Variable Description Outcome Definition
Sign Identified whether the citing article affirmatively, negatively, or neutrally referred to the index study.. Affirmation The article confirmed, supported, depended on, or was influenced by the index study
Negation The article disputed, questioned, or negatively evaluated the index study
Neutral The article took an undefined, non-promotional, non-combative stance toward the index study
Accuracy Similar to past studies that categorized textual evidence in order to examine varying perspectives in areas of interest 53. Accurate The concordance of the presented facts with information from the index study
Inaccurate The citation contained any extraneous, contrasting, assumed, or misleading information in regard to the index study
Neither The citation did not present enough information from the index study to evaluate its accuracy
Attribution Assessed the perceived impact by the scientific community of the index study on opioid prescribing practices, and thus the opioid crisis. Attributed The citation implied or explicitly linked the publication of the index study to the subsequent development of the opioid-related harms
Not Attributed The citation did not mention the opioid crisis or opioid related harms, and did not establish a link between the index study and the opioid crisis
Agenda Setting Whether the index study was fundamental to the motivation or design of the study at hand 54. Agenda Setting The index study was cited in the Introduction or at the beginning of sections (i.e. at the start of the Discussion) and cited as a motivator for subsequent research
Not Agenda Setting The index study was not cited in the Introduction, the start of any other section, and not cited as a motivator
Article Type Identified the citing article as either empirical or non-empirical research. Empirical Articles The article was empirical (quantitative or qualitative) that included data collection, including secondary analyses such as systematic reviews
Non-Empirical Articles All other articles such as commentaries and editorials that did not report new data or analyses