All of the articles in our study have now aged 3-years and we report that our initial findings were robust: articles receiving the open access treatment received more article downloads but no more citations [1].

Article Downloads During the first year of publication, open access articles received more than double the number of full-text downloads (119%, 95% C.I. 100% - 140%) and 61% more PDF downloads (95% C.I. 48% - 74%) from a third more unique visitors (32%, 95% C.I. 24% - 41%). Abstract views were reduced by nearly a third (-29%, 95% C.I. -34% - -24%) signaling a reader preference for the full article when available.

Article Citations Thirty-six months after publication, open access treatment articles were cited no more frequently than articles in the control group. Open access articles received, on average, 10.6 citations (95% C.I. 9.2 -12.0) compared to 10.7 (95% C.I. 9.6 - 11.8) for the control group. No significant citation differences were detected at 12, 18, 24 and 30 months after publication.

1. Davis, P. M. 2010. Does Open Access Lead to Increased Readership and Citations? A Randomized Controlled Trial of Articles Published in APS Journals. The Physiologist 53: 197-201. http://www.the-aps.org/publications/tphys/2010html/December/open_access.htm