International Publication Trends of Retinopathy of Prematurity Literature Over 40 Years

Purpose: The purpose of this study was to conduct a bibliometric analysis to evaluate the publication trends of retinopathy of prematurity (ROP) literature over time, focusing on geographic and economic origins. Methods: A search for indexed English abstracts was performed in PubMed using search terms “retinopathy of prematurity” or “retrolental fibroplasia” from 1976 to 2015 and divided into 4 decades. Original research articles involving humans were included. Countries were grouped into high-, middle-, and low-income groups using World Bank criteria, and impact factors (IFs) were gathered from 2014 Thomson Reuters Journal Citation Reports. Results: A total of 5425 publications were identified, of which 2045 met the inclusion criteria. The ratios of publications per decade increased over time: 1976 to 1985 (5.4%), 1986 to 1995 (15.8%), 1996 to 2005 (25%), 2006 to 2015 (53.7%; Pearson r = .93, 95% confidence interval: 0.87-0.96). The rates of publications by income group were high—(82.2%), middle—(17.7%), and low—(0.1%). Respective mean (standard deviation) IFs by income group were 2.79 (4.87), 1.23 (1.17), and 0.42 (0.45). Top producing countries were the United States (37%), the United Kingdom (6.7%), India (4.6%), Japan (3.9%), and Turkey (3.5%). There was a significant difference between the time distribution of publications between high- and middle-income groups, where the latter has produced increasing publications in recent years (P < .001), but in journals with lower IFs overall (P < .001). Conclusions: Publications regarding ROP are increasing in number. Investigators from middle-income countries are increasingly contributing to the ROP literature but, overall, may not be recognized yet in journals with high IFs.