Categorical Analysis:
Given these two breakpoints, and our two endpoints of 1986 and 2019, we categorized the data into three time-based groups: 1986-1996, 1997-2003, and 2004-2019 (Table 2).
Overall, the largest proportion of citations were neutral (45.4%). The majority were accurate (78.9%), non-attributive (78.3%), non-agenda-setting (59.9%), and non-empirical articles (57.7%). Moreover, the majority of articles were published in the U.S. and Canada (69.7%). Articles were published in a wide range of research areas, although papers were concentrated within the areas of neurosciences & neurology (22.6%) anesthesiology (16.2%), and general & internal medicine (15.3%).