Growth of Headache Research: A 1983-2014 bibliometric study.

Aim This study charts the growth of the scientific journal literature on headache for 30+ years (1983-2014). Methods Using the Web of Science, articles published in four two-year periods (1983-1984, 1993-1994, 2003-2004, 2013-2014) from journals indexed in the Science Citation Index Expanded database were retrieved and analyzed. Results From 1983-1984 to 2013-2014, the scientific literature on headache increased nearly fourfold (3.8) from 468 to 1776 articles; the number of participating countries more than doubled (26 to 67); and the two most prolific countries in each period were the USA and Italy. While several European countries (Italy, Germany, UK and Denmark) were among the top 10 in each period, the notable appearance of Turkey, China and Brazil among the top 10 in 2013-2014 indicates the growing geographic spread of publications on headache research. Meanwhile, the comet-like distribution of journals has not changed: two journals, Headache and Cephalalgia, persist throughout as the nucleus, with the tail increasing more than threefold from 141 journals in 1983-1984 to 462 in 2013-2014. Conclusion Our study follows the recent growth and spread of the scientific literature on headache research and should stimulate further bibliometric investigation in this field.