Primary publications reporting estimates of the prevalence of possible ghostwriting
| Publication | Measure of possible ghostwriting reported by authors | estimate % (n) |
|---|---|---|
| Cross-sectional surveys reporting ghostwriting | ||
| Flanagin et al27 | Unnamed individual who participated in the writing | 1.4% (11/809) of articles |
| Wislar et al20 | Unnamed individual who participated in the writing | 0.2% (1/622) of articles* |
| Jacobs and Hamilton, Hamilton and Jacobs 25 33 | Undisclosed medical writing assistance not qualifying for authorship | 2005: 61.8% (NR) 2009: 41.7% (NR) 2011: 33.0% (NR) of articles† |
| Cross-sectional surveys reporting combined ghost authoring and ghostwriting | ||
| Flanagin et al27 | Failure to name, as an author, individuals who made substantial contributions to the research or writing or an unidentified medical writer | 11.5% (93/809) of articles |
| Price et al22 | Failure to name, as an author, individuals who made substantial contributions to the research or writing | 24.1% (40/166) of authors |
| Mowatt et al 23 | Individual merited authorship or had assisted with drafting but not listed as an author or acknowledged | 8.8% (32/362) of articles |
| Hao et al32 | English-language speakers assisted with writing but not identified as authors or acknowledged | 10.4% (NR) of authors |
| Dotson and Slaughter28 | Failure to name, as an author, individuals who made substantial contributions to the research or writing | 0.9% (1/112) of articles |
| Wislar et al20 | Failure to name, as an author, individuals who made substantial contributions to the research or writing of the article or an unnamed individual who participated in the writing | 7.9% (49/622) of articles |
| Cross-sectional surveys reporting ghost authoring | ||
| Mirzazadeh et al24 | Failure to name, as an author, individuals who made substantial contributions to the research | 21.4% (25/NR) of authors |
| Ghajarzadeh26 | Failure to name, as an author, students who made substantial contributions to the research‡ | 0.7% (2/296) of articles |
| Vinther and Rosenberg21 | Individual merited authorship but not listed as an author | 2.4% (6/245) of articles |
| Rees et al31 | Individual merited authorship but not listed as an author | 70% (NR/202) of published authors |
| Publication reviews and descriptive analysis reporting possible ghost authoring or ghostwriting | ||
| Healy and Cattell6 | Published articles coordinated by a medical information company, including acknowledged medical writing support§ | 57.3% (55/96) of articles |
| Gøtzsche et al30 | Individuals who wrote the trial protocol, conducted the statistical analyses or wrote the manuscript but were not listed as authors, not members of a study group or steering committee or not disclosed in an acknowledgment | 75.0% (33/44) of trials |
| Ross et al8 | Published reviews associated with Merck support and with a single external author¶ | 69.4% (50/72) of reviews |
*Available as online supplementary data.
†Values represent the mean weighted percentage of publications that were ghostwritten by respondents. Findings were weighted in proportion to the number of manuscripts the respondent wrote per year.
‡Students were classified as ghostwriters if the student was not named as an author and if the results reported in the publications were based on the results of their theses.
§Authors conclude data provide quantification of the possible extent of ghostwriting based on a single drug. Of the 55 published articles that were coordinated through a medical information company, 2 included medical writing assistance that was acknowledged in the published article.
¶Published review articles had been identified from correspondence between Merck and a medical publishing company, from Merck publication status reports, or were affiliated with an author named within the correspondence or publication status reports. The authors did not report whether medical writing assistance was acknowledged in the published article.
NR, not reported.