Conflict of interest reporting by authors involved in promotion of off-label drug use: an analysis of journal disclosures

Abstract

Background: Litigation documents reveal that pharmaceutical companies have paid physicians to promote off-label uses of their products through a number of different avenues. It is unknown whether physicians and scientists who have such conflicts of interest adequately disclose such relationships in the scientific publications they author.

Methods and findings: We collected whistleblower complaints alleging illegal off-label marketing from the US Department of Justice and other publicly available sources (date range: 1996-2010). We identified physicians and scientists described in the complaints as having financial relationships with defendant manufacturers, then searched Medline for articles they authored in the subsequent three years. We assessed disclosures made in articles related to the off-label use in question, determined the frequency of adequate disclosure statements, and analyzed characteristics of the authors (specialty, author position) and articles (type, connection to off-label use, journal impact factor, citation count/year). We identified 39 conflicted individuals in whistleblower complaints. They published 404 articles related to the drugs at issue in the whistleblower complaints, only 62 (15%) of which contained an adequate disclosure statement. Most articles had no disclosure (43%) or did not mention the pharmaceutical company (40%). Adequate disclosure rates varied significantly by article type, with commentaries less likely to have adequate disclosure compared to articles reporting original studies or trials (adjusted odds ratio [OR] = 0.10, 95%CI = 0.02-0.67, p = 0.02). Over half of the authors (22/39, 56%) made no adequate disclosures in their articles. However, four of six authors with ≥ 25 articles disclosed in about one-third of articles (range: 10/36-8/25 [28%-32%]).

Conclusions: One in seven authors identified in whistleblower complaints as involved in off-label marketing activities adequately disclosed their conflict of interest in subsequent journal publications. This is a much lower rate of adequate disclosure than has been identified in previous studies. The non-disclosure patterns suggest shortcomings with authors and the rigor of journal practices. Please see later in the article for the Editors' Summary.

Figure 1. Flowchart categorization of articles in sample according to the adequacy of their conflicts of interest disclosures.

Figure 2. Counts and proportions of articles with adequate disclosure, by author.

Each vertical line is a unique author, and the y-axis shows the number of articles published by that author. The extent of the vertical line above or below zero represents the frequency of adequate and inadequate disclosure for each author.