I. T. J. Braam

Evaluation research in occupational health services: general principles and a systematic review of empirical studies.

OBJECTIVES: To study the nature and extent of evaluation research in occupational health services (OHSs). METHODS: Literature review of evaluation research in OHSs. On the basis of a conceptual model of OHS evaluation, empirical studies are categorised into aspects of input, process, output, outcome, and OHS core activities. RESULTS: Many methods to evaluate OHSs or OHS activities exist, depending on the objective and object of evaluation. The amount of empirical studies on evaluation of OHSs or OHS activities that met the non-restrictive inclusion criteria, was remarkably limited. Most of the 52 studies were more descriptive than evaluative. The methodological quality of most studies was not high. A differentiated picture of the evidence of effectiveness of OHSs arises. Occupational health consultations and occupational rehabilitation are hardly studied despite much time spent on the consultation by occupational physicians in most countries. The lack of effectiveness and efficiency of the pre-employment examination should lead to its abandonment as a means of selection of personnel by OHSs. Periodic health monitoring or surveillance, and education on occupational health hazards can be carried out with reasonable process quality. Identification and evaluation of occupational health hazards by a workplace survey can be done with a high output quality, which, however, does not guarantee a favourable outcome. CONCLUSIONS: Although rigorous study designs are not always applicable or feasible in daily practice, much more effort should be directed at the scientific evaluation of OHSs and OHS instruments. To develop evidence-based occupational health care the quality of evaluation studies should be improved. In particular, process and outcome of consultation and rehabilitation activities of occupational physicians need to be studied more.

Validity of a diary estimating exposure to tasks, activities, and postures of the trunk

The validity of a diary that estimates exposure to tasks, activities, and postures of the trunk was determined by comparing these self-reported exposure data with observational data of a whole working day. Two populations were studied: 32 professional drivers and five nurses. The nurses and 16 drivers also filled out a shortened version of the diary during another working day. Both versions of the diary showed poor agreement with observations over the same period. However, for variables concerning activities and postures of the trunk agreement was improved by the shortening of the diary. It is concluded that in epidemiologic studies observational measurements of exposure cannot validly be replaced by diaries or similar self-reported exposure data, because the self-reports easily lead to misclassification.

Evaluation of an occupational health intervention programme on whole‐body vibration in forklift truck drivers: a controlled trial

Objectives: To evaluate process and outcome of a multifaceted occupational health intervention programme on whole-body vibration (WBV) in forklift truck drivers. Methods: An experimental pretest/post-test control group study design. The authors trained occupational health services (OHS) in the experimental group in the use of the programme. OHS in the control group were asked to deliver care as usual. In total, 15 OHS, 32 OHS professionals, 26 companies, and 260 forklift drivers were involved. Post-test measurements were carried out one year after the start of the programme. Results: Baseline data before the start of the programme showed no difference between experimental and control group. Results of the outcome evaluation indicate a slight, although not statistically significant, reduction of WBV exposure in the experimental group (p = 0.06). Process evaluation revealed a positive influence on company policy toward WBV, attitude and intended behaviour of forklift drivers, and a trend towards an increase in knowledge of OHS professionals and company managers. The number of observed control measures with a major impact (levelling of surface and reduction of speed) was rather low. In those cases where control measures had been taken, there was a significant reduction in WBV exposure. This limited effect of the programme might be caused by the short period of follow up and the dropout of participants. The feasibility and the usefulness of the programme within the OHS setting were rated good by the participants. Conclusions: This programme to decrease WBV exposure was partially effective. Significant effects on intermediate objectives were observed. More research on the effectiveness of intervention in the field of WBV is needed.

Sentinel Surveillance of Occupational Diseases: A Quality Improvement Project

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.

Time trends and blind spots: what employers, employees and policy-makers want to know about occupational diseases

Abstract Occupational illnesses and accidents impose a heavy burden on both workers and employers and represent enormous economic costs. This burden could be substantially reduced through preventive measures. This paper reports on a Dutch survey to investigate what information employers, employees, policy-makers and other stakeholders need to prevent occupational diseases and how these information needs can best be met. Our survey consisted of two rounds of interviews. In the first round, we interviewed 11 key stakeholders from employers organisations, employees organisations, the Dutch government and labour inspectorate, the EU authorities and the Dutch Society of Occupational Physicians. In the second, we asked 14 disease registration experts to comment on the results of the first round and to give their opinion on what they thought was the best way of meeting stakeholders information needs. Between them, the experts represented six European countries. From the first round of interviews, we deduced five categories of information that stakeholders need: time trends of occupational diseases for setting policy priorities cases of new occupational diseases for early preventive action disease patterns in specific occupational groups for focused prevention measures consequences of occupational diseases and resulting measures for policy evaluation purposes blind spots to reveal areas where more investigation is needed. The interviews with experts revealed that it is wise to rely on several instruments and findings to meet the comprehensive information needs of stakeholders, such as sentinel surveillance, epidemiological studies and case tracing. In addition, the experts indicated that linking registration to prevention requires closer communication between providers of occupational disease statistics and stakeholders.

Welke bedrijfsarts meldt beroepsziekten

SamenvattingEen prospectief cohortonderzoek is uitgevoerd onder 138 PIM-bedrijfsartsen gedurende 3 jaar om voorspellers van het aantal beroepsziektemeldingen te bepalen. Als mogelijk voorspellend zijn factoren van het gedragsmodel ASE onderzocht: attitude, sociale invloeden, zelfvertrouwen, kennis, ervaring en ervaren barrières. De analyses zijn verricht met behulp van lineaire en multivariate regressieanalyse. Het aantal beroepsziektemeldingen over 3 jaar was 3914 met een gemiddelde van 28 (SD 34,3) en een mediaan van 17. De somscores voor zelfvertrouwen (p=0,019), kennis (p=0,114), gebruik van de helpdesk (p=0,079) en barrières (p=0,055) correleerden met de uitkomst en verklaarden samen 7% van de meldingen. Op vraagniveau kwamen zelfvertrouwen bij het melden (p=0,003) en (gebrek aan) tijd voor melden (p=0,003) het sterkst naar voren. Het NCvB faciliteert PIM-deelnemers op zelfvertrouwen en efficiëntie door de jaarlijkse workshop en het efficiënter maken van het meldingsproces. De bedrijfsarts en de arbodienst kunnen meer prioriteit geven aan het melden en aan preventie van beroepsziekten.SummaryWhich occupational physician reports occupational diseases? A 3-year prognostic study among participants of the Sentinel Surveillance System for Occupational Disease Notification (PIM)Reporting occupational diseases is a core task for occupational physicians. Though they are legally obliged to report occupational diseases, this is not always done, which results in underreporting. A 3-year prospective cohort study was performed among 138 occupational physicians contributing to the Sentinel Surveillance System, in order to identify alterable determinants of the number of occupational disease reports. Potential determinant factors from the behavioural ASE model were examined: attitude, social influence, self-efficacy, knowledge, experience and perceived barriers. The analyses were performed with linear and multivariate regression analysis. The number of reported occupational diseases over 3 years was 3914, with an average of 28 (SD 34.3) and a median of 17. The sum scores for self-confidence (p=0.019), knowledge (p=0.114), helpdesk use (p=0.079) and perceived barriers (p=0.055) correlated with the result and together these explained 7% of the reports. At question level self-efficacy in the reporting process (p=0.003) and (lack of) the time needed for reporting (p=0.003) came strongest to the fore. The explained variance is low. There are more factors influencing the reporting of occupational diseases, which apparently did not become clear in this study. The NCvB stimulates the self-efficacy and efficiency of the participants of the sentinel surveillance system with an annual workshop and an increased efficiency of the registration process. The occupational physicians and the occupational health services could give the reporting and prevention of occupational diseases a higher priority.