Evolution of the Scientific Literature on Pain from 1976 to 2007

Objective.  This study traces the evolution of the scientific literature on pain published during the last 30+ years (1976–2007). Methods.  Using the Web of Science®, pain-focused journal articles from the Science Citation Index Expanded™ published in 1977, 1987, 1997, and 2007 were retrieved and analyzed. Results.  The number of pain-related publications rose from 1,562 articles for 1976–77 to 9,159 PubMed for 2006–2007, with slow growth for the period 1976–1995, and rapid increases from 1995–2007. The analysis of contributing countries showed two major players, the United States and the UK; the doubling of the number of countries involved in pain research from 40 in 1977 to 82 in 2007; and the appearance in 2007 of The Netherlands, Turkey, China, and Brazil among the top-15 most prolific contributors. During the 30-year period, the number of journals publishing pain-related research increased nearly 2.5-fold (363 journals in 1977 vs 972 in 2007), including 14 new, international pain-focused journals since 2000. Additionally, while there were only two pain journals (Pain and Headache) in 1977, 15 pain-focused journals were indexed in 2007 with the result that 17 of the top-20 pain-focused journals in 2007 did not exist in 1977. Conclusion.  The rapid evolution and explosion of pain research in the last 30+ years was reflected in substantial changes in the landscape of the contributing countries and in the scientific journals targeted by pain researchers.