Psychiatry and the Hirsch h-index: The Relationship Between Journal Impact Factors and Accrued Citations

There is considerable debate on the use and abuse of journal impact factors and on selecting the most appropriate indicator to assess research outcome for an individual or group of scientists. Internet searches using Web of Science and Scopus were conducted to retrieve citation data for an individual in order to calculate nine variants of Hirsch's h-index. Citations to articles published in a wide range of psychiatric journals in the periods 1995-99 and 2000-05 were analyzed using Web of Science. Comparisons were made between journal impact factor, h-index of citations from publication to 2008, and the proportion of articles cited at least 30 or 50 times. For up to 14 years post-publication, there was a strong positive relationship between journal impact factor and h-index for citations received. Journal impact factor was also compared to the percentage of articles cited at least 30 or 50 times-a comparison that showed wide variations between journals with similar impact factors. This study found that 40%-50% of the articles published in the top ten psychiatry journals ranked by impact factor acquire 30 to 50 citations within ten to fifteen years. Despite certain flaws and weaknesses, the h-index provides a better way to assess long-term performance of articles or authors than using a journal's impact factor, and it provides an alternative way to assess a journal's long-term ranking.