Scope and Prevalence of Conflicts of Interest Among Highly Cited Peripheral Artery Disease Research Studies

Abstract

Conflicts of interest (COI) potentially influence interpretation of study results for both authors and journal readers. Scientific journals often require author disclosure of relevant conflicts, but this is usually by self-report and seldom includes detailed quantification of reimbursement. The purpose of this analysis was to characterize COI among highly cited research studies related to peripheral artery disease (PAD) in terms of prevalence, quantity of reimbursement, and associations with manuscript characteristics. Highly cited PAD publications from 2012 to 2017 were identified through a Web of Science search using “peripheral artery disease.” Results were then sorted by number of times cited from highest to lowest. Review articles and non-English language publications were excluded. The top 100 most-cited publications were then abstracted for disclosed COI by author. Articles were characterized as basic science or clinical, and clinical publications were subcategorized as observational, medical interventions, or procedural interventions. Disclosures by US authors were queried using the ProPublica Dollars for Docs search tool (linked to the Centers for Medicare and Medicaid Services Open Payments data) based on provider name, specialty, and geographic location. Statistical analysis included descriptive statistics and categorical tests, including the χ2 test. Included publications were cited a mean of 124 ± 200.5 times and had a total of 1137 named authors. A mean of 1.6 ± 4.8 disclosed COI per author were identified. The prevalence of disclosed COI was significantly higher for clinical versus basic science studies (32.1% vs 4.2%; P < .0001). Among the top 10 articles by highest mean number of disclosures per author, the median open payment amount among authors reporting COI was $121,500 (range, $22-$2,630,000), and a total of $1,584,727 in nondisclosed open payments were identified from authors reporting no COI (median, $24,573; range, $12-$457,000). Disclosed COI sorted by journal are shown in the Table. Significant COI were identified among highly cited PAD studies, although the majority of authors reported none. Disclosed COI are significantly more prevalent among clinical versus basic science studies. Authors may have substantial nondisclosed compensation from industry that may be relevant to study results and interpretation. These results suggest that author self-reported COI may be conservatively biased. Readers should consider potential COI, including quantity of author compensation, when interpreting study results.TableMean number of disclosed conflicts of interest (COI) per author among highly cited peripheral artery disease (PAD) studies sorted by journalaJournalJournal Impact Factor (JCR 2017)Total no. of authorsMean COI per authorStandard deviationRangeStroke6.239109.75.50-17New England Journal of Medicine79.258805.990-41Journal of the American College of Cardiology16.8341303.57.10-44American Journal of Medicine5.117234.66.90-21Journal of Endovascular Therapy2.732262.23.50-18Arteriosclerosis Thrombosis and Vascular Biology6.086153.24.50-14JACC Cardiovascular Interventions9.88192.84.40-14Lancet Diabetes and Endocrinology19.313102.53.40-11European Heart Journal23.425462.46.20-30JACC-Cardiovascular Interventions9.881751.94.40-32Circulation18.881311.84.70-37Leukemia10.023161.630-11Annals of Neurology10.244241.14.20-20Journal of the American Medical Association10.244490.82.10-9Catheterization and Cardiovascular Interventions2.60260.50.80-2Journal of the American Society of Nephrology8.655180.51.50-5Journal of Thoracic and Cardiovascular Surgery4.8860.51.20-3Hypertension6.823180.41.40-6Journal of Cardiovascular Surgery1.19550.40.50-1Lancet53.254480.31.60-11Cardiovascular Drugs and Therapy2.77190.20.40-1Journal of Vascular Surgery3.294140.20.60-2Pharmacological Research4.897110.20.40-1Journal of the American Heart Association4.45400.10.20-1aJournals with highly cited studies but zero COI were excluded. Open table in a new tab