Correlation analysis of financial conflicts of interest and favourability of results or conclusions in addiction medicine systematic reviews and meta-analysis

Abstract

Objective To quantify conflicts of interest, assess the accuracy of authors self-reporting them, and examine the association between conflicts of interest and favourability of results and discussions in addiction medicine systematic reviews.Design A search was performed on Medline (Ovid) from January 2016 to 25 April 2020 to locate systematic reviews and meta-analyses focused on treatments of addiction disorders using a systematic search strategy. Data were extracted from each systematic review, including conflict of interest statements, authorship characteristics and the favourability of the results/conclusion sections. A search algorithm was used to identify any undisclosed conflicts of interest on the Open Payments Database (Dollars for Docs), Dollars for Profs, Google Patents/United States Patent and Trade Office, and prior conflict of interest statements in other published works from these authors.Results The search identified 127 systematic reviews, representing 665 unique authors. Of the 127 studies, 81 reported no authors with conflicts of interest, 28 with 1 or more conflict, and 18 had no conflict of interest statement. Additional non-disclosed conflicts of interest were found for 34 authors. There were 69 reviews that had at least one author with a conflict of interest. Of the 69 reviews, 14 (20.3%) reported favourable results and 26 (37.7%) reported favourable discussion/conclusions with no statistically significant association. A subanalysis was performed on publications with only US authors (51) with 35 (68.9%) having at least 1 conflict of interest. US authored studies that had a conflict of interest favoured the results (p = <0.001) and discussion/conclusion (p = 0.018) more often.Conclusion Although multiple undisclosed financial conflicts of interest were found, there was no correlation with the favourability of the results or discussion/conclusions across all addiction medicine systematic reviews. Further research needs to be done on US-based publications and encourage disclosure systems worldwide to provide more accurate reporting.