Cross-sectional study of Pfizer-sponsored clinical trials: assessment of time to publication and publication history

Objective: To estimate the proportion of Pfizer-sponsored clinical trials that completed in 2010 and are published as manuscripts in the peer-reviewed literature, and to assess the manuscript development history. Design: Retrospective, cross-sectional analysis. Setting: Clinical trials registered in ClinicalTrials.gov that completed in 2010 for approved, Pfizer prescription products in patients or vaccines in healthy participants. Main outcome measures: The proportion of studies for which the primary outcome(s) was published and the median time from study completion to publication. The manuscript development history included the number of times a manuscript was submitted before it was accepted for publication. Results: Among registered clinical trials for which Pfizer was the sponsor that completed in 2010, 76 met all inclusion criteria. The primary outcome(s) for 65 (85%) studies was published in 71 manuscripts; the median time to publication was 31 months (range 3-63 months). Of the remaining 11 studies, 2 had been submitted to at least one journal, 2 had not yet been submitted and 7 had no plans to publish because the study had terminated early due to recruitment challenges. Manuscripts accepted at the first choice journal were published at median time of 28 months (range 8-63, n=31), those accepted at second choice journal were published at 32 months (3-45, n=19), and for those accepted at third choice journal, it was 40 months (range 24-53, n=13). Conclusions: The publication rate and median time to publication from study completion for Pfizer-sponsored studies were comparable to those previously reported for combined analyses of industry and non-industry sectors. Opportunities exist for sponsors, authors and journals to explore ideas that would facilitate more timely publication for clinical trial results. However, to be effective, such changes may need to revisit the entire publication process.