Musculoskeletal diseases, with circumstances such as osteoarthritis, rheumatoid arthritis, and fibromyalgia, are among the prominent causes of pain and disability worldwide, with an estimated global prevalence of 810 million in 2010. In 2005, it was estimated that nearly 27 million US adults have clinical osteoarthritis (OA), a number which is likely to increase significantly in the next 20 years as the amount of adults over 65 years of age rises. Arthritis and other rheumatic conditions signify the most common cause of disability in the US. Most of these rheumatic conditions do not have effective disease changing treatments; furthermore, regularly used pharmacological treatments are expensive and are associated with significant adverse events. These chronic, debilitating conditions can also alter psychological well-being in affected individuals. Thus, rheumatic conditions pose a major public health concern.
It reflects the average number of citations to recent articles published in science and social science journals in a particular year or period, and is frequently used as a proxy for the relative importance of a journal within its field. It is first devised by Eugene Garfield, the founder of the Institute for Scientific Information. The impact factor of a journal is evaluated by dividing the number of current year citations to the source items published in that journal during the previous two years.
Last date updated on September, 2014