SNIP measures contextual citation impact by weighting citations based on the total number of citations in a subject field.
SJR is a prestige metric based on the idea that not all citations are the same. SJR uses a similar algorithm as the Google page rank; it provides a quantitative and a qualitative measure of the journal’s impact.
The Impact Factor measures the average number of citations received in a particular year by papers published in the journal during the two preceding years.
© Thomson Reuters Journal Citation Reports 2015
To calculate the five year Impact Factor, citations are counted in 2014 to the previous five years and divided by the source items published in the previous five years.
© Journal Citation Reports 2015, Published by Thomson Reuters
Annals of Emergency Medicine, the official journal of the American College of Emergency Physicians, is an international, peer-reviewed journal dedicated to improving the quality of care by publishing the highest quality science for emergency medicine and related medical specialties. Annals publishes original research, clinical reports, opinion, and educational information related to the practice, teaching, and research of emergency medicine. In addition to general emergency medicine topics, Annals regularly publishes articles on out-of-hospital emergency medical services, pediatric emergency medicine, injury and disease prevention, health policy and ethics, disaster management, toxicology, and related topics. The journal welcomes submissions from international contributors and researchers of all specialties.
Although Annals of Emergency Medicine is the official journal of the American College of Emergency Physicians (ACEP), the journal maintains editorial independence from ACEP. Its content is selected by the editorial board and does not necessarily reflect the policies and beliefs of ACEP.
Annals continues to be the largest circulation peer review journal in emergency medicine (over 33,000 subscribers, several times its nearest competitor). It is also one of the most accessible to non-subscribing readers, since more than 8,000 institutions include Annals in their online licenses for ScienceDirect (the world's largest electronic collection of science, technology and medicine full text and bibliographic information). ScienceDirect was utilized for access to Annals articles approximately 940,000 times in 2015. Annals is also available on the Web (with full text of all articles dating back to its inception), where it received more than 1,477,000 page views in 2015.
Annals is the emergency medicine journal most frequently cited by authors and has the highest impact factor over the years of all 25 journals in the emergency medicine category of the SCI (Science Citation Index). The impact factor (the average number of citations per published article) is the commonest measure of journal influence; the 2015 impact factor for Annals was 5.008. Not only is Annals most frequently cited, but it is cited more promptly and longer than any other emergency medicine journal (9.6 years, versus only 5.1 years for its nearest competitor).
Annals' articles generate considerable interest in the lay media. During the calendar year 2015, there were 4,522 hits in various media outlets, including print, television, radio blogs and social media. Major outlets included Associated Press, CNBC, Forbes Magazine HealthDay, the Huffington Post, Physician's Weekly, the Philadelphia Inquirer, Politico, Reuters Health, US News and World Report, and the Washington Post.
Annals is an international journal; more than half of the full text articles accessed via ScienceDirect were downloaded by readers in countries outside the U.S. Our contributors are also international in scope; in 2015 submissions came to us from 65 different countries, with 46% of submissions originating outside the United States, and 24% originating outside North America and Western Europe. The largest volume other than the U.S. was submitted from Canada, Taiwan, France, United Arab Emirates, Australia, Italy, Iran, China and the Netherlands, in descending order. But the list also includes Bosnia, Cyprus, Djibouti, Jordan, Lebanon, Qatar, and Vietnam.
We strongly believe we have an obligation to make our journal available to international audiences regardless of their financial resources, and therefore have participated for many years in the HINARI initiative sponsored by large journal publishers (http://www.who.int/hinari/en), which makes Annals available free or at greatly reduced cost in low-income countries.