A Study of Grey Literature in the Field of Nutrition, Health and Food Safety Quantity, Retrievability and Scientist’s Point of View

Aims: Grey literature covers all reports from public research institutes, which are not peer-reviewed scientific papers. The aim of this article is to explore the amount and extent of grey literature in the field of nutrition, health and food safety, the retrievability and the view of several scientists on this matter.
Study Design: An explorative descriptive, semi-quantitative study.
Methodology: During a three week survey in June 2013, a questionnaire was sent to 97 scientists in the field of nutrition, health and food safety, of which 44 were returned. Most of the scientists were working in European governmental, academic or research institutes. Questions included an estimation of the quantity and retrievability of the grey literature at that institute, as well as questions about better ways to make grey literature more accessible. To compare the current needs for grey literature and its accessibility with future needs, a questionnaire was also designed and distributed via email and social media among students in the Netherlands; in total 134 replies were received of which 96 were included in the analysis. Outcomes of the research were compared with literature.
Results: Scientists were aware of the existence of grey literature, but had mostly no idea about the amount and extent of it within their own institutes, which was an important drawback in this study. Also, the reported number by scientists did not match the number found on websites of the institutes, which may be due to language barriers, costs and the use of passwords. Although there are various repositories especially for the storage of grey literature, most scientists are not aware of them. The results also gave some insight in the perceived needs and problems with retrievability.
Conclusion: This study should be considered as a first attempt to explore the grey literature in the field of nutrition, health and food safety. The main finding was that the quantity and impact of grey literature is not to be underestimated. Scientists indicated that they want to improve retrievability of the documentation since they are considered often very valuable to the scientific community and the general public. Increasing the awareness of the amount grey literature and ways to improve the accessibility are points of attention for further research.