Disappearing act Persistence and attrition of uniform resource locators (URLs) in an open access medical journal

Purpose - The aim of this paper is to assess and catalogue the magnitude of URL attrition in a high-impact, open access (OA) general medical journal. Design/methodology/approach - All Public Library of Science Medicine (PLoS Medicine) articles for 2005-2007 were evaluated and the following items were assessed: number of entries per issue; type of article; number of references per entry; number of references that contained URLs; and the access date listed for each URL citation. URLs were then evaluated for accessibility status (i.e. active or defunct). Findings - In total, 1,133 articles were published from 2005-2007 in PLoS Medicine. The 1,133 articles contained 28,177 references, with 2,503 (8.9 per cent) identified as URLs. Non-research articles accounted for a substantially higher percentage of URL references (17.4 per cent) compared to research articles (4.2 per cent). Almost 17 per cent of the URL references were defunct and the rate of URL attrition increased as time elapsed. Research limitations/implications - Information management policy makers need to re-examine the importance of preserving the internet materials long term. Both publisher and author should expand efforts to preserve internet materials. Common guidelines should be developed (e.g. by the International Committee of Medical Journal Editors) and implemented by all publishers to address URL use as references. Originality/value - This article will be of interest to those in the field.