Publication Bias in Coronary Artery Disease Clinical Trials: A Bibliometric Review

The objective of our study was to determine the extent of publication bias of clinical trials pertaining to the treatment of coronary artery disease. Specifically, studies are more likely to be published if the results are positive and have a higher citation rate.

The US National Library of Medicine Clinical Trials database was used to identify a total of 242 terminated and completed clinical trials with reported results since 2017. Studies were excluded if they had fewer than two treatment arms, fewer than five participants in any of the treatment arms, or no data analysis to determine significance. A trial was deemed "positive" if there was a statistically significant difference between the treatment arms that agreed with the hypothesis. A "negative" was not statistically significant and/or did not agree with the hypothesis of the trial. Data were collected on intervention, treatment arms, funding type, publication rates, citation rate, impact factor and H index of the journal.

Of the 144 trials analyzed, 86 had positive results and 58 had negative results. There was a statistically significant difference in the length of study and publication rate. The publication rate for positive studies was 92%, whereas for negative studies it was 50% (P<0.001).

Positive outcomes had a higher publication rate compared with the negative results. Identification of this bias is critical in addressing the impact it could have on the practice of evidence-based medicine. If negative results are not being published, then this pushes physicians to rely on positive results more heavily, thereby skewing evidence-based decision making. This in turn impacts decisions that affect the quality of care.