period of 1952–2014

Sa’ed H. Zyoud1,2 Background: Publication of scientific articles related to khat (Catha edulis) in peer-reviewed journals is considered a measure of research productivity. The principal objectives of this study were to quantify the research contribution related to khat at the global level, as well as to determine its relative growth rate, collaborative measures taken, productivity at the institutional level, and the most prolific journals publishing on the topic. Methods: On the basis of title words related to khat, publications were identified for all data in Scopus bibliographic database’s history up to December 31, 2014. The research productivity for the top 10 countries was evaluated in relation to the population size and gross domestic product (GDP) in 2013. Results: The criteria were met by 651documents published in 51 countries. The largest number of articles associate