While trends in scientific collaborations between the US and China have now been described in a general context , — revealing a significant decline in productivity compared to other international partnerships — such trends have yet to be specifically evaluated for the field of ophthalmology, where there is an ever-important emphasis on multinational partnerships for the delivery of state-of-the-art, rigorous, and equitable eye care. , In this study, we explore collaborations between researchers in the US and China in ophthalmology-related literature from 2000 to 2021.
1
Methods
All original, peer-reviewed articles published between 2000 and 2021 listed under the category “Ophthalmology” were obtained from Thomson Reuters’ Web of Science (WoS) database. Alternative forms of publication, including meeting abstracts, letters, and book chapters, were excluded from the search. Articles published by authors affiliated with institutions located either in the US or China were extracted and stratified into three categories: those with US-based affiliations, those with affiliations in China, and those with affiliations in both the US and China. The number of citations for each of these articles was also assessed via the WoS database.
To assess productivity and impact in conjunction with crude publication and citation numbers, obtained via Thomson Reuters’ Web of Science (WoS) database, we calculated a modified Activity Index (AI), Attractivity Index (AAI), adjusted collaborative AI (AIc), and adjusted collaborative AAI (AAIc), defined as follows:
AI = {(N ia /N ih )/(N ba /N bh )}, where N ia = number of publications from the US or from China in a given year; N ih = total number of publications from both the US and China in a given year; N ba = total number of publications from the US or China between 2000 and 2021; N bh = total number of publications from both the US and China between 2000 and 2021.
AAI = {(S ia /S ih )/(S ba /S bh )}, where S ia = number of citations on publications from the US or China in a given year; S ih = total number of citations on publications from both the US and China in a given year; S ba = total number of citations on publications from the US or China between 2000 and 2021; S bh = total number of citations on publications from both the US and China between 2000 and 2021.
AIc = {(N iac /N ihc )/(N bac /N bhc )}, where N iac = number of collaborative publications from the US and China in a given year; N ihc = total number of publications from both the US and China in a given year; N bac = total number of collaborative publications from the US and China between 2000 and 2021; N bhc = total number of publications from both the US and China between 2000 and 2021.
AAIc = {(S iac /S ihc )/(S bac /S bhc )}, where S iac = number of citations on collaborative publications from the US and China in a given year; S ihc = total number of citations on publications from both the US and China in a given year; S bac = total number of citations on collaborative publications from the US and China between 2000 and 2021; S bhc = total number of citations on publications from both the US and China between 2000 and 2021.
Additionally, we compiled the top 100 most-cited articles with US-only, China-only, and US–China affiliations between 2000 and 2021 using the WoS database. To evaluate differences in the scope and the impact of research, we examined the data provided by the WoS database concerning the journal in which the articles were published, as well as the number of times each article has been cited. Furthermore, we characterized the subspecialty focus of the articles as one of the following: retina, glaucoma, cornea, neuro-ophthalmology, and oculoplastics.
2
Results
Both the quantity of ( Fig. 1 A ) and citations accrued by ( Fig. 1 B) ophthalmology-related literature from the US, China, and from US–China collaborations increased in the study period. Authors affiliated with the US amassed the greatest number of articles and citations. The decline in citations for all groups in the latter half of the study period can be attributed to the shorter time elapsed since the articles’ publication. The AI ( Fig. 2 A ) and AAI ( Fig. 2 B) remained stagnant or slightly declined from 2000 to 2021 for research from the US, while these measures increased for research arising from US–China collaborations. These trends persisted even after normalizing the citation numbers ( Fig. 2 C) and the AAI ( Fig. 2 D) by the number of years since publication. The field of ophthalmology has, thus far, withstood the changes in cooperative dynamics that have impacted the broader scientific community.
