Worldwide research productivity in the field of back pain A bibliometric analysis

Background: This study aimed to show the world research productivity in the field of back pain and to help researchers follow the scientific development and promote the cooperation in this field. Methods: Web of Science (WoS) database was searched from 1995 to 2016 without other restrictions. The keywords were as follows: "lumbar NEAR pain," "back pain," "dorsalgia," "backache," "lumbago," "back NEAR disorder," and "discitis." The following information of retrieved articles was analyzed: countries/territories, journals, publication year, authors, citation reports, and institutions. Publication activity was further adjusted for countries by gross domestic product (GDP) and population size. Results: A total of 50,970 articles were retrieved in WoS database from 1995 to 2016. The United States published the biggest number of articles (16,818, 33.00%), followed by England (4,582, 8.99%), Germany (3,871, 7.60%), Canada (3,613, 7.09%), and Australia (3,063, 6.01%). Sweden ranked the first after adjusted for publication, and Netherlands ranked the first after adjusted for GDP. Besides, there was positive correlation between total number of publications and GDP for each country (P <. 05). Harvard University was the most productive institution (917, 1.80%), Maher CG was the most productive author (229, 0.45%) and Spine was the most popular journal (3605, 7.07%) in the field of back pain research. Moreover, the article titled "Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale" in Pain had the highest citations (1749). Conclusion: There was a significant increase in annual publications concerning back pain research worldwide. The total number of publications was positively associated with GDP in main productive countries. The United States was the most productive country, Harvard University was the most productive institution, Maher CG was the most productive author and Spine was the most popular journal in the field of back pain.