Bibliometric indicators in Occupational Safety and Health field

Introduction
Bibliometric indicators are the result of statistical and mathematical techniques used in bibliometrics to measure the quantity and impact of scientific publications. One of the most known indicators is the Impact Factor (IF), a measure of the frequency with which the "average article" in a journal has been cited in a particular year. It is a ratio between citations and recent citable items published.

Methods
Numerous criticisms have been made on the use of IF, among the others the fact that it may be incorrectly applied to determine “author impact” rather than to compare journals. In recent years, other freely available bibliometric indicators have been proposed as an alternative to traditional IF, such as h-index proposed in 2005 by J.E. Hirsch.

Results
According to this indicator, a researcher with an index of h means that he has published h papers each of which has been cited by others at least h times. Thus, the h-index reflects both the number of publications and the number of citations per publication. This index can also be applied to the productivity and impact of a group of scientists, such as a department, university or country. The scientific community has shown a huge interest for this indicator, whose the main advantage is to combine a measure of quantity (publications) and impact (citations) in a single indicator.

Discussion
The most important data sources for bibliometric analysis are the database of the Institute for Scientific Information (ISI), which include Web of Science (WoS) and Journal of Citation Reports (JCR); Scopus of Elsevier; and Google Scholar. The aim of this paper is to analyse the relationship of the h-index with other bibliometric indicators (IF, number of citations, number of citations/document) in the Occupational Safety and Health field in order to evaluate effectiveness and trend of the scientific communication in the field.