Background: Clinical practice guidelines make recommendations based on the best available evidence. Proper management and disclosure of financial conflicts of interest (FCOIs) are necessary for trustworthy clinical practice guidelines. This study evaluated the prevalence of FCOIs and quality of evidence underlying the American Diabetes Association (ADA) guidelines.

Methods: Using the Open Payments Database (OPD) between 2018 and 2020, we examined the research and general payments to all authors of the Standards of Medical Care in Diabetes, 2021. The quality of evidence and tone of recommendations were assessed and the associations between the two were evaluated by logistic regression analysis.

Results: Of the 25 guideline authors, 15 (60.0%) were United States (US)-based physicians eligible for the OPD search. Eight (32.0%) and 12 (48.0%) received one or more industry payments one year and three years prior to the guideline publication, respectively. The median total payments (interquartile range) per author were $33,262 ($4,638‒$101,271) in 2020 and $18,053 ($2,529‒$220,659) in 2018-2020. One author received a research payment of over $10,000 undeclared. Of 471 recommendations, 61 (13.0%) and 97 (20.6%) were supported by low-quality evidence and expert opinions, respectively. Also, 439 (93.2%) recommendations had a positive tone. The lower quality of evidence tended to recommend positively with an odds ratio of 1.56 (95% confidence interval: 0.96-2.56, p=0.075) without reaching statistical significance.

Conclusion: A minority of the guideline authors received industry payments from the healthcare industry, and declared FCOIs were mostly accurate. However, the ADA FCOI policy required the guideline authors to declare their FCOIs for one year before publication. A more transparent and rigorous FCOI policy is needed in the ADA guidelines.