factor for reporting occupational diseases (P < 0.05). Measurements of knowledge and self-efficacy increased significantly (both parameters P < 0.001) and remained after half a year. Satisfaction was high (7.85 of 10)., Conclusions: An active, multifaceted workshop on occupational diseases is effective in increasing the number of physicians reporting occupational diseases. Self-efficacy measures are a predictive factor for such reporting.

Aim: To assess the need for quality improvement of diagnosing and reporting of noise-induced occupational hearing loss and occupational adjustment disorder., Methods: Performance indicators and criteria for the quality of diagnosing and reporting were developed. Self-assessment questionnaires were sent to all occupational physicians recorded on the Netherlands Centre for Occupational Diseases database. The performance of responding occupational physicians was then assessed by separate scores per performance indicator and by a total quality score., Results: Twenty-three questionnaires on noise-induced occupational hearing loss and 125 questionnaires on occupational adjustment disorder were available for analysis. The mean quality score for diagnosing and reporting was 6.0 (SD: 1.4) for noise-induced occupational hearing loss and 7.9 (SD: 1.5) for occupational adjustment disorder on a scale of 0-10. For noise-induced occupational hearing loss, there was a need for quality improvement of the aspects of medical history, audiometric measurement, clinical diagnosis of the disease and reporting. For occupational adjustment disorder, the assessment of other non-occupational causes needed improvement., Conclusions: The quality of diagnosing and reporting could be improved for noise-induced occupational hearing loss and occupational adjustment disorders. Information, education and practical tools are proposed for quality improvements.

Objective: This study attempted to determine the effectiveness of an intervention to enhance evidence-based advice given by occupational physicians., Methods: Altogether 106 occupational physicians were cluster randomized into 16 groups. The intervention group received a course in evidence-based medicine, followed by a 4-month period of case-method learning sessions in peer groups once every 2 weeks. During these sessions, the participants discussed their patients with respect to sickness absence and the existing evidence for return-to-work prognosis and effective interventions. The participants were assigned to perform a literature search at least once every 4 weeks. The primary outcome measure was the quality of advice based on the correct assessment of prognosis for return to work or the correct choice of return-to-work interventions. Secondary outcome measures were the quality of the searches performed by the intervention group, the use of evidence by all occupational physicians during the intervention period, and the potential predictors for advice quality., Results: Better return-to-work interventions were advised by the intervention group than by the control group after 2 months (88% versus 67%, P=0.01), but the difference had decreased after 4 months (76% versus 62%, not significant). No better assessments of prognosis were found for return to work. Most of the searches had a good quality (83% or 73%), and good searching was a positive predictor for a good choice of advised interventions (P=0.03). Without obligatory searches, no increase in evidence use was found., Conclusion: Evidence-based advice by occupational physicians in sickness absence episodes can be improved with multifaceted intervention. The actual search for evidence is an essential element.

Objectives: To evaluate the effectiveness and efficiency of a search strategy to find evidence-based answers to questions related to the possible occupational etiology of diseases., Methods: A controlled trial of 70 occupational health physicians and 55 insurance physicians who were asked to answer one out of four 'occupational disease case-vignettes' following the steps of evidence-based medicine (EBM). The intervention group were given the search strategy as a tool., Results: The intervention group scored significantly better than the control group in answering the main question of the case-vignette correctly (57% versus 37%) using more adequate search terms. The intervention group scored significantly better regarding satisfaction with the applied search strategy (28% very satisfied versus 8%). We found no differences in time spent in solving the case or in the intention of future practice of EBM., Conclusions: The introduction and application of specific search strategies can have a positive effect on the effectiveness of searching literature. Future initiatives for developing and testing specific search strategies in the field of occupational health should be encouraged.

Objectives: To study the occurrence and duration of sick leave as potential risk factors for permanent job loss after 24 months among 112 individuals with chronic arthritis and a disease related problem at work., Methods: Data collection was embedded in a multicentre randomised controlled trial in which the cost-effectiveness of a multidisciplinary job retention vocational rehabilitation programme for employees with chronic arthritis and a disease related problem at work was compared to usual outpatient care. Sick leave (complete or partial) was defined as absenteeism reported to the employer and permanent job loss as receiving a full work disability pension or unemployment. The association between sick leave at baseline and job loss after 24 months was investigated by multivariate logistic regression analysis, including those variables that were univariately significantly associated with job loss after 24 months., Results: At baseline, 60 of the 112 subjects (54%) were on sick leave, with a mean duration of 18.7 weeks, in half of these patients the sick leave was complete. After 24 months, 26 of the 112 patients (23%) had lost their job. The presence of complete sick leave (OR 4.74, 95% CI 1.86-12.07) and the depression score of the hospital anxiety and depression scale (OR 1.18, 95% CI 1.02-1.36) were significantly and independently associated with job loss after 2 years follow-up., Conclusion: The occurrence of complete sick leave was found to be an independent risk factor for job loss in patients with chronic arthritis who have a disease related problem at work.

The Western Scheldt Tunneling Project in the Netherlands provided a unique opportunity to evaluate the effects of trimix usage on the health of compressed air workers and the efficiency of the project. Data analysis addressed 318 exposures to compressed air at 3.9-4.4 bar gauge and 52 exposures to trimix (25% oxygen, 25% helium, and 50% nitrogen) at 4.6-4.8 bar gauge. Results revealed three incidents of decompression sickness all of which involved the use of compressed air. During exposure to compressed air, the effects of nitrogen narcosis were manifested in operational errors and increased fatigue among the workers. When using trimix, less effort was required for breathing, and mandatory decompression times for stays of a specific duration and maximum depth were considerably shorter. We conclude that it might be rational--for both medical and operational reasons--to use breathing gases with lower nitrogen fractions (e.g., trimix) for deep-caisson work at pressures exceeding 3 bar gauge, although definitive studies are needed.

Background: To enable occupational physicians (OPs) to make use of scientific information in the decision-making process, evidence-based occupational health practice is stimulated., Aims: To study the questions which arise in daily practice of OPs, and to evaluate the possible contribution of evidence-based medicine (EBM) strategies to answer these questions., Methods: Observation of 20 OPs during two consecutive half-day periods, followed by an interview to explore the topics that arose during the preceding period. The conscious or manifest and unconscious or latent questions by OPs were analysed, and the number of questions suitable for performing a search in scientific medical literature databases was assessed., Results: After 40 half-day periods, the OPs had asked 26 manifest questions and 348 latent questions; the latter were voiced during the interview. Of all the questions, 40% were clinical in nature and considered suitable for a literature search. The emphasis of these questions was on prognosis, susceptibility and diagnosis following individual consultations. A lack of time or 'no necessity to look for an answer' were the most important reasons for leaving the questions unanswered., Conclusions: OPs spontaneously formulated less than one question per working day. However, after an observation of their daily practice followed by an interview, many latent questions were formulated. A substantial number of these questions could be answered by EBM strategies. If OPs were encouraged more to improve the quality of their decision making, they might formulate more answerable questions and feel more inclined to search for answers.

On October 4, 1992 a cargo jet crashed in the Bijlmermeer district in Amsterdam, the Netherlands, killing 43 people and making hundreds homeless. Many years of confusion and prolonged media attention followed, including public debates and even a Parliamentary Inquiry as to the causes, exposure to various chemical, physical and biological risk factors, and related diseases. Two comprehensive large-scale medical investigations were carried out: a comparative epidemiological study analysing the long-term effects in involved and uninvolved care providers, and an individual medical examination of both residents and care providers with medical or psychological complaints. Later, an effects study was added analysing the effects of both medical investigations on the feelings of anxiety and the attribution of symptoms among the people involved. The epidemiological study revealed more physical and mental symptoms among the involved care providers. Blood, urine and saliva tests, however, revealed no differences. Although the studywas carried out with great care, the findings may have been biased to some extent by an evoked feeling of anxiety and by attention toward health problems brought about by the investigation itself. Another comment is the technical impossibility of stating, after so long a delay, that chemical exposure, e.g. to depleted uranium, could not have been a cause of adverse health effects. The effects study demonstrated that the medical investigations generally did not provide reassurance or decrease the anxiety about health problems. There was even a small increase in complaints. Residents with health problems that had been involved in the disaster still attribute their complaints to harmful chemical exposure.

Aims: To evaluate an occupational health intervention programme for workers at risk for early retirement., Methods: Between April 1997 and May 1998, 116 employees of a large company who were older than 50 years indicated that they would not be able to work up to their retirement. They were randomly assigned to an intervention (n = 61) or control group (n = 55). The intervention programme lasted six months and was executed by an occupational physician. Job position and number of sick leave days after two years were collected from the company's computer database. A questionnaire was sent to the employees at baseline, after six months, and after two years; it included the Work Ability Index, the Utrecht Burn Out Scale, and the Nottingham Health Profile measuring quality of life., Results: Fewer employees (11%) in the intervention group retired early than in the control group (28%). The total average number of sick leave days in two years was 82.3 for the intervention group and 107.8 for the control group. Six months after baseline, employees in the intervention group had better work ability, less burnout, and better quality of life than employees in the control group. Two years after randomisation no differences between the two groups were found., Conclusions: This occupational health intervention programme proved to be a promising intervention in the prevention of early retirement.

Aims: To study supervisory behaviour as a predictive factor for return to work of employees absent due to mental health problems; and to explore the association between conditional factors and supervisory behaviour., Methods: Eighty five supervisors of employees were interviewed by telephone. Questionnaires providing information on person related factors, depressive symptoms, and sickness absence were sent to the employees at baseline, three months, six months, and after one year. Three aspects of supervisory behaviour during the period of absence were measured: communication with the employee, promoting gradual return to work, and consulting of other professionals., Results: Better communication between supervisor and employee was associated with time to full return to work in non-depressed employees. For employees with a high level of depressive symptoms, this association could not be established. Consulting other professionals more often was associated with a longer duration of the sickness absence for both full and partial return to work. If sickness absence had financial consequences for the department, the supervisor was more likely to communicate frequently with the employee. Supervisors who were responsible for return to work in their organisation were more likely to communicate better and to consult more often with other professionals., Conclusion: Supervisors should communicate more frequently with employees during sickness absence as well as hold follow up meetings more often as this is associated with a faster return to work in those employees.

Objectives: This study assessed the extent and nature of information demands among occupational health physicians and their attitude towards the application of evidence-based medicine in occupational health., Methods: A questionnaire survey was carried out among a random sample of 159 physicians practicing occupational medicine in The Netherlands. The questionnaire investigated the type and number of questions encountered in daily practice, the actions taken in response, the physicians' experience in using scientific databases on the Internet, and their attitude towards evidence-based medicine., Results: The occupational health physicians' questions concerned medical, legal, and rehabilitation topics in particular. In pursuing answers to their questions, they generally chose to contact colleagues. Scientific databases were not consulted very often, although, in general, the attitude towards evidence-based medicine was positive. In addition to known barriers for practicing evidence-based medicine, occupational health physicians perceive a lack of scientific evidence in their field. The extensiveness of the field of knowledge in occupational health care was not regarded as an obstacle to their application of evidence-based medicine., Conclusions: Occupational health physicians have a demand for information on a broad range of topics, and, in most cases, their attitude towards evidence-based medicine is fairly positive. Besides education and training in evidence-based medicine, access to the Internet and the presence of a good knowledge infrastructure would help occupational health physicians use evidence-based medicine.

Aims: To examine the association between exposure to pushing/pulling at work and low back and shoulder complaints., Methods: A cross sectional questionnaire survey was carried out among 434 workers from several companies with mainly pushing/pulling tasks. From the same companies 188 workers without physically demanding tasks served as reference. The questionnaire was used to assess the exposure to pushing/pulling and other physical risk factors for low back and shoulder complaints. Mean scores at company level were used to classify groups into medium and high exposed to pushing/pulling and a reference group. Psychosocial factors at work were also assessed. Several pain related questionnaires were used to assess the 12 month prevalence of low back and shoulder complaints in three dimensions: trouble (ache, pain, discomfort), pain intensity, and disability. Prevalence rate ratios (PRs) were calculated using Cox's proportional hazards regression analysis., Results: The 12 month prevalence of low back complaints was almost equal for all three groups. The prevalence of shoulder complaints increased with an increase in exposure level. Adjusted PRs showed that the high exposed group had an increased risk for low back complaints compared to the reference group. For all dimensions of shoulder complaints a clear tendency towards a dose-response relation was observed. The high exposed group had significant PRs for shoulder complaints, ranging from 2.09 to 6.37. Generally, psychosocial factors had a confounding effect for pain intensity and disability, but not for trouble., Conclusions: For shoulder complaints a dose-response relation was observed for exposure to pushing/pulling. Low back complaints were less consistently associated with pushing/pulling. Stronger associations were observed for more severe cases of low back and shoulder complaints. It is hypothesised that work related psychosocial factors affect these associations.

An epidemiological study was carried out to explore the relationship between climatic factors and non-specific low-back and neck-shoulder symptoms in working populations. In a review of published literature, 27 studies were found which related climatic factors to musculoskeletal symptoms, but none of these studies specifically addressed the subject. It can be concluded that a relationship between climatic factors and musculoskeletal symptoms is considered at least plausible by both researchers, workers and patients, but that the epidemiological evidence appearing from literature is very weak. Questionnaire data which were collected on musculoskeletal symptoms, workload and perceptions of climatic conditions of 2030 workers in 24 different occupations were analysed multi-variately. About one-quarter of the workers related symptoms of the low back and neck-shoulders to climatic factors. They perceived climatic factors in most cases as aggravating factors for their symptoms. No seasonal influence on prevalence rates was reported. For low-back and neck-shoulder symptoms and for sick leave due to neck-shoulder symptoms, an association was found with climatic factors, and in particular with respect to draughts in relation to neck-shoulder symptoms. In addition, neck-shoulder symptoms were negatively related to frequent outdoor work. The findings suggest a relationship between climatic factors and musculoskeletal symptoms and call for further detailed investigations.

Objective: In this study the relationship has been studied between exposure time and potential prognostic factors and FEV1 percent predicted (FEV1-% pred) in workers with potroom asthma, after their transfer from exposure to exposure-free departments., Methods: Between 1970 and 1990 in a Dutch aluminium-production plant, 179 workers had been diagnosed as having potroom asthma. We carried out a follow-up study (n = 122) in the population still present at the factory 5 years after their relocation to an exposure-free department. In this study population, we examined the relationship between FEV1-% pred at follow-up, and exposure time: the time interval between start of exposure and diagnosis. To correct for confounding factors, we included age, pre-employment FEV1-% pred, allergy, medical treatment, and smoking in the analysis., Results: The mean FEV1-% pred at follow-up was within the normal range (90.3, SD 13.5). Long exposure time was significantly associated with a low FEV1-% pred at follow-up (P = 0.0046). Adjustment was necessary for pre-employment FEV1-% pred and current smoking as confounding factors., Conclusion: Long duration of exposure is a factor affecting FEV1 in workers with potroom asthma. The results of this study give support for additional preventive measures to be taken, such as early recognition of work-related respiratory complaints and repeated education.

In some respects, the Dutch seem to be forerunners in Europe. Occupational health care for all workers can be considered as a substantial progress. Nonetheless, The Netherlands has taken the lead in Europe regarding high work pressure, sickness absence and disability for work. The resulting focus on sickness absence management in many companies is associated with changes in the tasks and position of the occupational physician. Quality of occupational health care is not always as high as it should be, partly as a result of the commercial approach occupational health services have to adopt nowadays. However, the post-academic education programme, with special attention for training of skills, is increasingly adapted to occupational physicians working in a commercial environment. Moreover, a basis has been laid for a better infrastructure and occupational physicians show an increase in professional enthusiasm. Furthermore, co-operation between different professionals has become increasingly common, resulting in a more comprehensive support for companies. Efforts are being made for better co-operation with general practitioners and medical specialists. Finally, the priorities for future research have been clearly outlined by a programming study. Experts are in demand for studies regarding implementation and evaluation of interventions, especially cost-benefit analysis. Furthermore, work stress and musculoskeletal disorders remain on the research agenda.

Objectives: This study attempted to determine the prognostic indicators of low-back pain in an occupational health setting., Methods: The identification of prognostic factors of (i) functional disability after 3 months' follow-up, (ii) functional disability after 12 months' follow-up, and (iii) time to return to work among 120 workers who reported to an occupational health unit and were off work with low-back pain for at least 10 days. Crude and adjusted odds ratios and hazard ratios with 95% confidence intervals were estimated for the 3 outcome measures., Results: Factors related to a longer time to return to work were radiating pain, high functional disability at the beginning of the study, problems in relations with colleagues, and high work tempo and work quantity. High functional disability at the beginning of the study and a high avoidance coping style predicted functional disability at 3 months. Functional disability at 12 months was more accurately predicted by work-related and psychosocial factors., Conclusions: Especially radiating pain and functional disability predict a long duration of low-back pain in occupational health practice. Occupational physicians should also note work-related and psychosocial characteristics.

Objectives: To achieve a coherent programme of topics for research in occupational health and safety, with well founded priorities and to relate them to perceived gaps and needs in The Netherlands., Methods: In the first phase of the study 33 key informants were interviewed. In the second phase questionnaires were sent to 150 Dutch experts (including the key informants). Four groups were recruited, originating from: occupational health and safety services; scientific research institutes; governmental and other administrative bodies; and companies. Using the Delphi technique, the experts were asked to prioritize several topics, which were placed under different headings. In the third phase five workshops were organised to elaborate on the highly prioritized topics., Results: The response rates were 86% for the first and 81% for the second questionnaire. In the second round consistency was reached and consensus proved to be satisfactory; so that the Delphi process was stopped. There were surprisingly few differences in opinion between the four groups. The most important heading was "design/implementation/evaluation of measures", in which the topic cost-benefit analysis of measures had the highest score. "Assessment of relations between exposure and effect" was the second most important heading. Under this heading, topics on work stress were generally judged to be more important than topics on safety and biological, chemical, and physical hazards. The headings "occupational rehabilitation/sociomedical guidance" and "occupational health care/occupational health services" had about the sam priority, closely following the heading "assessment of relations between exposure and effect"., Conclusions: The general agreement on priorities should provide a sufficiently broad basis for decision makers to initiate a long term programme for occupational health research and development in The Netherlands.

Objectives: This cross-sectional study was performed in order to elucidate the relationship of musculoskeletal complaints with age, gender and physically demanding work in the Netherlands., Methods: Questionnaire data of male (n = 36756) and female (n = 7730) employees, gathered as part of periodical occupational health surveys among active workers in the Netherlands, were stratified for age, gender, and type of work demands. For each stratified group prevalence rates (PR) were calculated for complaints of the back, neck, upper and lower extremities. Moreover, prevalence rate differences (PRD) were estimated as an absolute effect measure of exposure to various types of physical work demands, with active employees in mentally demanding work acting as a reference population., Results: Musculoskeletal complaints among workers in physically demanding occupations were found to increase with age for both sexes. For several complaints, substantially higher rates were reported for women than for men, with a relatively high number of complaints observed among the older female workers (around 40% for complaints of back, upper and lower extremities). Significant PRDs were present in particular for employees in heavy physically demanding occupations and in jobs with mixed mental and physical work demands., Conclusions: With the ageing of the workforce in mind, these findings stress the need for implementation of preventive measures. Special attention towards the susceptible group of female employees, the elderly age groups in particular, seems justified. In order to clarify the combined effects of age and physical work demands on musculoskeletal complaints, additional studies are required.

Objectives: The main objective is to describe the potential health and work problems of the aging employees in the Dutch working population. In this way, we can identify groups at extra risk of specific health problems., Methods: In The Netherlands, occupational health services gather questionnaire data about work and health as part of periodical occupational health surveys (POHSs). These data from the POHSs of complaints about health and working conditions, aggregated into occupational groups and age categories, are used to provide indications for groups at extra risk of specific health problems. These problems are assessed by overviews of the relation between age and complaints about health and working conditions., Results: Almost all of the health questions show an increase in health complaints with increasing age. White collar workers, especially the high grade white collar workers, usually have lower complaint percentages on health questions than blue collar workers. Female employees have relatively high complaint percentages on the health questions. Differences between occupational groups in the complaints about work and working conditions reflect the differences in work demands and exposure. The relation between age and work complaints is generally inconsistent and weak. The complaint percentages on work questions of female employees tend to be equal to or lower than those of the male employees., Conclusions: The absence of a clear increase of work complaints with advancing age in the presence of a decrease in health and working capacity may be explained by a selective turnover in the working population, especially in demanding occupations. To enhance the work participation of older employees it may be necessary to reduce the work demands and to increase decision latitude.

Due to political priorities and benefit arrangements, prevention of work incapacity has played a minor role in employers' policies in the Netherlands. However, the comparatively high sickness absence rates and large numbers of disability benefit recipients in the Netherlands have fostered preventive policies and measures regarding unfavourable working conditions. Corresponding to recent changes in legislation, the role of occupational health and safety services will substantially increase in the coming years. Part of the new orientation will be a multi-disciplinary staff structure and more attention to tailor-made services and effectiveness. There is much debate about the precise role for occupational physicians in the control of sickness absenteeism in companies. This paper presents several instruments which are now being applied or which are still in a developmental stage. The issues of prevention of sickness absence and monitoring of long-term sick employees will remain a substantial part of the responsibilities of occupational health and safety services.

Internationally, the debate on aims for occupational health policy is expanding its horizons. Included among the issues are not only concerns about safety for workers, but also for their progeny. Equality among the sexes is also assuming a prominent position. In several countries, existing and proposed legislation already considers these matters. In the course of this article it is argued that this legislation and its implementation are inadequate. There are several reasons for this. Firstly, what constitutes health risks for workers exposed to chemical substances is subject to different interpretations. This is further complicated when one includes risks to reproductive function and to the progeny: the reproductive risks of toxicity. The different interpretations of the concepts of safety and equality are also discussed. There are differences in regulations and in standards about whether or not safety factors should be used when knowledge is uncertain. The operation of reasonable measures with a generic or sex specific policy also differs. Secondly, the current occupational exposure limits are set too high. These aspects are considered and it is probable that the policy aims should be made more specific. An elaborated approach that includes the "precautionary principle" in safety standards is proposed. To advise employers in their role as managers of reproductive risks of toxicity, a recently developed system for occupational health and safety services is described. This system is based on two criteria: effectiveness and reasonableness of proposed measures. The effectiveness criterion includes the precautionary principle; the reasonableness criterion includes equal rights and opportunities for men and women. Finally, a supportive governmental policy that is consistent with the most recent international development is recommended.

In this article, we describe methods which have been applied in the compilation of the Atlas of Health and Working conditions by Occupation. First, we discuss the need for information systems to identify problems concerning working conditions and health. Such information systems have an exploratory purpose, being deployed to identify work risks in companies, groups of occupations and sectors of industry, and can also be a starting point for the generation of hypotheses on the causes of adverse health effects. In the Netherlands, occupational health services gather questionnaire data about work and health as part of periodical occupational health surveys. In the atlas, aggregated questionnaire data for 129 occupations with male employees and 19 occupations with female employees are presented. In this article, we explain the methodology used to compare occupations with regard to each item in the questionnaire. We then discuss applications of these occupational ranking lists. The cross-sectional nature of the data collection, various forms of selection and the limited size of some occupational populations have to be taken into account when interpreting the results. Occupational ranking lists can be applied in the allocation of resources and in the design of scientific research. The overviews for each occupation, presented in the second half of the atlas, provide an occupational profile of existing problems with respect to work and health. These profiles are used as basic information to develop a practical policy on working conditions and health.

Among personnel of the city of Amsterdam the incidence of disability as a result of musculoskeletal problems amounts to 15 per 1000 person-years in the refuse collecting department. A disability prevention programme in accordance with literature was started to decrease this high incidence of disability. In the process-evaluation after 2 years from the start of the project it turned out that only three of the ten preventive measures advocated were realized. These meagre results were explained by strategic factors such as lack of motivation among management and the fact that policy on worker health protection was isolated from the overall company policy. Recommendations for future evaluation research are given.

The outline of a study in occupational health services (OHS) on the prevention and control of effects of whole-body vibration is described and preliminary results are presented here. The study comprises an inventory of current activities of occupational health services in vibration-related issues, the development of a specific OHS-programme and evaluation of this programme, mainly on process level. Results of the inventory, a questionnaire survey in occupational health services (n = 112, response 67%), show that the impact of OHS in prevention and control of adverse health effects is small. The development and evaluation of a specific OHS-programme may be useful in setting up a preventive approach. Some methodologic problems are discussed also.

Several hundreds of thousands of preemployment medical examinations are performed in The Netherlands each year, with the objective of screening for obvious risks for the applicants or others. Neither the efficacy of these examinations nor determinants for rejection are known. Altogether 101,754 preemployment medical examinations of applicants for governmental functions were analyzed. For one-fifth of the applicants some medical diagnosis was recorded. The overall rejection percentage was 0.6%, being highest for job categories involving public safety and high physical demands, but never exceeding 4%. Age was positively correlated with rejection percentage. Except for the diagnostic category "disorders of the musculoskeletal system" no relation between diagnostic category and job demands was apparent. Medical diagnoses frequently encountered among rejected applicants were also common among successful applicants. If selection aiming at reducing absenteeism or work disablement is considered to be the only goal of preemployment medical examinations, then their efficacy appears to be low for many job categories.

Non-auditory effects of noise were studied among 539 male workers from seven industries. The LAeq, assessed by personal noise dosimetry, has been used to study acute effects. Various indices of total noise exposure, involving level and duration, were developed for long-term effect studies. In the analysis close attention was paid to prevent confounding, e.g. by other adverse working conditions. As expected, hearing loss increased with total noise exposure. Tinnitus was related particularly to hearing loss. Dizziness and hoarseness, however, were not related with noise exposure in this study. Also no correlation could be demonstrated between blood pressure and total noise exposure after correction for age, relative weight and various confounding variables. Use of hearing protection, selection processes and incomplete analysis of interactions between independent variables are suggested for possible explanation. About two-thirds of the workers reported noise annoyance. Various aspects were mentioned, such as irritation, surprise and impairment of communication and perception. Mentally stressful tasks appeared to be the most noise-sensitive. Particularly annoying noise sources, mental work load and time pressure had a relatively large impact on noise annoyance in comparison with the influence of noise level (LAeq) itself. Stress responses were not simply related to the noise exposure level, although consistent positive relations could be demonstrated between symptoms of stress and noise annoyance. Various findings led to the conclusion that noise exposure together with stressful mental activities may lead to disturbed concentration, irritation and annoyance. Experienced stress in turn may render workers more susceptible to noise. To overcome some limitations of this study, cohort studies and studies designed to assess interaction-effects are recommended.