Worldwide inequality in access to full text scientific articles: the example of ophthalmology

Background: The problem of access to medical information, particularly in low-income countries, has been under discussion for many years. Although a number of developments have occurred in the last decade (e.g., the open access (OA) movement and the website Sci-Hub), everyone agrees that these difficulties still persist very widely, mainly due to the fact that paywalls still limit access to approximately 75% of scholarly documents. In this study, we compare the accessibility of recent full text articles in the field of ophthalmology in 27 established institutions located worldwide. Methods: A total of 200 references from articles were retrieved using the PubMed database. Each article was individually checked for OA. Full texts of non-OA (i.e., paywalled articles) were examined to determine whether they were available using institutional and Hinari access in each institution studied, using alternative ways (i.e., PubMed Central, ResearchGate, Google Scholar, and Online Reprint Request), and using the website Sci-Hub. Results: The number of full texts of paywalled articles available using institutional and Hinari access showed strong heterogeneity, scattered between 0% full texts to 94.8% (mean = 46.8%; SD = 31.5; median = 51.3%). We found that complementary use of alternative ways and Sci-Hub leads to 95.5% of full text paywalled articles, and also divides by 14 the average extra costs needed to obtain all full texts on publishers' websites using pay-per-view. Conclusions: The scant number of available full text paywalled articles in most institutions studied encourages researchers in the field of ophthalmology to use Sci- Hub to search for scientific information. The scientific community and decision-makers must unite and strengthen their efforts to find solutions to improve access to scientific literature worldwide and avoid an implosion of the scientific publishing model. This study is not an endorsement for using Sci-Hub. The authors, their institutions, and publishers accept no responsibility on behalf of readers.