Abstract: We included seven RCTs and five CBA studies. Six studies evaluated the effectiveness of educational materials alone, one study evaluated educational meetings, four studies evaluated a combination of the two, and one study evaluated a multifaceted educational campaign for increasing the reporting of occupational diseases by physicians. We judged all the included studies to have a high risk of bias. We did not find any studies evaluating the effectiveness of Internet-based interventions or interventions on procedures or techniques of reporting, or the use of financial incentives. Moreover, we did not find any studies evaluating large-scale interventions like the introduction of new laws, existing or new specific disease registries, newly established occupational health services, or surveillance systems. Educational materials We found moderate-quality evidence that the use of educational materials did not considerably increase the number of physicians reporting occupational diseases compared to no intervention (risk ratio of 1.11, 95% confidence interval (CI) 0.74 to 1.67). We also found moderate-quality evidence showing that sending a reminder message of a legal obligation to report increased the number of physicians reporting occupational diseases (risk ratio of 1.32, 95% CI 1.05 to 1.66) when compared to a reminder message about the benefits of reporting. We found low-quality evidence that the use of educational materials did not considerably increase the rate of reporting when compared to no intervention. Educational materials plus meetings We found moderate-quality evidence that the use of educational materials combined with meetings did not considerably increase the number of physicians reporting when compared to no intervention (risk ratio of 1.22, 95% CI 0.83 to 1.81). We found low-quality evidence that educational materials plus meetings did not considerably increase the rate of reporting when compared to no intervention (rate ratio of 0.77, 95% CI 0.42 to 1.41). Educational meetings We found very low-quality evidence showing that educational meetings increased the number of physicians reporting occupational diseases (risk ratio at baseline: 0.82, 95% CI 0.47 to 1.41 and at follow-up: 1.74, 95% CI 1.11 to 2.74) when compared to no intervention. We found very low-quality evidence that educational meetings did not considerably increase the rate of reporting occupational diseases when compared to no intervention (rate ratio at baseline: 1.57, 95% CI 1.22 to 2.02 and at follow-up: 1.92, 95% CI 1.48 to 2.47). Educational campaign We found very low-quality evidence showing that the use of an educational campaign increased the number of physicians reporting occupational diseases when compared to no intervention (risk ratio at baseline: 0.53, 95% CI 0.19 to 1.50 and at follow-up: 11.59, 95% CI 5.97 to 22.49). We found 12 studies to include in this review. They provide evidence ranging from very low to moderate quality showing that educational materials, educational meetings, or a combination of the two do not considerably increase the reporting of occupational diseases. The use of a reminder message on the legal obligation to report might provide some positive results. We need high-quality RCTs to corroborate these findings. Future studies should investigate the effects of large-scale interventions like legislation, existing or new disease-specific registries, newly established occupational health services, or surveillance systems. When randomisation or the identification of a control group is impractical, these large-scale interventions should be evaluated using an interrupted time-series design. We also need studies assessing online reporting and interventions aimed at simplifying procedures or techniques of reporting and the use of financial incentives.

Plain-language summary: We included 12 studies. Six studies evaluated the effectiveness of educational materials alone; one study evaluated the effectiveness of educational meetings; and four studies evaluated a combination of the two in increasing the reporting of occupational diseases by physicians. A further study evaluated the effectiveness of a complex educational campaign acting at society level. We searched for studies until January 2015. We found that the use of educational materials did not considerably increase the number of physicians reporting occupational diseases, but a legal obligation reminder message did. Furthermore, we found that the use of educational materials did not considerably increase the rate of reporting occupational diseases. Similarly, we found that the use of both educational materials and meetings did not considerably increase the number of physicians reporting occupational diseases or the rate of reporting. The same holds for the use of educational meetings alone. The use of an educational campaign appeared to increase the number of physicians reporting occupational diseases, although this was based on very low-quality evidence. We need high-quality studies to clarify the effectiveness of these interventions. This review was unable to determine the effectiveness of interventions other than education like the use of financial incentives, which could be an important form of motivation in changing physicians' behaviour. Such small-scale interventions could be investigated using larger randomised controlled trials, while the evaluation of large-scale interventions like legislation should use an interrupted time-series design.