title: Impact factor: good reasons for concern.
abstract: This commentary emphasizes the importance of Hernán's contention that the impact factor's strong dependence on nonquality factors makes it utterly flawed as a way to evaluate quality of journals or papers.
authors.affiliation: Johns Hopkins Bloomberg School of Public Health, Department of Epidemiology, The Johns Hopkins University, Baltimore, MD 21205, USA. mszklo@jhsph.edu
authors.forename: Moyses
authors.initials: M
authors.lastname: Szklo
mesh_terms: D015706:Bibliometrics; D004827:Epilepsy / Q000453:epidemiology*; D006801:Humans; D010380:Peer Review; D010506:Periodicals as Topic / Q000145:classification / Q000706:statistics & numerical data; D011643:Publishing