|Survival analysis is generally defined as a set of methods for analyzing data where the outcome variable is the time until the occurrence of an event of interest. A branch of statistics which studies the amount of time that it takes before a particular events, such as death, occurs. However, the same techniques can be used to study the time until any event. Survival Analysis typically focuses on time to event data. The impact factor of journal provides quantitative assessment tool for grading, evaluating, sorting and comparing journals of similar kind. It reflects the average number ofÂ citationsÂ to recent articles published inÂ science and social science journals in a particular year or period, and is frequently used as aÂ proxyÂ for the relative importance of a journal within its field. It is first devised byÂ Eugene Garfield, the founder of theÂ 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.